Table of contents

The LHCb VELO Timepix3 telescope is a silicon pixel tracking system constructed initially to evaluate the performance of LHCb VELO Upgrade prototypes. The telescope consists of eight hybrid pixel silicon sensor planes equipped with the Timepix3 ASIC . The planes provide excellent charge measurement, timestamping and spatial resolution and the system can function at high track rates. This paper describes the construction of the telescope and its data acquisition system and offline reconstruction software. A timing resolution of 350 ps was obtained for reconstructed tracks. A pointing resolution of better than 2\mum was determined for the 180 GeV/c mixed hadron beam at the CERN SPS . The telescope has been shown to operate at a rate of 5 million particles s⁻¹⋅ cm⁻² without a loss in efficiency.

The procedure for the energy calibration of the high granularity electromagnetic calorimeter PHOS of the ALICE experiment is presented. The methods used to perform the relative gain calibration, to evaluate the geometrical alignment and the corresponding correction of the absolute energy scale, to obtain the nonlinearity correction coefficients and finally, to calculate the time-dependent calibration corrections, are discussed and illustrated by the PHOS performance in proton-proton (pp) collisions at √s=13 TeV. After applying all corrections, the achieved mass resolutions for π⁰ and η mesons for p_T > 1.7 GeV/c are σ_m^π0 = 4.56 ± 0.03 MeV/c² and σ_m^η = 15.3 ± 1.0 MeV/c², respectively.

The generation of frequency-tunable, narrow-bandwidth and carrier-envelope-phase stable THz pulses with fields in the MV/cm regime that can be appropriately timed to the femtosecond X-ray pulses from free-electron-lasers is of highest scientific interest. It will enable to follow the electronic and structural dynamics stimulated by (non)linear selective excitations of matter on few femtosecond time and Ångstrom length scales. In this article, a scheme based on superradiant undulator emission generated just after the XFEL is proposed. The concept utilizes cutting edge superconducting undulator technology and provides THz pulses in a frequency range between 3 and 30 THz with exceptional THz pulse energies. Relevant aspects for realization and operation are discussed point by point on the example of the European XFEL.

Evaluation of liver iron content (LIC) is crucial for the judgment of hepatic iron overload (HIO). Here, we evaluated the potential utility of synchrotron radiation (SR) CT for quantifying LIC in mice suffered from HIO. The mice models of HIO were made by the injection of iron dextran. A series of total iron injection doses of 0, 12.5, 25, 50 and 100 mg were used. SR CT imaging was performed using a detector with the pixel size of 6.5 μm × 6.5 μm at the energy level of 12 keV . The iron micro-depositions were pathologically confirmed using Prussian blue staining. The reconstructed transverse sections were obtained by applying the filtered back projection (FBP) algorithm with PITRE software. 3D visualization was performed using Amira 5.4. LIC was confirmed by an inductively coupled plasma (ICP) spectrometer. SR CT-derived LIC (LIC_CT) was defined as the volume ratio of iron depositions to the liver. The volume ratio was measured using ImageJ software. SR CT presented a high-spatial resolution to clearly display iron micro-depositions in the iron-overload liver. Additionally, iron micro-depositions were found to distribute unevenly on 3D images. The LIC_CTs were 0, (1.890 ± 0.172)%, (4.148± 0.282)%, (6.769± 0.201)%, and (12.912 ± 0.270)% for injection doses of 0 mg, 12.5 mg, 25 mg, 50 mg and 100 mg, respectively. LIC_CT had a strong linear correlation with injection dose (R0²= 0.993, P< 0.0001) or ICP-derived LIC (LIC_ICP) (R² = 0.9644, P < 0.0001). The linear correlation between LIC_CT and LIC_ICP could be expressed by an equation. Using this equation, LIC could be predicted by measuring LIC_CT. Therefore, SR CT imaging showed potential ability to quantify LIC. The imaging modality may be used for the evaluation of disease progression and therapeutic efficacy in mice models.

Timepix3 is a multi-purpose readout ASIC for hybrid pixel detectors. It can measure time and amplitude simultaneously by employing time-of-arrival (ToA) and time-over-threshold (ToT) techniques. Both methods are systematically affected by timewalk. In this paper, a method for pixel-by-pixel calibration of the time response is presented. Assemblies of Timepix3 ASICs bump-bonded to thin planar silicon pixel sensors with thicknesses of 50 μ m, 100 μ m and 150 μ m are calibrated and characterised in particle beams. For minimum ionising particles, time resolutions down to 0.72 ± 0.04 ns are achieved.

As part of detailed optimization studies on Resistive Plate Chambers (RPCs) to be deployed in huge numbers in the INO-ICAL experiment, effects of integration time on the dispersion of the induced charge as well as position resolution of a prototype RPC was studied. Two, G10 based pickup panels of strip widths 5 mm and 3 mm were used in these studies. A double Gaussian function was used to fit the dispersion of the induced charge on the strips due to passage of cosmic ray muons through the RPC.

Chromium compensated GaAs sensors have been characterized using the charge-integrating readout chip JUNGFRAU. Due to its low noise performance and 75 × 75 μm² pixel size, JUNGFRAU enables a precise measurement of the charge (of either polarity) with a high spatial resolution. Several sensor parameters like dark current, noise and spectral performance as well as the charge transport properties of the electrons have been determined. The short lifetime of holes in GaAs:Cr gives rise to an effect where pixels adjacent to a pixel with a photon hit show a strong negative signal when being absorbed close to the readout electrode. This so-called `crater effect' has been simulated and allows an estimation of the hole lifetime in GaAs:Cr.

This paper presents a technique for development of a high-performance and low cost real time PCR detection system based on fluorescence lifetime of fluorescent dyes by using silicon photomultipliers. A high gain passive quenching silicon photomultiplier is used as a detector in a relatively high photon rate condition along with a devised low cost discrete electronic circuitry to implement a detection system in which both time- and frequency-resolved measurements are performed. The requirements and restrictions to implement and test the system for quantification of the amplified dsDNA PCR products are discussed. The SYBR Green I as an intercalating double-stranded DNA fluoresenct-dye has been used to stain PCR products. It is demonstrated that the quantification of PCR products based on fluorescence lifetime by passive quenching silicon photomultiplier, without using any optical filter, is an efficient and cost effective method in real time PCR instrumentation.

For inertial confinement fusion (ICF) studies, a hotspot's ion temperature is a key parameter for assessing implosion performance. Ion temperature not only characterises the energy generated by the central hotspot but also reflects parameters such as the asymmetry and velocity of the implosion. Herein, we present an ion-temperature diagnostic technique for the ICF implosion hotspot based on the neutron time-of-flight method. We use a neutron time-of-flight spectrometer comprising a large-size (18 cm in diameter; 10 cm in thickness) plastic scintillator and a large-calibre (13.3 cm in diameter) fast photomultiplier tube (PMT). The total system uncertainty of this spectrometer is only 13.6% when the DD neutron yield is 3.1 × 10⁷ neutrons per shot and the ion temperature is 1.6 keV. We can use this system to determine the ion temperature when the DD neutron yield is as small as 2.5 × 10⁶ neutrons per shot and the ion temperature is as low as 0.8 keV. We describe a time-of-flight spectrum-analysis method based on deconvolution and low-pass filtering, and we propose a method for determining the optimal filter cutoff frequency by finding the trough of the neutron-energy spectrum. Despite the low neutron yields and low ion temperatures of the direct-drive ICF implosion experiments at the Shenguang-II (SG-II) upgrade facility, we have successfully used this diagnostic technique for the first time to obtain the ion temperature of the implosion hotspot.

Objectives. To differentiate Brucellosis infected goat udder tissues from the normal tissues by depicting their mechano-biological (elasticity, stiffness) properties through laser diode based photoacoustic spectral response (PASR) technique.

Material and methods. In this study mechano-biological (elasticity, stiffness) properties of tissues are explored through custom-build laser diode based PASR technique to distinguish Brucellosis infected goat udder tissues from normal tissues. Total 16 formalin soaked tissue samples (8 normal and 8 Brucellosis infected) were included in the study to determine the efficiency of this technique. The frequency spectral response obtained through PASR is used to distinguish normal and abnormal goat udder tissues. The results of laser diode based PASR are also corroborated with conventional (ns-pulsed laser) PASR and histopathological findings, to determine the effectiveness of the technique.

Results. The number of frequency peaks and the dominant frequency peak obtained through laser diode based PASR is used to distinguish normal and Brucellosis infected goat tissues. For a normal sample, there is only one frequency peak, which corresponds to (0.13 ± 0.03 MHz). In contrast, there are two frequency peaks at (0.16 ± 0.02 MHz) and at (0.78 ± 0.05 MHz) respectively for the Brucellosis infected tissue (second frequency peak being the dominant one). The results were also correlated with the conventional pulsed laser based PASR.

Conclusion. We obtained an efficiency of 95.33% to differentiate Brucellosis infected tissues from normal tissue. Thus the proposed technique has a good potential for distinguishing the Brucellosis infected goat tissues from normal tissue and this technique can go to the fields in future.

Silicon Photomultipliers (SiPM) are photodetectors optimized for the detection of infrared to ultraviolet photons and employed in a wide range of fast timing applications for medical imaging and particle detectors. SiPMs are used to detect the passage of ionizing radiation into matter via the collection of secondary photons emitted by the radiator material. In this work, we have investigated the possibility to detect high intensity X-ray fluxes using the DC current produced by SiPMs exposed directly to the X-ray beam, in absence of any passive converter material, to demonstrate the possibility to measure intense radiation fluxes without saturation of the SiPM response. In our application, the signal-to-noise ratio of the SiPM current during the direct exposition to X-rays is typically larger than 100, providing a robust indication of a positive detection. We show that, for a wide range of operational parameters and X-ray flux intensities, the SiPM current can be correlated to the X-ray beam intensity using a parametrization that describes the data with an accuracy of the order or better than 1%. We also show that the SiPM signal current to dark current ratio is maximum for hundreds of mV above the breakdown voltage, with a weak dependence on temperature. These results open the prospects for interesting applications for monitoring intense X-ray beams, for example beam spatial profiling, and possibly real time dosimetry both in medical and industrial applications.

The presence of heavy minerals, including radionuclides such as ²³⁸U and ²³²Th, in the beach placers outcropping along the western Calabrian coast (South Italy) has been investigated in order to single out the contribution from natural sources to the total radiation level. Assessing the human health radiation risk for these areas is of great importance due to their main touristic destination. With the aim of characterizing the natural radionuclides contents of the Calabrian sands, the correlations existing between their mineralogical and geochemical features and those of the parent rocks have been studied by measuring the sand radionuclides concentrations and decay products and by calculating the outdoor effective dose rate. The radioactivity in the Calabrian beach sediments is for the most part attributed to monazite and, in turn, to the high amount of Th (in the 409–464 ppm range), and is a function of the rock types and of the formation processes. The outdoor dose and effective dose rates for an exposure period of three months are in the range 1045–1240 nGy/h and 0.32–0.37 mSv/y, respectively. Although these values are remarkably higher than the corresponding average world values, they fall within the limits fixed by the Italian legislation, assuming individuals that spend three summer months on the beach. The results obtained for this area of the Southern Italy coastlines can be used as a baseline for future investigations concerning radioactivity background levels, also in other regions. Moreover, the coupling of the present findings with those of epidemiological studies will allow gaining a better evaluation of possible health effects on the population.

The μ-RWELL is a single-amplification stage resistive Micro-Pattern Gaseous Detector (MPGD) . The detector amplification element is realized with a single copper-clad polyimide foil micro-patterned with a blind hole (well) matrix and embedded in the readout PCB through a thin Diamond-Like-Carbon (DLC) sputtered resistive film. The introduction of the resistive layer, suppressing the transition from streamer to spark, allows to achieve large gains (⩾10⁴) with a single amplification stage, while partially reducing the capability to stand high particle fluxes. The simplest resistive layout, designed for low-rate applications, is based on a single-resistive layer with edge grounding. At high particle fluxes this layout suffers of a non-uniform response. In order to get rid of such a limitation different current evacuation geometries have been designed. In this work we report the study of the performance of several high rate resistive layouts tested at the CERN H8-SpS and PSI πM1 beam test facilities. These layouts fulfill the requirements for the detectors at the HL-LHC and for the experiments at the next generation colliders FCC-ee/hh and CepC.

Streak Cameras are an essential diagnostic tool used in shock physics and high energy density physics experiments. Such experiments require well calibrated temporally resolving diagnostics for studying events that occur on the nanosecond to microsecond time scales. The Nevada National Security Site (NNSS) and Sandia National Laboratories (SNL) have built a 42-channel solid state streak camera (SSSC) prototype as a proof of concept for use as a streak camera replacement. This work is part of an ongoing project to develop the technology to a level competitive with analog streak cameras. The device concept, results from electronic and laser testing, along with recent improvements to increase the device's dynamic range will be discussed in this manuscript.

We report an all-in-one waveform generator, lock-in amplifier and Proportional-Integral-Differential (PID) controller, embedded in a single Field Programmable Gate Array (FPGA). The PID controller is advanced with a novel automatic relocking mechanism, which is capable of self-finding and relocking at the desired setpoint upon unlocking of the PID due to disturbances. The instrument is designed in such a way that these devices can either be used individually or simultaneously. Digital implementation via software processing of the associated modules is used and the firmware is embedded in an FPGA IC, which makes it compact and reconfigurable. The instrument consists of a hardware for establishing external linkage and a Python based computer-controlled interface to control it from a remote PC as well as for acquiring and plotting relevant data. A steep roll-off of the filters (6 dB/octave to 24 dB/octave), low noise density (30 nV/√Hz @ 100 kHz) in the lock-in amplifier and a PID bandwidth of 100 kHz makes it useful for wide range of applications. Versatility of the instrument is demonstrated in three different experiments, (i) Auger electron spectroscopy, (ii) low coherence optical tomography and (iii) laser frequency stabilization followed by self identification of the setpoint upon unlocking and automatic relocking to that.

A Near-Infrared (NIR) measurement method based on a digital orthogonal-vector lock-in amplifier (LIA) is presented in this paper. NIR sky background radiation is very weak; to detect the signals obscured by noise, our approach is to use a chopper to modulate the detected signal and demodulate it using an LIA . The effect of the 1/f noise of the detector, dark current and other noise sources can be reduced to improve Signal-to-Noise Ratio (SNR) and the detected signal will be obtained. The orthogonal vector LIA avoids phase shift and achieves high precision measurements using two orthogonal components. In order to simplify the system, data are digitized by an Analog-to-Digital Converter (ADC) and a digital algorithm, running in a Microcontroller Unit (MCU) with ARM cortex-M4, is adopted to implement the LIA . In our scheme, the signal of the detector is amplified and filtered. Then, Phase Sensitive Detection (PSD), Low-Pass Filtering (LPF) and amplitude phase calculation are performed using the digital LIA method. The digital method leads to a greatly simplified circuit design, and adjustment of the time constant of the LPF allows achieving different Equivalent Noise Bandwidths (ENBs) conveniently. The method has the advantage of high precision, flexible usage, simple implementation and low computational resource requirements. Using this method, weak infrared signal submerged in the noise can be picked up easily, which extremely improves the detection capability of the system.

A Shashlyk-type electromagnetic calorimeter(ECal) will be used in the Multi-purpose Detector at Nuclotron-based Ion Collider facility to study the properties of nuclear matter. In this experiment, the ECal detector is responsible for measuring the energy and position of the incident particles, and identifying them with the information obtained from itself and other detectors. This paper analyzes the position resolution of the Tsinghua ECal modules using the data from a beam test in DESY. Several reconstruction methods are studied in detail. With a deep learning based algorithm, the position resolution of the prototypes achieves less than 3.8 mm for 1.6 GeV electron beam, which is improved by about 30% compared to that of traditional charge center of gravity method.

A low energy antiproton transport from the ASACUSA's antiproton accumulation trap (MUSASHI trap) to the antihydrogen production trap (double cusp trap) is developed. The longitudinal antiproton energy spread after the transport line is 0.23±0.02 eV, compared with 15 eV with a previous method used in 2012. This reduction is achieved by an adiabatic transport beamline with several pulse-driven coaxial coils. Antihydrogen atoms are synthesized by directly injecting the antiprotons into a positron plasma, resulting in the higher production rate.

Jet substructure variables for hadronic jets with transverse momenta in the range from 2.5 TeV to 20 TeV were studied using several designs for the spatial size of calorimeter cells. The studies used the full Geant4 simulation of calorimeter response combined with realistic reconstruction of calorimeter clusters. In most cases, the results indicate that the performance of jet-substructure reconstruction improves with reducing cell size of a hadronic calorimeter from Δ η × Δ ϕ = 0.087×0.087, which are similar to the cell sizes of the calorimeters of LHC experiments, by a factor of four, to 0.022×0.022.

Motivated by the need of a rad-hard switch to be used in the future ATLAS Inner Tracker detector (ITk), at Brookhaven National Laboratory we conceived a High-Voltage silicon vertical JFET capable of satisfying most of the strict specifications required for such a switch. By using the available planar technology for the silicon processing, we fabricated in our Clean Room dedicated batches of HV JFETs, first n-type and then p-type channel JFETs. The electrical characterization showed in particular high voltage handling capabilities in the OFF state, for both types of JFETs. In this paper, we describe the design, the fabrication steps and we report the electrical characterization.

The gain of silicon photomultipliers (SiPMs) increases with bias voltage and decreases with temperature. To operate SiPMs at stable gain, the bias voltage can be readjusted to compensate for temperature changes. We have tested this concept with 30 SiPMs from three manufacturers (Hamamatsu, KETEK and CPTA) operating in a climate chamber at CERN by varying temperatures between 1^o C and 48^o C. We built an adaptive power supply that uses a linear dependence of the bias voltage on temperature. We stabilized four SiPMs simultaneously with only one compensation parameter for the readjustment of the bias voltage of four SiPMs. For all tested Hamamatsu and CPTA SiPMs we achieved our goal of limiting gain changes to less than ± 0.5% in the 20–30^oC temperature range.

A technique for manufacturing thin-film resistors on cylindrical substrates is demonstrated. These devices are aimed for application in rare-event detectors that must minimize radioactive backgrounds from trace impurities in electronic components inside the detector. Cylindrical, conducting Ni films were created via electron beam deposition, using a mechanism that rotates the substrate, to demonstrate proof of principle and measure the resistivity on axis and in azimuth. These films are characterized by measurements using a facsimile of the Van Der Pauw method combined with electrostatic simulations. In the two cylindrical samples made we observe anisotropic electrical behavior with resistivities of 1392.5, 888.5 n Ω m around the azimuth and of 81.9, 72.8 n Ω m along the axis of the sample. We show that this anisotropy is not caused just by the electron beam evaporation by measuring a planar rectangle sample made in the same process but without spinning which has estimated resistivities of 66.5, and 71.9 n Ω m in both directions, and calculated resistivity using the standard Van der Pauw equation of 66.1±2.8 n Ω m. In spite of the anisotropy in the cylindrical samples, we show that these films can be used as resistors.

Fast neutron resonance transmission analysis (FNRTA) is an effective method to identify the light nucleus by measuring its characteristic nuclear structure. One of the significant means of performing high-resolution FNRTA is associating a pulsed electron beam-driven photoneutron source with a neutron time of flight (TOF) detection system. The typical beam width which ranges from a few nanoseconds to several microseconds stretches the flight path to tens and even hundreds of meters for the energy resolution requirement and limits the FNRTA to laboratory analysis only. Currently, we can obtain an ultrashort-pulsed electron beam with a width of 8 ps owing to the femtosecond laser techniques. This benefits the energy resolution and accordingly shortens the flight path to a few meters, and dramatically reduces the volume of FNRTA and even makes it moveable. The work reported in this paper configured FNRTA by using an 8-ps-pulsed 45 MeV electron beam-driven photoneutron source and a 5-m TOF. Monte Carlo simulations are utilized to provide a detailed evaluation of the source and the energy resolution of TOF. The results illustrate that a pulsed neutron beam with energies ranging from sub keV to more than 10 MeV and with an intensity of 1.925× 10⁸ n/s could be delivered. The energy resolution is evaluated to less than 1.67% within the energy region of 1–10 MeV. Preliminary resonance experiments of graphite are implemented by placing a graphite block close to the target. The resonance structure can be distinguished from the experimental results.

The aim of the ALICE Collaboration is to study the physics of strongly interacting matter by using the experimental results from a dedicated heavy-ion detector. The Inner Tracking System (ITS) is located at the heart of the ALICE detector surrounding the interaction point. Currently, ALICE is planning to upgrade the ITS for rare probes at low transverse momenta. The new ITS comprises seven layers of silicon pixel sensors on the supporting structure. One goal of the new design is to reduce the material budget (X/X₀) per layer to 0.3% for the inner layers and 0.8% for the middle and outer layers. In this work, we perform simulations based on detailed geometrical descriptions of different supporting structures for the inner and outer barrels by using ALIROOT. Our results indicate that it is possible to reduce the material budget of the inner and outer barrels to the expected value. Manufacturing of such prototypes is also possible.

Radio Frequency Identification (RFID) is a wireless technology used for tracking a tag attached to an object and uniquely identifying it. In the proposed work, an array antenna that has high gain, good impedance matching, good adaptation, and improved reflection coefficient (S₁₁) at 2.40 GHz for the detection system of objects or living things in motion, has been designed and fabricated. The Fire Resistant RT/duroid-5880 substrate is used for the design purpose of the proposed array antenna. The antenna is an array of four elements with an overall dimension of (223.9 × 98 × 1.56) mm³ and has a microstrip line feed matched to 50 Ω. The impedance bandwidth achieved by the design is about 120 MHz (2.357–2.477 GHz) at the 2.40 GHz microwave band and has a reflection coefficient, S₁₁ of about −23.17 dB. The measured gain obtained is around 13 dB. An experimental study of the fabricated prototype of the optimized array antenna is performed and the results verify its good performance.

Recently, cancer has been treated using high dose rates (HDRs), which requires highly reliable treatment plans. In current clinical practice, phosphors are widely used. However, these are of limited use for real-time verification of radiation during HDR brachytherapy; moreover, there is a possibility of electrical error via high-energy radiation because a photodiode is used to detect visible light. Therefore, it is necessary to develop a new dosimeter that can detect gamma rays effectively. This study aimed to investigate the feasibility of a lead monoxide- (PbO)-based dosimeter to detect the position of a radioactive source in HDR brachytherapy. It was confirmed that the fabricated PbO dosimeter has sufficient response coincidence, reproducibility, and dose linearity for gamma rays. Based on these results, it is demonstrated that the PbO dosimeter complies with the general requirements of HDR brachytherapy monitoring systems. Thus, the PbO dosimeter is expected to be used commercially in the future.

The ATLAS Pixel detector is designed to sustain high dose integrated over several years of operation. Nevertheless, the radiation hardness should also favour the survival of the detector in case of accidental beam losses. An experiment performed in 2006 showed that ATLAS Pixel detector modules (silicon planar coupled with FE-I3 electronics) could survive to beam losses up to 1.5⋅10¹⁰ protons/cm² in a single bunch with minimal or no deterioration of performance. The upgrade of LHC to even higher luminosity (HL-LHC) calls for a new test of these properties. Two test beam campaigns have been conducted in 2017 and 2018 at the High-Radiation to Materials (HiRadMat) facility of the CERN Super Proton Synchrotron in order to establish for the first time the survival threshold of different types of ATLAS IBL pixel modules under very intense proton beam irradiation.

The proposed Circular Electron Positron Collider (CEPC) will allow precision Higgs measurements. To meet the stringent physics requirements, its vertex detector will have to be constructed with the state-of-the-art pixel detector technologies that promise high spatial resolution, low power consumption and low material budget. We have conducted R&D based on the emerging CMOS pixel sensor technology and developed the first prototype JadePix-1. In this paper, we describe the sensor structures that are primarily designed to evaluate the impacts of diode geometry on charge collection. We present the detailed test results obtained with radioactive sources and electron beams, and the sensor performance before and after neutron irradiation up to 10¹³ 1 MeV n_eq/cm².

The muon telescopes of the Extreme Energy Events (EEE) Project [1] are made of three Multigap Resistive Plate Chambers (MRPC). The EEE array is composed, so far, of 59 telescopes and is organized in clusters and single telescope stations distributed all over the Italian territory. They are installed in High Schools with the aim to join research and teaching activities, by involving researchers, teachers and students in the construction, maintenance, data taking and data analysis. The unconventional working sites, mainly school buildings with non-controlled environmental parameters and heterogeneous maintenance conditions, are a unique test field for checking the robustness, the low-ageing features and the long-lasting performance of the MRPC technology for particle tracking and timing purposes. The measurements performed with the EEE array require excellent performance in terms of time and spatial resolution, efficiency, tracking capability and stability. The data from two recent coordinated data taking periods, named Run 2 and Run 3, have been used to measure these quantities and the results are described, together with a comparison with expectations and with the results from a beam test performed in 2006 at CERN.

We present a dual-channel optical transmitter (MTx+)/transceiver (MTRx+) for the front-end readout electronics of high-energy physics experiments. MTx+ utilizes two Transmitter Optical Sub-Assemblies (TOSAs) and MTRx+ utilizes a TOSA and a Receiver Optical Sub-Assemblies (ROSA). Both MTx+ and MTRx+ receive multimode fibers with standard Lucent Connectors (LCs) as the optical interface and can be panel or board mounted to a motherboard with a standard Enhanced Small Form-factor Pluggable (SFP+) connector as the electrical interface. MTx+ and MTRx+ employ a dual-channel Vertical-Cavity Surface-Emitting Laser (VCSEL) driver ASIC called LOCld65, which brings the transmitting data rate up to 14 Gbps per channel. MTx+ and MTRx+ have been tested to survive 4.9 kGy(SiO₂).

To provide good performance of spatial and energy measurement for the experiments at the HIRFL-CSR, a double-sided silicon strip detector (DSSD) has been designed as the pixel detector. Performance of the DSSD has been characterized in a vacuum chamber with the alpha source. The reverse leakage current of the DSSD is measured to be ∼3 nA/cm²⋅ 100 μm at the full depleted voltage and the energy resolution of each strip is better than 1%. Besides, the energy information of charge sharing events can be well measured. In this paper, the design, manufacture and performance characterization of the DSSD will be discussed.

The measurement of the energy spectra and densities of α-particles and other fast ions are part of the ITER measurement requirements, highlighting the importance of energy-resolved energetic-particle measurements for the mission of ITER. However, it has been found in recent years that the velocity-space interrogation regions of the foreseen energetic-particle diagnostics do not allow these measurements directly. We will demonstrate this for γ-ray spectroscopy (GRS), collective Thomson scattering (CTS), neutron emission spectroscopy and fast-ion D_α spectroscopy by invoking energy and momentum conservation in each case, highlighting analogies and differences between the different diagnostic velocity-space sensitivities. Nevertheless, energy spectra and densities can be inferred by velocity-space tomography which we demonstrate using measurements at JET and ASDEX Upgrade. The measured energy spectra agree well with corresponding simulations. At ITER, α-particle energy spectra and densities can be inferred for energies larger than 1.7 MeV by velocity-space tomography based on GRS and CTS. Further, assuming isotropy of the α-particles in velocity space, their energy spectra and densities can be inferred by 1D inversion of spectral single-detector measurements down to about 300 keV by CTS. The α-particle density can also be found by fitting a model to the CTS measurements assuming the α-particle distribution to be an isotropic slowing-down distribution.

The phase-2 upgrade of the LHC will require novel pixel readout chips, which deliver hit information at drastically increased data rates and tolerate unprecedented radiation levels. The large-scale prototype chip RD53A has been designed by the RD53 collaboration and manufactured in a 65 nm CMOS process, suitable for the innermost layers of both the ATLAS and the CMS experiment. In order to verify the radiation hardness design goal of 500 Mrad total ionizing dose, RD53A has been irradiated using X-rays. The radiation effects on the performance of the data link, reset circuit and the clock generation have been investigated. Furthermore, the operating margins in terms of supply voltage and frequency have been analyzed.

MedAustron is a synchrotron-based hadron therapy center located in Lower Austria. Accelerated proton beams with energies of 62–252 MeV/u are used to treat patients since 2016. The carbon ion beam is currently under commissioning and will provide treatment in 2019 with energies of 120–400MeV/u. Two of the four irradiation rooms are used for clinical treatment while the preparation of the Gantry beam line is ongoing. Proton beams of up to 800 MeV will be provided for non-clinical research. The Injector features three identical ECRIS from Pantechnik, two of which are used to generate the proton and the carbon beam respectively. The medical environment of the accelerator puts strict requirements on the ion source long-term stability operation. The extracted beam current from the source allow for maximum current fluctuations on the order of ±2.5% on continuous run. In this work we discuss the impact of the ion source performances on the characteristics and stability of the entire accelerator. Further, we discuss the latest progress on carbon commissioning and the future perspectives with particular emphasis on the source requirements.

This paper presents the design and test results of a 4 × 14 Gb/s vertical cavity surface emitting laser (VCSEL) array driver VLAD14 fabricated in 65 nm CMOS technology. A novel output driving stage in VLAD14 is proposed to improve the bandwidth comparing to the conventional structure. VLAD14 outputs a 2 mA bias current and a 6 mA modulation current with a power consumption of 52 mW/ch when working at 14 Gbps/ch. The driver die has been tested with the VCSEL array load and wide-open optical eyes have been captured at 14 Gbps/ch.

In the quest for particle dark matter and physics beyond the Standard Model, the possibility of the existence of neutral long-lived particles (LLPs) has been proposed. The MATHUSLA project has been designed to detect possible LLPs produced in LHC collisions with a surface detector built by exploiting existing technologies. The detector will be installed above one of the high-luminosity interaction regions of the LHC before the beginning of the Phase-2 operation. A small-scale MATHUSLA test detector implemented with two stations of scintillators from the D0 experiment and three stations of Resistive Plate Chambers originally designed for the ARGO experiment was installed and operated above the ATLAS interaction point in November 2017. Each RPC station consisted of two detector layers, about 7 m² each, with orthogonal read-out strips. The results of the test run will be presented.

Bright Stars Survey Telescope (BSST) is a photometry telescope prepared to be installed in the Kunlun station, Antarctica. In this paper, a scientific Charge-coupled Device (CCD) camera with 4K × 4K pixels designed for the BSST running in the extremely low temperature environment of Antarctica is introduced. The mechanics and electronics of the camera are introduced respectively. In the camera design a Thermoelectric Cooler (TEC) is used for the CCD cooling with both air cooling and water cooling for heat dissipation. Separated power and temperature controller (PTC) unit and the camera body reduce the size of the front-end of the camera for satisfying the demand of the size of the telescope. The camera can take images with readout modes of single channel, double channels and four channels. The refrigeration and the readout noise performance have been tested under laboratory condition. The temperature difference of refrigeration can reach 75.7^oC by using water cooling, and the readout noise reach 6.75 e⁻ with readout rate of 100 kHz.

CMOS pixel sensors with a small collection electrode combine the advantages of a small sensor capacitance with the advantages of a fully monolithic design. The small sensor capacitance results in a large ratio of signal-to-noise and a low analogue power consumption, while the monolithic design reduces the material budget, cost and production effort. However, the low electric field in the pixel corners of such sensors results in an increased charge collection time, that makes a fully efficient operation after irradiation and a timing resolution in the order of nanoseconds challenging for pixel sizes larger than approximately forty micrometers. This paper presents the development of concepts of CMOS sensors with a small collection electrode to overcome these limitations, using three-dimensional Technology Computer Aided Design simulations. The studied design uses a 0.18 μm process implemented on a high-resistivity epitaxial layer.

In the next decades, the Large Hadron Collider (LHC) will run at very high luminosity (HL-LHC) 5×10³⁴ cm⁻²s⁻¹, factor five more than the nominal LHC luminosity. During this period the CMS RPC system will be subjected to high background rates which could affect the performance by inducing aging effects. A dedicated longevity program to qualify the present RPC system for the HL-LHC running period is ongoing. At the CERN Gamma Irradiation Facility (GIF++) four RPC detectors, from the spare production, are exposed to an intense gamma radiation for a dose equivalent to the one expected at the HL-LHC . The main detector parameters are under monitoring as a function of the integrated charge and the performance is studied with a muon beam. Preliminary results of the study after having collected ≈ 34% of the expected integrated charge will be presented.

One of the main factors that limits the Hall thruster lifetime is the degradation of surfaces exposed to plasma caused by the flux of energetic ions. Since the magnetic field shapes the plasma properties inside the thruster channel, non-standard magnetic configurations have been proposed in recent years to substantially increase the thruster lifetime. The present article reports an experimental investigation of different magnetic topologies of a Hall thruster operating on xenon and krypton. Plasma properties were measured using probes installed on the channel walls and a fast diving probe. Data are analysed by means of a Bayesian methodology. Results show that magnetic shielding correctly reduces the interaction between the plasma and the channel walls, which can result in lower erosion rates. A comparison between xenon and krypton operation showed that magnetic shielding is less effective for krypton, as the grazing line presents higher temperatures. Fast probe results also show how krypton discharges present wider acceleration regions and higher temperatures inside the channel.

A new neutron camera, comprising twelve individual liquid scintillation detectors, was designed for the Experimental Advanced Superconducting Tokamak (EAST). Twelve assembled neutron detectors will be installed onto the neutron camera, with seven detectors forming a horizontal camera and five detectors forming a vertical camera. These detectors play the main function of measuring the 2.45 MeV neutron emissivity profile. The 2"× 2" BC501A liquid scintillation detector coupled with the gain stabilization system has been developed for neutron measurements and would be applied to the camera. The Assembling and testing of detectors were discussed in details in the second section of this manuscript. The data acquisition system that can automatically acquire neutron information was developed and described in the third part.

Silicon photomultipliers (SiPMs) have high gain, low bias voltage, excellent timing properties and are insensitive to magnetic fields, which have become the best readout choice for advanced positron emission tomography (PET) systems, such as PET/MRI instruments and time-of-flight (TOF) PET imaging. Novel Device Laboratory (NDL) has been developing an unique SiPM technology that uses the bulk resistors in the epitaxial layer as quenching resistors (EQR SiPM); it features small micro cells with high fill factor, fast response to even a single photon, and simple fabrication technology. This paper reports the results to verify that EQR SiPM is promising in the applications of advanced PET imaging. For the EQR SiPM with active area of 3 × 3 mm² and 90000 individual cells, the dark count rate of 6.3 MHz at room temperature, a peak PDE of 34% for 420 nm photons and an intrinsic single photon timing resolution (SPTR) of 81 ps at 9 V over-voltage were obtained. By employing a pair of EQR SiPMs 1-to-1 coupled with 2.84 × 2.84× 6 mm³ LYSO crystals, the energy resolution (ER) of ∼10.1% and the coincidence timing resolution (CTR) of ∼195 ps (FWHM) were demonstrated; by employing a pair of EQR SiPMs 1-to-1 coupled with 2.84 × 2.84× 10 mm³ LYSO crystals, the ER of ∼9.8% and the CTR of ∼226 ps (FWHM) were demonstrated.

A new pixel online monitoring system has been developed to give a fast and intuitive view of the detector performance both offline and online. The source script was written modularly in Python programming language in association with the SQLite and Java languages. It establishes a connection with the CMS detector monitoring database, and extracts and stores detector information into a local database. Among all of the monitored detector parameters, the pixel leakage current is one of the most interesting, as it reflects the accumulated radiation damage of the silicon sensors. The leakage currents obtained from different module positions in the pixel detector are highly correlated with the distance from the beam pipe. Based on the new monitoring system, we have analyzed the pixel detector leakage current evolution since the recent Phase-1 upgrade of the pixel detector and its dependence on the environmental temperature influenced by the cooling loop arrangement inside the pixel detector. The results provide a crucial reference on the detector performance for the re-design of the detector in the Phase-2 upgrade.

Single absorption grating based X-ray phase contrast imaging (XPCI) with a hybrid pixel detector Timepix is a promising technique in many application fields (material sciences, biology, medicine etc.). Conventional coded aperture approach with microfocus source uses two absorption gratings where one of them is moved in steps (so-called phase stepping). In contrast to that, the proposed XPCI approach provides the absorption, phase contrast and dark field images from a single acquisition. This leads to higher mechanical stability of the system and decrease of the delivered dose. Moreover, faster data acquisition increases the usability of the system for CT measurements and dynamic phase radiography. Custom-built laboratory X-ray imaging setup equipped with Timepix detector and nano-focus X-ray tube was utilized for the measurements. The maximal source to detector distance (SDD) available in the setup is roughly 90 cm. Such system can provide long enough phase propagation distance while using the absorption grating with 60 μm strip period, 55 μm large detector pixels and three pixel illumination. The system enables insertion and positioning of both 1D and 2D absorption gratings producing micro-line or micro-pencil beams, respectively. The positioning stages of the used system allow to acquire a series of phase contrast images taken under different angles and thus to carry out phase contrast computed tomography (CT). CT reconstructions were performed by both in-house and commercial software packages. Results of pilot CT measurements of phantoms objects are presented in the contribution.

Beam monitoring system in heavy ion therapy facilities ensures the beam energy deposition can accurately cover the dedicated tumour region. For the purpose of building a high-precision beam monitoring system, a Monolithic Active Pixel Sensor (MAPS) is under development. The charge sensing node in the MAPS is formed by an n-well −p⁻ epitaxial layer junction and it collects charge by drift and diffusion. In order to optimize the performance of the charge sensing node, the depletion region, the diode capacitance, the charge collection efficiency and the charge collection time have been studied with TCAD simulations. This paper discusses the simulation results with different bias voltage, node structures and heavy ion hitting locations.

We present the concept of a new type of silicon tracking sensor called Enhanced Lateral Drift (ELAD) sensor. In ELAD sensors the spatial resolution of the impact position of ionising particles is improved by a dedicated charge sharing mechanism, which is achieved by a non-homogeneous electric field in the lateral direction in the sensor bulk. The non-homogeneous electric field is created by buried doping implants with a higher concentration with respect to the background concentration of the bulk. The resulting position-dependent charge sharing allows for an improved interpolation of the impact position. TCAD-based electric field simulations for 2D and 3D geometries as well as transient simulations with a traversing particle for the 2D geometry have been carried out. The electric field profiles have further been optimised for position resolution. The simulations show a strong dependence of the charge sharing mechanism on the buried implant concentration. Optimal values for the buried implant concentration allow for nearly linear charge sharing between two readout electrodes as a function of the impact position. Additionally, the foreseen production technique combining silicon epitaxy and ion beam implantation is outlined.

The Inner Tracking System (ITS) of the ALICE experiment will be upgraded during the second long LHC shutdown in 2019–2020. The main goal of the ALICE ITS upgrade is to enable high precision measurements of low-momentum particles (<1 GeV/c) by acquiring a large sample of events, benefiting from the increase of the LHC instantaneous luminosity of Pb-Pb collisions to  = 6 ⋅ 10²⁷ cm⁻² s⁻¹  during Run 3. Working in this direction the ITS upgrade project is focusing on the increase of the readout rate, on the improvement of the impact parameter resolution, as well as on the improvement of the tracking efficiency and the position resolution. The major setup modification is the substitution of the current ITS with seven layers of silicon pixel detectors. The ALPIDE chip, a CMOS Monolithic Active Pixel Sensor (MAPS), was developed for this purpose and offers a spatial resolution of 5 μm. The use of MAPS together with a stringent mechanical design allows for the reduction of the material budget down to 0.35% X₀ for the innermost layers and 1% X₀ for the outer layers. The detector design was validated during the research and development period through a variety of tests ensuring the proper operation for the full lifetime inside ALICE. The production phase is close to completion with all the new assembled components undergoing different tests that aim to characterize the modules and staves and determine their qualification level. This contribution describes the detector design, the measurements performed during the research and development phase, as well as the production status.

In view of the tracking detector application to the ATLAS High Luminosity LHC (HL-LHC) upgrade, we have developed a new generation of High Voltage CMOS (HV-CMOS) monolithic pixel-sensor prototypes featuring the AMS aH18 (180 nm) commercial CMOS technology. By fully integrating both analog and digital readout-circuitry on the same particle-detecting substrate, current challenges of hybrid sensor technologies, i.e., larger readout input-capacitance, lower production-yield, and higher production and integration cost, can be downscaled. The large electrode design using high-resistivity substrates actively helps to mitigate the charge-trapping effects, making these chips radiation hard. The surface and bulk damage induced in high irradiation environment change the effective doping concentration of the device, which modulates high electric fields as the reverse-bias voltage increases. This effect can cause high leakage current and premature electrical breakdown, driven by impact ionization. In order to assess the characteristics of heavily irradiated samples, we have carried out dedicated campaigns on ATLASPix1 chips that included irradiations of neutrons and protons, made at different facilities. Here, we report on the electrical characterization of the irradiated samples at different ambient conditions, also in comparison to their pre-irradiation properties. Results demonstrate that hadron irradiated devices can be safely operated at a voltage high enough to allow for high efficiency, up to the fluence of 2× 10¹⁵ n_eq/cm², beyond the radiation levels (TID and NIEL) expected in the outermost pixel layers of the new ATLAS tracker for HL-LHC.

Calorimetry in high-energy physics is rapidly evolving, with new challenges and a wide variety of technologies being employed, both for signal creation and detection. Advances in large-area highly-segmented detectors are providing possibilities for high-granularity calorimetry. The CMS HGCAL, being designed to replace the existing CMS endcap calorimeters for the HL-LHC era, is one example. It is a sampling calorimeter, featuring unprecedented transverse and longitudinal readout segmentation for both electromagnetic (CE-E) and hadronic (CE-H) compartments. This will facilitate particle-flow calorimetry, where the fine structure of showers can be measured and used to enhance pileup rejection and particle identification, whilst still achieving good energy resolution. The CE-E and a large fraction of CE-H will use hexagonal silicon sensors as active detector material. The lower-radiation environment will be instrumented with scintillator tiles with on-tile SiPM readout. An overview of the HGCAL project will be presented, covering motivation, engineering design, readout and trigger concepts, and performance in simulation.

The paper presents latency and performance study of the monitoring system for plasma impurities radiation in a tokamak. The developed solution measures radiation in Soft X-Ray range and can provide valuable information about the ongoing experiment with low latency. This work presents the test configuration with a single-dimensional pixel topology, with 64 channels, tested at photon rate about 100 kHz per channel. The hardware consists of the GEM-based detector, FPGAs, PCIe transmission system and the computer system with 64-bit x86 architecture. The software is the C/C++ code optimized for the execution time and working in the global trigger mode. The system uses raw data acquisition and the backend computations in CPU to provide high accuracy and high-quality results, not easily achievable otherwise. The research includes measurements of the throughput of the system and the latency of the whole data path - between the pulse detection in FPGA and storing of spectroscopy histograms in the file system in memory. The direction of improvements and further development were proposed.

Engineering education needs simulation studies and it is the best way of understanding engineering concepts with minimal cost and energy. The main focus of this present work is to provide a workspace especially in LabVIEW for analyzing the performance of the system and to operate them in stable and controlled regions. LabVIEW is a simulation platform which facilitates the simulation of various systems and their response with various controllers programmed using functional blocks that are easy to understand. In this work, the benchmark test systems like DC series motor as first order system, general second order system and a Real time rotary Inverted Pendulum (RIP) model which has been reduced with high order system reduction technique are considered. The test systems are controlled with PID controller tuned by various tuning methods. The PID controller is tuned with conventional methods like Ziegler-Nichols (ZN), Internal Model Control (IMC), and Direct Synthesis (DS) and the responses of the systems are analysed in LabVIEW platform. The common platform has been developed and tested for supporting the performance and analysis of the system with adjustable PID controller parameters like proportional gain K_p, integral time constant T_i, and derivative time constant T_d. The performance specifications are phase margin, gain margin, bandwidth, settling time, rise time and integral errors. This LabVIEW platform facilitates the learners to analyze the system effectively with various controllers and their performance parameters are compared easily.

B-RAD is a hand-held radiation survey meter, specifically designed for operation in regions of strong magnetic field. The instrument has been jointly developed by CERN Radiation Protection group and the Department of Energy of the Polytechnic of Milan (POLIMI), originally to perform measurements of the residual radioactivity (radiation surveys) in the experimental areas of CERN Large Hadron Collider (LHC) and inside the ATLAS detector without switching the magnetic field off. B-RAD is based on a scintillating crystal coupled to Silicon Photomultipliers, and its operation is unaffected by magnetic field intensity up to 3 T. Five engineered prototype units were built and made available for routine use at CERN. The design of the instrument has subsequently been licenced to a company in order to industrialise it. This paper describes the CERN-POLIMI engineered version of the instrument, discusses its characterization in details and provides an overview of the commercial unit.

Wafers with different epitaxial layer thicknesses of 12, 18, 20, 25, 30 and 40 μm and high resistivities ranging from 0.03 to 8.0 kΩ⋅cm have been investigated in this study. To verify their properties, surface resistivity measurement, scanning electron microscopy inspection and spreading resistance profiling have been performed. The results indicate that wafers with a 25-μm epitaxial thickness are well-suited to our requirements for use as a starting material for ALPIDE chip production in the ALICE ITS upgrade project.

In this work we report the imaging performance of a small field of view planar scintigraphic system for low and medium energy radiotracers imaging. ^99mTc (140 keV) and ⁶⁷Ga (93 keV (P1, 42%), 184 keV (P2, 21%), 300 keV (P3, 17%), 393 keV (P4, 5%)) radioisotopes were used to evaluate the nuclear imaging detector in terms of non-uniformity, energy resolution, system spatial resolution and system sensitivity. Moreover, detector's ability to reliably quantify activity variations in the useful field of view has been evaluated. Specific collimator for given photon energy range is needed, in order to reduce image degradation due to photon scattering and penetration. Three parallel hole collimators different in geometry were studied. Results show that all of them are suitable for ^99mTc and ⁶⁷Ga molecular imaging applications, given that only the first photopeak in the case of ⁶⁷Ga has to be used for imaging. In this case, accurate quantitative information is obtained with all 3 collimators for both radioisotopes. For ^99mTc the most appropriate collimator is the one with the thinner septa walls and the lower height, while for ⁶⁷Ga the thickest septa and higher height collimator. Dual isotope imaging is applicable using appropriate energy windows and appropriate collimator depending on the application.

Baseline shift seriously affects the accuracy of elemental analyzing when prompt gamma neutron activation analysis (PGNAA) technique is used in industry fields. Baseline is affected by signal pile-ups and environmental factors. We propose a photomultiplier tube (PMT) gating method to eliminate the effects of the environmental factors. The detector system updates the baseline before each single measurement starts. We propose an algorithm to restore the baseline shift caused by signal pile-ups. Test result shows that with the gating method, the hydrogen characteristic peak position fluctuation is reduced by half of the original value. And the resolution does not increased by the using of the gating method.

A high performance multichannel analyzer (MCA) based on traditional used pulse forming method and high-speed waveform sampling technology was developed in this paper for spectra analysis and radioactive measurement. The self-developed MCA is composed of conditioning part and processing part. The conditioning part including pole-zero cancellation, polarity conversion, programmable amplification, active integral filter, baseline recovery and peak holding is adopted to realize amplification, Gauss shaping and peak holding functions, while the processing part mainly including dither circuit, 16-bit 100 MHz high speed ADC and FPGA is employed to make waveform sampling and spectra acquisition. The performance including the differential nonlinearity (DNL), integral nonlinearity (INL) and energy resolution are studied by using precision sliding pulse generator, NaI scintillator detector and radiation sources. The results show that the DNL and INL of the MCA are better than 1.06% and 0.09% respectively, and the energy resolution measured with NaI scintillator detector at 0.662 MeV is about 7.82%. In addition, the DNL value depends on the appropriate selection of dither channels, and the optimal dither channel is 64 for the self-developed MCA in this paper. At last, the overall performance of the self-developed MCA is compared with a commercially available NIM plug-in type MCA, the results indicate that the MCA designed in this paper is obviously better than the commercially available MCA.

A small sample stretcher for in-situ measurement of small angle X-ray scattering (SAXS) was developed, which consists of stretch, transmission, detection and control systems. The basic parameters of the stretcher are: tension ⩾ 400 N, 3 mm/min ⩽ stretching speed ⩽ 50 mm/min, sample length ⩽ 30 mm, stroke ⩾ 80 mm, and resolution = 50 μm. The stretcher is compact and has low stretching speed and convenient remote control. It is suitable for in-situ SAXS measurements on stretching of carbon fibers, polyethylene and other samples. Such measurement were carried out with high density polyethylene (HDPE) on the SAXS instrument at the 1W2A station of Beijing Synchrotron Radiation Facility (BSRF). The result verified the effectiveness of the stretcher.

Linear alkyl benzene (LAB) has in recent years been used as a solvent for PPO in large-scale scintillation detectors, like Daya Bay and SNO+. The combination has several nice properties, including high light yield, good materials compatibility, and excellent pulse shape discrimination. As charged particles move through the LAB+PPO, both Cherenkov and scintillation light are created. Separating Cherenkov from scintillation light would allow a broad range of physics in future large-scale detectors like THEIA, by allowing direction reconstruction with Cherenkov light while retaining the high light yield and good particle ID of a scintillator detector. In this paper, we examine the discrimination of Cherenkov and scintillation light using a set of bandpass and dichroic filters. In principle, Cherenkov light emission extends longer in wavelength than the PPO scintillation spectrum, allowing for exclusive identification. We find that by selecting wavelengths above 450 nm the Cherenkov light can be clearly separated from the scintillation light.