Instruction Manual

Featuring:

radiation monitoring

systems

A Mirion Technologies Division

SPN DETECTORS

Neutron Flux Instrumentation

SPN DETECTORS

Self-Powered Neutron Detectors

SPN-detectors are designed for the detection of

thermal neutrons within the core of the reactor. These

detectors generate a current proportional to the

neutron  ux density without applying an external

voltage source.

In general, the detector current of these detectors is

caused by the emission of beta radiation (electrons)

from the target material which gets activated by

neutrons. Therefore, besides the name SPN-detector

(Self-Powered Neutron detector), also the name n,ß-

detector (neutron-beta-detector) is in use.

APPLICATIONS

• Operational process monitoring

○ Detection and measurement of the thermal

neutrons inside the reactor core for neutron  ux

distribution monitoring and monitoring of neutron

 ux peaks

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SPN DETECTORS Neutron Flux Instrumentation SPN DETECTORS Self-Powered Neutron Detectors SPN-detectors are designed for the detection of thermal neutrons within the core of the reactor. These detectors generate a current proportional to the neutron flux density without applying an external voltage source. In general, the detector current of these detectors is caused by the emission of beta radiation (electrons) from the target material which gets activated by neutrons.
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SPN DETECTORS Neutron Flux Instrumentation PREFERRED TYPES OF THE IST-PROGRAM Notice: 1 nv = 1/cm2s Type Emitter Material Neutron Sensitivity (A/nv) Gamma Background Measuring Range (nv) Response Time (s) Detector Length L1 (mm) Total Length L2 (mm) WL-23215 Rhodium 1.0e-20 2% 1e9 ... 1e15 60 76 8 543 WL-23226 WL-23283 Vanadium Cobalt 1.1e-20 1.4e-21 2% 5% 1e9 ... 1e15 1e10...1e15 300 1e-10 1.321 864 9 144 4 877 COMMON DATA ● ● ● ● Operating temperature: 400°C max.