CERN Accelerating science

Article
Title	The ALPHA-2 apparatus - facilitating experimentation with trapped antihydrogen
Author(s)	Akbari, R (British Columbia U.) ; Alves, B X R (Aarhus U.) ; Baker, C J (Swansea U.) ; Baquero-Ruiz, M (LPHE, Lausanne) ; Bertsche, W (Cockcroft Inst. Accel. Sci. Tech. ; Manchester U.) ; Butler, E (CERN) ; Burrows, C (Swansea U.) ; Capra, A (TRIUMF) ; Cesar, C L (Rio de Janeiro Federal U.) ; Charlton, M (Swansea U.) ; Collister, R (TRIUMF) ; Cridland, A (Swansea U.) ; Eriksson, S (Swansea U.) ; Evans, A (Calgary U.) ; Evans, L T (UC, Berkeley) ; Evetts, N (British Columbia U.) ; Fajans, J (UC, Berkeley) ; Friesen, T (Aarhus U. ; Calgary U.) ; Fujiwara, M C (TRIUMF) ; Gill, D R (TRIUMF) ; Grandemange, P (TRIUMF ; Calgary U.) ; Granum, P (Aarhus U.) ; Gutierrez, A (British Columbia U.) ; Hangst, J S (Aarhus U.) ; Hayden, M E (Simon Fraser U.) ; Hodgkinson, D (UC, Berkeley ; Manchester U.) ; Isaac, C A (Swansea U.) ; Ishida, A (Tokyo U.) ; Johnson, M A (Cockcroft Inst. Accel. Sci. Tech. ; Manchester U.) ; Jones, J M (Swansea U.) ; Jones, S A (Swansea U. ; U. Groningen, VSI) ; Jonsell, S (Stockholm U. (main)) ; Khramov, A (TRIUMF) ; Kurchaninov, L (TRIUMF) ; Little, A (UC, Berkeley) ; Madsen, N (Swansea U.) ; Maxwell, D (Swansea U.) ; McKenna, J T K (TRIUMF) ; Menary, S (York U., Canada) ; Michan, J M (TRIUMF ; LPHE, Lausanne) ; Momose, T (British Columbia U.) ; Mullan, P S (Swansea U. ; Zurich, ETH) ; Olchanski, K (TRIUMF) ; Olin, A (TRIUMF ; Victoria U.) ; Peszka, J (Zurich, ETH ; Swansea U.) ; Povilus, A (LLNL, Livermore) ; Powell, A (Calgary U.) ; Pusa, P (Liverpool U.) ; Rasmussen, C Ø (Aarhus U. ; CERN) ; Sacramento, R L (Rio de Janeiro Federal U.) ; Sameed, M (Swansea U. ; Manchester U.) ; Sarid, E (Soreq Nucl. Res. Ctr. ; Ben Gurion U. of Negev) ; Silveira, D M (Rio de Janeiro Federal U.) ; So, C (TRIUMF ; Calgary U.) ; Stracka, S (Pisa U. ; INFN, Pisa) ; Stutter, G (Aarhus U.) ; Tharp, T D (Marquette U.) ; Thompson, R I (Calgary U.) ; Torkzaban, C (UC, Berkeley) ; van der Werf, D P (Swansea U.) ; Wurtele, J S (UC, Berkeley)
Publication	2025
Number of pages	24
In:	Nucl. Instrum. Methods Phys. Res., A 1072 (2025) 170194
DOI	10.1016/j.nima.2024.170194 (publication)
Subject category	Detectors and Experimental Techniques
Accelerator/Facility, Experiment	CERN ALPHA
Abstract	This paper describes the ALPHA-2 apparatus, used at the CERN Antiproton Decelerator facility for the study of trapped antihydrogen atoms. Details of both the construction and performance are included. Prominence is given to both the new and the improved features, with respect to the original ALPHA assembly, of the apparatus including a stand-alone antiproton catching trap, the traps used to mix antiparticles to produce the anti-atoms, the magnetic atom trap used to hold some of them, and access for laser light to facilitate excitation of the antihydrogen 1S-2P and 1S-2S transitions.
Copyright/License	publication: © 2025 The Authors (License: CC BY 4.0)

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