Atomic collision experiment using ultra-slow antiproton beams

Hiroyuki A. Torii, N. Kuroda, M. Shibata, H. Imao, Y. Nagata, D. Barna, M. Hori, Y. Kanai, A. Mohri, V. L. Varentsov, Y. Yamazaki

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The development of techniques to decelerate, cool and confine antiprotons in vacuo with an electromagnetic trap has opened a new research field of atomic physics of 'cold' antiprotons, including synthesis of antihydrogen atoms. At the Antiproton Decelerator (AD) facility at CERN, we the MUSASHI group of ASACUSA collaboration have so far achieved efficient confinement of millions of antiprotons in a Multi-Ring electrode Trap (MRT) installed in a superconducting magnet of 2.5 T, by a sequential combination of the AD (down to 5.3 MeV), an RFQD (Radio-Frequency Quadrupole Decelerator; down to 50-120 keV) and the MRT. Antiprotons, cooled to energies less than an electronvolt by preloaded electrons in the trap, was then extracted out of the magnetic field and transported along a 3-m beamline as a monoenergetic beam of 10-500 eV. With this unique ultra-low-energy antiproton beam, we are now planning the first atomic collision experiments under single collision conditions, to measure ionization and atomic capture cross sections of antiprotons against helium atoms. A supersonic atomic gas-jet target is prepared and crossed with the antiproton beam. Antiprotons as well as electrons emitted during the reaction will be detected by a microchannel plate (MCP) while the antiproton annihilation will be recognized by detection of annihilation products - mostly pions - by surrounding scintillation counters. When the antiproton is captured, it forms a neutral antiprotonic helium atom, some in a metastable state whose level structures have been well studied with spectroscopic methods. Severe identification of particles and atoms plays an essential role in the design of the experiment, to distinguish the small number of reaction events out of a huge pile of background events. Our strategies for our near-future experiments are discussed.

Original languageEnglish
Article number012022
JournalJournal of Physics: Conference Series
Volume80
Issue number1
DOIs
Publication statusPublished - Sep 1 2007

Fingerprint

atomic collisions
antiprotons
brakes (for arresting motion)
traps
helium atoms
gas jets
electrodes
atomic physics
microchannel plates
monatomic gases
rings
superconducting magnets
piles
neutral atoms
metastable state
absorption cross sections
scintillation counters
atoms
planning
radio frequencies

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Torii, H. A., Kuroda, N., Shibata, M., Imao, H., Nagata, Y., Barna, D., ... Yamazaki, Y. (2007). Atomic collision experiment using ultra-slow antiproton beams. Journal of Physics: Conference Series, 80(1), [012022]. https://doi.org/10.1088/1742-6596/80/1/012022

Atomic collision experiment using ultra-slow antiproton beams. / Torii, Hiroyuki A.; Kuroda, N.; Shibata, M.; Imao, H.; Nagata, Y.; Barna, D.; Hori, M.; Kanai, Y.; Mohri, A.; Varentsov, V. L.; Yamazaki, Y.

In: Journal of Physics: Conference Series, Vol. 80, No. 1, 012022, 01.09.2007.

Research output: Contribution to journalArticle

Torii, HA, Kuroda, N, Shibata, M, Imao, H, Nagata, Y, Barna, D, Hori, M, Kanai, Y, Mohri, A, Varentsov, VL & Yamazaki, Y 2007, 'Atomic collision experiment using ultra-slow antiproton beams', Journal of Physics: Conference Series, vol. 80, no. 1, 012022. https://doi.org/10.1088/1742-6596/80/1/012022
Torii, Hiroyuki A. ; Kuroda, N. ; Shibata, M. ; Imao, H. ; Nagata, Y. ; Barna, D. ; Hori, M. ; Kanai, Y. ; Mohri, A. ; Varentsov, V. L. ; Yamazaki, Y. / Atomic collision experiment using ultra-slow antiproton beams. In: Journal of Physics: Conference Series. 2007 ; Vol. 80, No. 1.
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