Large-area proportional counter camera for the US National Small-Angle Neutron Scattering Facility

Conference · Tue Jan 01 04:00:00 EST 1980

OSTI ID:5804859

Abele, R K; Allin, G W; Clay, W T; Fowler, C E; Kopp, M K

An engineering model of a multiwire position-sensitive proportional-counter (PSPC) was developed, tested, and installed at the US National Small-Angle Neutron Scattering Facility at ORNL. The PSPC is based on the RC-encoding and time-difference decoding method to measure the spatial coordinates of the interaction loci of individual scattered neutrons. The active area of the PSPC is 65 cm x 65 cm, and the active depth is 3.6 cm. The spatial uncertainty in both coordinates is approx. 1.0 cm (fwhm) for thermal neutrons; thus, a matrix of 64 x 64 picture elements is resolved. The count rate capability for randomly detected neutrons is 10/sup 4/ counts per second, with < 3% coincidence loss. The PSPC gas composition is 63% /sup 3/He, 32% Xe, and 5% CO/sub 2/ at an absolute pressure of approx. 3 x 10/sup 5/ Pa (3 atm). The detection efficiency is approx. 90% for the 0.475-nm (4.75-A) neutrons used in the scattering experiments.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5804859
• Report Number(s): CONF-801103-66; ON: DE82003867
• Country of Publication: United States
• Language: English

Related Subjects

440101* -- Radiation Instrumentation-- General Detectors or Monitors &amp; Radiometric Instruments
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
MEASURING INSTRUMENTS
MULTIWIRE PROPORTIONAL CHAMBERS
PERFORMANCE TESTING
PROPORTIONAL COUNTERS
RADIATION DETECTORS
SPECIFICATIONS
TEST FACILITIES
TESTING