Self-Powered Neutron Detectors SPND

The principle of signal generation in a self-powered detector is simple. As a result of bombardment by radiation, the emitter releases electrons (betas) that escape to the insulator and leave the emitter positively charged. If the emitter is connected to the collector through a resistor (Fig. 14.25), current flows, which 

Because self-powered detectors have been developed for use inside the core of power reactors, they are designed to have small size (a few millimeters in diameter), to be able to operate for rather long periods of time (years) in the intense radiation field of the reactor core without appreciable deterioration in performance, and finally, to operate without an external power supply. 

The performance of a self-powered detector is given in terms of its sensitivity 5, defined by the equation 

the sensitivity represents the change in detector current per unit change in the flux. 

Many elements have been considered as emitters for self-powered detectors. The ideal emitter should be such that the detector has 

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Self-powered neutron detectors (SPNDs) use a material such as cadmium that has a high cross section for low-energy neutrons and produces copious gammas or... 

This chapter discusses in detail all the neutron detection methods mentioned above, as well as the Bragg crystal spectrometer, the time-of-flight method, compensated ion chambers, and self-powered neutron detectors (SPND). Other specialized neutron detectors, such as fission track recorders and thermoluminescent dosimeters, are described in Chap. 16. 

Neutron-sensitive self-powered detectors with prompt response operate on a different principle than rhodium and vanadium SPNDs. The emitter, in this case, absorbs a neutron and emits gammas at the time of capture. It is these capture gammas that are responsible for the signal, and since they are only emitted at the time of the neutron capture, the detector response is instanta-... 

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