Ludlum Model 42-31H

  Neutron Radiation Detector

●  Application: Neutron Radiation Survey

●  Detector: ³H Proportional

●  Detection Range: Thermal to approximately 12 MeV

●  Sensitivity: 100 cpm/mrem/hr (²⁴¹AmBe)

●  Gamma Rejection: ≤ 10 cpm through 10 R/hr

The Model 42-31H is a 9 in. REM ball type neutron radiation detector designed to be used with portable counting instruments.  It includes a top mounted bracket that facilitates mechanical connection directly to a portable instrument's case. It is designed for detection of thermal and fast neutrons (0.025 eV to approximately 12 MeV). The Model 42-31H detector consists of a ³He detector 0.63 diameter x 1 in. long (1.6 x 2.5 cm), surrounded by a cadmium-loaded polyethylene sphere, 9 in. (22.9 cm) in diameter. A study is available that shows that the 9-inch cadmium-loaded sphere has a response similar to that of a 10-inch diameter rem-responding sphere.
 

PART NUMBER: 4005-140

APPLICATION: neutron radiation survey

RADIATION DETECTOR: 2 Atm ³He tube LND 25185 or equivalent
Moderator: 9 in. (22.9 cm) diameter cadmium-loaded polyethylene sphere

Detection Range: thermal to approximately 12 MeV

Energy Response: thermal to 12 MeV, follows radiation protection guide curve for neutron dose
Sensitivity: typically 100 cpm/mrem/hr (1 cpm/mS/h) (²⁴¹AmBe fast neutrons)
Gamma Rejection: typically 10 cpm or less through 10 R/hr (0.1 Sv/hr) (¹³⁷Cs)
Input Sensitivity: -2 mV  
Compatible Instruments: typically used with portable counting instruments (capable of achieving -2 mV input sensitivity)
Operating Voltage: approximately 1200 volts  
Connector: series “C” (others available)
Temperature Range: -4 to 122 °F (-20 to 50 °C)
Size: 10.3 x 9.0 x 9.0 in. (26 x 22.9 x 22.9 cm) (H x W x D), including brackets

Weight: 14.5 lb (6.6 kg)

Data Sheet

Product Manual

CE Certificate