A PROTO-TYPE LIQUID SCINTILLATION COUNTER USING CURRENT MODE IMPEDANCE MATCHING FOR LOW ENERGY BETA COUNTING (in Japanese)
A prototype liquid scintillation counter was made for naeasuring H/sup 3/ and C/sup 14/ activities using current mode impedance matching circuitry. This instrument is capable of counttng by four sizes of sample vial, 20, 50, 100, and 150 ml. The detector assembly consists of two high signalto-noise ratio photomultiplier tubes which are mounted at right angles and shielded from external radiation by 2" thick lead shields. Current pulses from each detector are fed into the fast coincidence circuit to reduce the thermal noise of the photomultiplier tubes, and for eliminating the high energy pulses, its output pulses are anticoincidenced with the pulses that exceed the upper level discriminator. The photomultiplier tubes, reflector material of a counting celi, and counting vial material are selected experimentally, because these problems are vital points in improving this instrument. It is concluded that this instrument can operate satisfactorily at room temperature, and the lower K/sup 40/ glass vial gave 1.5 times the background count of the quartz one. Typical results of measuring H/sup 3/ and C/sup 14/ samples using toluene-H/sup 3/ and benzoic-C/sup 14/ acid respectively, at room temperature (18.0, 0.5 deg C) are given in a table. The composition of scintillator was 4 g/l of PPO, 50 mg/l of POPOP in air-saturated toluene. Operating voltage is fixed at the balance point that gives maximum count at the various window- widths. (JAIP)
- Research Organization:
- Atomic Energy Div., Kobe Kogyo Corp.
- NSA Number:
- NSA-17-030100
- OSTI ID:
- 4699013
- Journal Information:
- Proc. Japan Conf. Radioisotopes, Journal Name: Proc. Japan Conf. Radioisotopes Vol. Vol: 5th, No. 3
- Country of Publication:
- Country unknown/Code not available
- Language:
- Japanese
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Related Subjects
BACKGROUND
BENZOIC ACID
BETA PARTICLES
CARBON 14
CIRCUITS
COINCIDENCE METHODS
ELECTRIC POTENTIAL
GENERAL AND MISCELLANEOUS
GLASS
LEAD
LIQUIDS
PHOTOMULTIPLIERS
POTASSIUM 40
PULSE ANALYZERS
PULSES
QUARTZ
RADIOACTIVITY
REFLECTION
SCINTILLATION COUNTERS
SCINTILLATIONS
SHIELDING
SIGNALS
TABLES
TOLUENE
TRITIUM