eprintid: 1362267 rev_number: 30 eprint_status: archive userid: 608 dir: disk0/01/36/22/67 datestamp: 2012-09-15 18:54:24 lastmod: 2021-09-20 00:34:43 status_changed: 2012-09-15 18:54:24 type: article metadata_visibility: show item_issues_count: 0 creators_name: Cassidy, DB creators_name: Deng, SHM creators_name: Tanaka, HKM creators_name: Mills, AP creators_name: Greaves, RG creators_name: Maruo, T creators_name: Nishiyama, N creators_name: Snyder, JB title: Experiments with a high-density positronium gas ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F60 note: © 2005 The American Physical Society abstract: We have created a high-density gas of interacting positronium (Ps) atoms by irradiating a thin film of nanoporous silica with intense positron bursts and measured the Ps lifetime using a new single-shot technique. When the positrons were compressed to 3.3×1010cm-2, the apparent intensity of the orthopositronium lifetime component was found to decrease by 33%. We believe this is due to a combination of spin exchange quenching and Ps2 molecule formation associated with colliding pairs of oppositely polarized triplet positronium atoms. Our data imply an effective cross section for this process of 2.9×10-14cm-2. © 2005 The American Physical Society. date: 2005-11-04 official_url: http://dx.doi.org/10.1103/PhysRevLett.107.191802 vfaculties: VMPS oa_status: green primo: open primo_central: open_green verified: verified_manual elements_source: Scopus elements_id: 440105 doi: 10.1103/PhysRevLett.95.195006 lyricists_name: Cassidy, David lyricists_id: DBCAS57 full_text_status: public publication: Physical Review Letters volume: 95 number: 19 article_number: 195006 issn: 0031-9007 citation: Cassidy, DB; Deng, SHM; Tanaka, HKM; Mills, AP; Greaves, RG; Maruo, T; Nishiyama, N; Cassidy, DB; Deng, SHM; Tanaka, HKM; Mills, AP; Greaves, RG; Maruo, T; Nishiyama, N; Snyder, JB; - view fewer <#> (2005) Experiments with a high-density positronium gas. Physical Review Letters , 95 (19) , Article 195006. 10.1103/PhysRevLett.95.195006 <https://doi.org/10.1103/PhysRevLett.95.195006>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1362267/1/1362267.pdf