eprintid: 1498511 rev_number: 29 eprint_status: archive userid: 608 dir: disk0/01/49/85/11 datestamp: 2016-06-12 04:50:14 lastmod: 2021-10-04 01:04:52 status_changed: 2017-03-17 14:13:24 type: article metadata_visibility: show creators_name: Cooper, BS creators_name: Alonso, AM creators_name: Deller, A creators_name: Wall, TE creators_name: Cassidy, DB title: A trap-based pulsed positron beam optimised for positronium laser spectroscopy ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F60 keywords: Science & Technology, Technology, Physical Sciences, Instruments & Instrumentation, Physics, Applied, Physics, SLOW POSITRONS, ANNIHILATION LIFETIME, LOW-ENERGY, EXCITATION, SURFACES, ACCUMULATOR, TRANSITION, COLLISIONS, RADIATION, INTERVAL note: © 2015 AIP Publishing LLC. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in Cooper, BS; Alonso, AM; Deller, A; Wall, TE; Cassidy, DB; (2015) A trap-based pulsed positron beam optimised for positronium laser spectroscopy. Review of Scientific Instruments , 86 (10) , Article 103101 and may be found at http://doi.org/10.1063/1.4931690 abstract: We describe a pulsed positron beam that is optimised for positronium (Ps) laser-spectroscopy experiments. The system is based on a two-stage Surko-type buffer gas trap that produces 4 ns wide pulses containing up to 5 × 105 positrons at a rate of 0.5-10 Hz. By implanting positrons from the trap into a suitable target material, a dilute positronium gas with an initial density of the order of 107 cm−3 is created in vacuum. This is then probed with pulsed (ns) laser systems, where various Ps-laser interactions have been observed via changes in Ps annihilation rates using a fast gamma ray detector. We demonstrate the capabilities of the apparatus and detection methodology via the observation of Rydberg positronium atoms with principal quantum numbers ranging from 11 to 22 and the Stark broadening of the n = 2 → 11 transition in electric fields. date: 2015-10 date_type: published publisher: AMER INST PHYSICS official_url: http://doi.org/10.1063/1.4931690 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green article_type_text: Article verified: verified_manual elements_id: 1092964 doi: 10.1063/1.4931690 lyricists_name: Cassidy, David lyricists_name: Deller, Adam lyricists_id: DBCAS57 lyricists_id: AMDEL12 actors_name: Cassidy, David actors_name: Laslett, David actors_id: DBCAS57 actors_id: DLASL34 actors_role: owner actors_role: impersonator full_text_status: public publication: Review of Scientific Instruments volume: 86 number: 10 article_number: 103101 pages: 11 issn: 0034-6748 citation: Cooper, BS; Alonso, AM; Deller, A; Wall, TE; Cassidy, DB; (2015) A trap-based pulsed positron beam optimised for positronium laser spectroscopy. Review of Scientific Instruments , 86 (10) , Article 103101. 10.1063/1.4931690 <https://doi.org/10.1063/1.4931690>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1498511/1/Cassidy_1%252E4931690.pdf