002722395 001__ 2722395
002722395 005__ 20250607055451.0
002722395 0248_ $$aoai:cds.cern.ch:2722395$$pcerncds:CERN$$pcerncds:CERN:FULLTEXT$$pcerncds:FULLTEXT
002722395 0247_ $$2DOI$$9arXiv$$a10.1016/j.nima.2020.164657$$qpublication
002722395 037__ $$9arXiv$$aarXiv:2006.05966$$cphysics.ins-det
002722395 035__ $$9arXiv$$aoai:arXiv.org:2006.05966
002722395 035__ $$9Inspire$$aoai:inspirehep.net:1800509$$d2025-06-06T15:28:28Z$$h2025-06-07T02:00:40Z$$mmarcxml$$ttrue$$uhttps://inspirehep.net/api/oai2d
002722395 035__ $$9Inspire$$a1800509
002722395 041__ $$aeng
002722395 100__ $$aCharlton, M.$$uSwansea U.$$vDepartment of Physics, College of Science, Swansea University, SA2 8PP Swansea, United Kingdom
002722395 245__ $$9Elsevier$$aPositron production using a 9 MeV electron linac for the GBAR experiment
002722395 269__ $$c2020-06-10
002722395 260__ $$c2021-01-01
002722395 300__ $$a33 p
002722395 500__ $$aSubmitted to Nucl.Instrum.Meth.
002722395 500__ $$9Inspire$$aSubmitted to Nucl.Instrum.Meth.
002722395 500__ $$9arXiv$$apublished in NIM A. 33 pages 9 figures
002722395 520__ $$9Elsevier$$aFor the GBAR (Gravitational Behaviour of Antihydrogen at Rest) experiment at CERN’s Antiproton Decelerator (AD) facility we have constructed a source of slow positrons, which uses a low-energy electron linear accelerator (linac). The driver linac produces electrons of 9 MeV kinetic energy that create positrons from bremsstrahlung-induced pair production. Staying below 10 MeV ensures no persistent radioactive activation in the target zone and that the radiation level outside the biological shield is safe for public access. An annealed tungsten-mesh assembly placed directly behind the target acts as a positron moderator. The system produces 5×107 slow positrons per second, a performance demonstrating that a low-energy electron linac is a superior choice over positron-emitting radioactive sources for high positron flux.
002722395 520__ $$9arXiv$$aFor the GBAR (Gravitational Behaviour of Antihydrogen at Rest) experiment at CERN's Antiproton Decelerator (AD) facility we have constructed a source of slow positrons, which uses a low-energy electron linear accelerator (linac). The driver linac produces electrons of 9 MeV kinetic energy that create positrons from bremsstrahlung-induced pair production. Staying below 10 MeV ensures no persistent radioactive activation in the target zone and that the radiation level outside the biological shield is safe for public access. An annealed tungsten-mesh assembly placed directly behind the target acts as a positron moderator. The system produces $5\times10^7$ slow positrons per second, a performance demonstrating that a low-energy electron linac is a superior choice over positron-emitting radioactive sources for high positron flux.
002722395 540__ $$3preprint$$aarXiv nonexclusive-distrib 1.0$$uhttp://arxiv.org/licenses/nonexclusive-distrib/1.0/
002722395 540__ $$3preprint$$aCC BY-NC-SA 4.0$$uhttp://creativecommons.org/licenses/by-nc-sa/4.0/
002722395 542__ $$3publication$$dElsevier B.V.$$g2020
002722395 65017 $$2arXiv$$aphysics.ins-det
002722395 65017 $$2SzGeCERN$$aDetectors and Experimental Techniques
002722395 690C_ $$aCERN
002722395 690C_ $$aARTICLE
002722395 693__ $$aCERN AD$$eGBAR AD-7
002722395 700__ $$aChoi, J.J.$$uSeoul Natl. U., Dept. Phys. Astron.$$vDepartment of Physics and Astronomy, Seoul National University, 599 Gwanak-Ro, Gwanak-gu, 08826 Seoul, Korea
002722395 700__ $$aChung, M.$$uUNIST, Ulsan$$vDepartment of Physics, Ulsan National Institute of Science and Technology (UNIST), 50
002722395 700__ $$aCladé, P.$$jORCID:0000-0001-5070-8734$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aComini, P.$$jORCID:0000-0002-6373-4752$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aCrépin, P.P.$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aCrivelli, P.$$uZurich, ETH$$vInstitute for Particle Physics and Astrophysics, ETH Zrich, CH-8093 Zrich, Switzerland
002722395 700__ $$aDalkarov, O.$$uLebedev Inst.$$vP. N. Lebedev Physical Institute, 53 Leninsky Prospect, 117991 Moscow, Russia
002722395 700__ $$aDebu, P.$$jORCID:0000-0003-2988-5052$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aDodd, L.$$uSwansea U.$$vDepartment of Physics, College of Science, Swansea University, SA2 8PP Swansea, United Kingdom
002722395 700__ $$aDouillet, A.$$uSaclay$$uParis, Lab. Kastler Brossel$$vpresent address: CEA Saclay, POSITHÔT, 91191 Gif sur Yvette, France$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aGuellati-Khélifa, S.$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aHervieux, P.A.$$uIPCMS, Strasbourg$$vInstitut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Université de Strasbourg, CNRS, F-67000 Strasbourg, France
002722395 700__ $$aHilico, L.$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aHusson, A.$$jORCID:0000-0001-9798-0655$$uCSNSM, Orsay$$vUniversite Paris, Sud -Paris 11, CSNSM IN2P3
002722395 700__ $$aIndelicato, P.$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aJanka, G.$$uZurich, ETH$$vInstitute for Particle Physics and Astrophysics, ETH Zrich, CH-8093 Zrich, Switzerland
002722395 700__ $$aJonsell, S.$$jORCID:0000-0003-4969-1714$$uStockholm U.$$vDepartment of Physics, Stockholm University, SE-10691 Stockholm, Sweden
002722395 700__ $$aKarr, J-P$$jORCID:0000-0003-2082-0914$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aKim, B.H.$$uSeoul Natl. U., Dept. Phys. Astron.$$vDepartment of Physics and Astronomy, Seoul National University, 599 Gwanak-Ro, Gwanak-gu, 08826 Seoul, Korea
002722395 700__ $$aKim, E-S.$$vDepartment of Accelerator Science, Korea University Sejong Campus, Sejong-ro 2511, Sejong, 0019, Republic of Korea
002722395 700__ $$aKim, S.K.$$vDepartment of Physics and Astronomy, Seoul National University, 599 Gwanak-Ro, Gwanak-gu, Seoul, 08826, Republic of Korea
002722395 700__ $$aKo, Y.$$uIBS, Daejeon, CUP$$uSeoul Natl. U., Dept. Phys. Astron.$$vCenter for Underground Physics, Institute for Basic Science, 70 Yuseong-daero 1689-gil, Yuseong-gu, 34047 Daejeon, Korea$$vDepartment of Physics and Astronomy, Seoul National University, 599 Gwanak-Ro, Gwanak-gu, 08826 Seoul, Korea
002722395 700__ $$aKosinski, T.$$jORCID:0000-0003-2052-4269$$uNCBJ, Swierk$$vNational Centre for Nuclear Research (NCBJ), ul. Andrzeja Sotana 7, 05-400 Otwock, Swierk, Poland
002722395 700__ $$aKuroda, N.$$jORCID:0000-0003-2727-790X$$uTokyo U., Komaba$$vInstitute of Physics, University of Tokyo, 3-8-1 Komaba, 153-8902 Tokyo, Japan
002722395 700__ $$aLatacz, B.$$jORCID:0000-0003-2320-1713$$uWako, RIKEN$$uIRFU, Saclay$$vpresent address: RIKEN, Ulmer Fundamental Symmetries Laboratory, 351-0198 Wako, Japan$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aLee, H.$$uSeoul Natl. U., Dept. Phys. Astron.$$vDepartment of Physics and Astronomy, Seoul National University, 599 Gwanak-Ro, Gwanak-gu, 08826 Seoul, Korea
002722395 700__ $$aLee, J.$$uIBS, Daejeon, CUP$$vCenter for Underground Physics, Institute for Basic Science, 70 Yuseong-daero 1689-gil, Yuseong-gu, 34047 Daejeon, Korea
002722395 700__ $$aLeite, A.M.M.$$jORCID:0000-0003-2389-3078$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aLévêque, K.$$uIPCMS, Strasbourg$$vInstitut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Université de Strasbourg, CNRS, F-67000 Strasbourg, France
002722395 700__ $$aLim, E.$$vDepartment of Accelerator Science, Korea University Sejong Campus, Sejong-ro 2511, Sejong, 0019, Republic of Korea
002722395 700__ $$aLiszkay, L.$$jORCID:[email protected]$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aLotrus, P.$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aLouvradoux, T.$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aLunney, D.$$uCSNSM, Orsay$$vUniversite Paris, Sud -Paris 11, CSNSM IN2P3
002722395 700__ $$aManfredi, G.$$uIPCMS, Strasbourg$$vInstitut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Université de Strasbourg, CNRS, F-67000 Strasbourg, France
002722395 700__ $$aMansoulié, B.$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aMatusiak, M.$$uNCBJ, Swierk$$vNational Centre for Nuclear Research (NCBJ), ul. Andrzeja Sotana 7, 05-400 Otwock, Swierk, Poland
002722395 700__ $$aMornacchi, G.$$uCERN$$vCERN, 1211 Geneva 23, Switzerland
002722395 700__ $$aNesvizhevsky, V.V.$$uLaue-Langevin Inst.$$vInstitut Max von Laue -Paul Langevin (ILL), 71 avenue des Martyrs, F-38042 Grenoble, France
002722395 700__ $$aNez, F.$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aNiang, S.$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aNishi, R.$$uTokyo U., Komaba$$vInstitute of Physics, University of Tokyo, 3-8-1 Komaba, 153-8902 Tokyo, Japan
002722395 700__ $$aNourbaksh, S.$$uCERN$$vCERN, 1211 Geneva 23, Switzerland
002722395 700__ $$aPark, K.H.$$uSeoul Natl. U., Dept. Phys. Astron.$$vDepartment of Physics and Astronomy, Seoul National University, 599 Gwanak-Ro, Gwanak-gu, 08826 Seoul, Korea
002722395 700__ $$aPaul, N.$$jORCID:0000-0003-4469-780X$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aPérez, P.$$jORCID:0000-0003-1407-1582$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aProcureur, S.$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aRadics, B.$$uZurich, ETH$$vInstitute for Particle Physics and Astrophysics, ETH Zrich, CH-8093 Zrich, Switzerland
002722395 700__ $$aRegenfus, C.$$uZurich, ETH$$vInstitute for Particle Physics and Astrophysics, ETH Zrich, CH-8093 Zrich, Switzerland
002722395 700__ $$aRey, J.M.$$uIRFU, Saclay$$vpresent address: CEA Saclay, POSITHÔT, 91191 Gif sur Yvette, France$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aReymond, J.M.$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aReynaud, S.$$jORCID:0000-0002-1494-696X$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aRoussé, J.Y.$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aRousselle, O.$$uParis, Lab. Kastler Brossel$$vLaboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Case 74; 4, place Jussieu, F-75005 Collège de France, Paris, France
002722395 700__ $$aRubbia, A.$$uZurich, ETH$$vInstitute for Particle Physics and Astrophysics, ETH Zrich, CH-8093 Zrich, Switzerland
002722395 700__ $$aRzadkiewicz, J.$$uNCBJ, Swierk$$vNational Centre for Nuclear Research (NCBJ), ul. Andrzeja Sotana 7, 05-400 Otwock, Swierk, Poland
002722395 700__ $$aSacquin, Y.$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aSchmidt-Kaler, F.$$uMainz U., Inst. Phys.$$vQUANTUM, Institut fr Physik, Johannes Gutenberg Universität, D-55128 Mainz, Germany
002722395 700__ $$aStaszczak, M.$$uNCBJ, Swierk$$vNational Centre for Nuclear Research (NCBJ), ul. Andrzeja Sotana 7, 05-400 Otwock, Swierk, Poland
002722395 700__ $$aTuchming, B.$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aVallage, B.$$jORCID:0000-0003-1255-8506$$uIRFU, Saclay$$vIRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette Cedex, France
002722395 700__ $$aVoronin, A.$$uLebedev Inst.$$vP. N. Lebedev Physical Institute, 53 Leninsky Prospect, Moscow, 117991, Russia
002722395 700__ $$aWelker, A.$$jORCID:0000-0003-4435-0208$$uCERN$$vCERN, 1211 Geneva 23, Switzerland
002722395 700__ $$aVan Der Werf, D.P.$$jORCID:0000-0001-5436-5214$$uSwansea U.$$vDepartment of Physics, College of Science, Swansea University, SA2 8PP Swansea, United Kingdom
002722395 700__ $$aWolf, S.$$uMainz U., Inst. Phys.$$vQUANTUM, Institut fr Physik, Johannes Gutenberg Universität, D-55128 Mainz, Germany
002722395 700__ $$aWon, D.$$uSeoul Natl. U., Dept. Phys. Astron.$$vDepartment of Physics and Astronomy, Seoul National University, 599 Gwanak-Ro, Gwanak-gu, 08826 Seoul, Korea
002722395 700__ $$aWronka, S.$$jORCID:0000-0003-3277-138X$$uNCBJ, Swierk$$vNational Centre for Nuclear Research (NCBJ), ul. Andrzeja Sotana 7, 05-400 Otwock, Swierk, Poland
002722395 700__ $$aYamazaki, Y.$$uWako, RIKEN$$vUlmer Fundamental Symmetries Laboratory, RIKEN, 2-1 Hirosawa, 351-0198 Wako, Saitama, Japan
002722395 700__ $$aYoo, K.H.$$uUNIST, Ulsan$$vDepartment of Physics, Ulsan National Institute of Science and Technology (UNIST), 50
002722395 773__ $$c164657$$mpublication$$pNucl. Instrum. Methods Phys. Res., A$$v985$$xNucl. Instrum. Methods Phys. Res. A 985, 164657 (2021)$$y2021
002722395 8564_ $$82233311$$s688533$$uhttp://cds.cern.ch/record/2722395/files/2006.05966.pdf$$yFulltext
002722395 8564_ $$82233312$$s32902$$uhttp://cds.cern.ch/record/2722395/files/figure7.png$$y00006 Positron annihilation signal as a function of the voltage of the grid of the retarding field analyzer at 50~V moderator voltage. At low grid potential all positrons are annihilated on the target while above approximately 60~V all particles are repelled by the grid and no positron signal is detected. The continuous line is a fit with a complementary error function, giving $\sigma_{\parallel t}=$4.2~eV. The dotted line shows the corresponding Gaussian energy distribution. The measurement was performed in a 60~mT longitudinal magnetic field.
002722395 8564_ $$82233313$$s6745$$uhttp://cds.cern.ch/record/2722395/files/figure6.png$$y00005 Slow positron flux as a function of the moderator annealing temperature. The measurement was performed using the 4.3 MeV Saclay linac with 1 mm thick tungsten target. The temperature was estimated on the basis of the heating power and radiative heat exchange.
002722395 8564_ $$82233314$$s6927$$uhttp://cds.cern.ch/record/2722395/files/figure5.png$$y00004 Slow positron flux as a function of the moderator temperature. The measurement was performed using the 4.3 MeV Saclay linac with 1 mm thick tungsten target. The temperature was estimated on the basis of the heating power and radiative heat exchange.
002722395 8564_ $$82233315$$s19207$$uhttp://cds.cern.ch/record/2722395/files/figure4.png$$y00003 Slow positron flux as a function of the number of mesh layers (solid circles). Each layer is a 18x18~mm piece of tungsten mesh with 180 wires/inch density, annealed at higher than 2700~K temperature. The measurement was performed using the 4.3~MeV Saclay linac with a 1~mm thick tungsten target. A linear fit of the data points up to 9 layer thickness is shown with a dotted line. Results of a simple simulation (see text) are displayed with open circles. The dashed line is guide for the eye.
002722395 8564_ $$82233316$$s25875$$uhttp://cds.cern.ch/record/2722395/files/figure3.png$$y00002 Cross section of the electron target. The potential of the moderator is +50~V, the rest of the structure is at ground (GND). The copper block (``Cu cooler'') is water cooled. The magnetic field of 9.7 mT is parallel with the electron and positron beams.
002722395 8564_ $$82233317$$s7561$$uhttp://cds.cern.ch/record/2722395/files/figure2.png$$y00001 Positrons created by 9~MeV electrons and stopped in a tungsten plate (\textsc{Geant4} simulation with $10^7$ electrons). The number of positrons annihilating in 0.05~mm thick layers is plotted as a function of the depth. The dashed line at 1 mm shows the thickness of the actually used electron target.
002722395 8564_ $$82233318$$s215911$$uhttp://cds.cern.ch/record/2722395/files/figure1.png$$y00000 Schematic view of the linac (vertical structure on the left) and the positron transfer line. The transfer fields are generated by solenoids wound around the beam pipes and by the two larger coils placed around the linac target. The coil at 45 degrees position is used to fine-tune the magnetic field at the point where the positron beam turns sharply. The beam line crosses the biological shield at the ``S'' shaped section on the right.
002722395 8564_ $$82233319$$s25274$$uhttp://cds.cern.ch/record/2722395/files/figure9.png$$y00008 Positron annihilation signal as a function of the position of the scraper target. The continuous curve represents a complementary error function fit with $\sigma=4.9$ mm. The dotted line is the corresponding beam profile.
002722395 8564_ $$82233320$$s8827$$uhttp://cds.cern.ch/record/2722395/files/figure8.png$$y00007 Slow positron yield of the GBAR positron source as a function of the linac frequency. Both the number of positrons per pulse (circles) and the number of positrons per second (positron flux) (triangles) are shown. The yield was measured after more than 30 minutes operation at a given frequency.
002722395 960__ $$a13
002722395 980__ $$aARTICLE