Delta electron production and the ultimate energy resolution of liquid argon ionization detectors

Conference · Mon Feb 01 00:00:00 EST 1988 · IEEE Trans. Nucl. Sci.; (United States)

OSTI ID:6996530

Aprile, E; Ku, W H.M.; Park, J

The calculated Fano factor limits the energy resolution in liquid argon ionization chambers to 4 keV (FWHM) at 1 MeV. This theoretical value is several times better than any experimental result reported so far in the literature. The authors have recently measured an intrinsic energy resolution of 26 +- 2 keV for the 976 KeV conversion electrons of a /sup 207/Bi source in a gridded ionization chamber filled with pure liquid argon, at a drift field of 11 kV cm/sup -1/. The measurement of the /sup 207/Bi spectrum at different electric fields was repeated several times, with very good liquid purity and optimized chamber geometry, reproducing the results. Data were also taken with a xenon-doped liquid argon filling in an attempt to improve the resolution. Enhanced ionization was observed as expected from the presence of excitons in liquid argon, but no improvement in the energy resolution. In this paper the authors show that the data are consistent with the assumption that recombination straggling from low energy delta electrons, produced abundantly along the path of the primary ionizing particle, is mostly responsible for the degraded experimental resolution.

• Research Organization: Columbia Astrophysics Lab., Columbia Univ., 538 West 120th Street, New York, NY (US)
• OSTI ID: 6996530
• Report Number(s): CONF-871006-; TRN: 88-025878
• Journal Information: IEEE Trans. Nucl. Sci.; (United States), Vol. 35:1; Conference: 34. nuclear science symposium and 19. nuclear power systems symposium, San Francisco, CA, USA, 21 Oct 1987
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
LIQUID IONIZATION CHAMBERS
ENERGY RESOLUTION
FANO FACTOR
PARTICLE PRODUCTION
ARGON
BISMUTH 207
CORRELATIONS
ELECTRIC FIELDS
ELECTRONS
IONIZATION
KEV RANGE 10-100
KEV RANGE 100-1000
QUANTUM FLUIDS
RECOMBINATION
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BISMUTH ISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
FERMIONS
FLUIDS
GASES
HEAVY NUCLEI
IONIZATION CHAMBERS
ISOTOPES
KEV RANGE
LEPTONS
MEASURING INSTRUMENTS
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
RADIATION DETECTORS
RADIOISOTOPES
RARE GASES
RESOLUTION
YEARS LIVING RADIOISOTOPES
440104* - Radiation Instrumentation- High Energy Physics Instrumentation