A large-area liquid scintillation counter and some measurements on high-energy cosmic-ray particles

Journal Article · Wed Jan 01 00:00:00 EST 1958 · Canadian Journal of Physics

DOI:https://doi.org/10.1139/p58-006· OSTI ID:4333994

Millar, C. H.; Hincks, E. P.; Hanna, G. C.

A liquid scintillation counter is described which consists of a 29 3/4 in. by 29 3/4 in. by 2 in. Plexiglas tank of terphenyl alpha - naphthylphenyloxazole ( alpha NPO) in triethylbenzene. The tank is surrounded by MgO powder and viewed by a total of eight RCA Type 5819 photomultiplier tubes along two opposite edges. For normally incident fast mu mesons a peaked pulse height distribution is observed, 20.5% in width at half maximum for the central area of the counter, broadening to 25 to 30% at the perimeter, and estimated to be 25% overall. When the Landau distribution in energy loss (width 18% at half- maximun) and the geometric spread are taken into account, a counter resolution function 8% in width at halfmaximum is obtained for the central area of the couater, or 18% for the counter as a whole. The most probable pulse height for 0.30 Bev mu mesons is 1.6 plus or minus 0.5% higher than for 2.2 Bev. μ - mesons, in close agreement with the Bethe -Bloch theory as extended by Symon amd with a density correction calculated by the method of Sternheimer. Pulse heights from protons in the region 0.3 to 0.8 Bev vary directly with the theoretically computed energy loss in the counter. Peak position and resolution are unchanged by a flux of 12 mr/hr of thorium gamma rays.

• Research Organization: Atomic Energy of Canada, Ltd., Chalk River, Ont.
• Sponsoring Organization: USDOE
• NSA Number: NSA-12-005427
• OSTI ID: 4333994
• Journal Information: Canadian Journal of Physics, Vol. 36, Issue 1; Other Information: Orig. Receipt Date: 31-DEC-58; ISSN 0008-4204
• Publisher: Canadian Science Publishing
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AROMATIC HYDROCARBONS
BACKGROUND
BENZENE
BETHE-BLOCH RELATION
CONFIGURATION
COSMIC RADIATION
DENSITY
ENERGY
ENERGY RANGE
ETHYL RADICALS
GAMMA RADIATION
GAMMA SOURCES
LANDAU DISTRIBUTION
LIQUIDS
LOSSES
MAGNESIUM OXIDES
MUONS
NUMERICALS
ORGANIC NITROGEN COMPOUNDS
PHENYL RADICALS
PHOTOMULTIPLIERS
PLEXIGLAS
POWDERS
PROTONS
PULSE ANALYZERS
PULSES
RADIATION DOSES
SCINTILLATION COUNTERS
TERPHENYLS
THORIUM