Charge Amplifiers for Bonner Multisphere Systems

Features

• Accurate measurements of ambient neutron spectra
• Optimization of the 0.5NH1/1KI detector, delivered as an option
• Very high count rate stabilization in long time periods
• Miniature isotropic 0.5NH1/1KI Helium-3 neutron detector
• Easy implementation of Bonner multispheres
• Light and performant devices, easy to transport and install

Description

The ACHMS98 charge amplifier has been developed in close collaboration with the French Atomic Energy Commission to facilitate and optimize the spectral analysis of neutron fields by using the T.W. Bonner multisphere method.

The very high amplifier gain allows for the use of the 0.5NH1/1KI miniature isotropic Helium-3 detector (please refer to 10 mm diameter neutron detectors data sheet) with very low gas amplification factors, ensuring the best PHA spectrum quality with a very distinct valley and thus high count rate stability. The measurement accuracy is then drastically improved.

The 0.5NH1/1KI detector (delivered as an option) is remarkeable due to its very small size (1 cm active length, 1 cm diameter), sensitivity (0.5 cps/nv) and isotropy which make it a unique detector on the market. Both characteristics and small dimensions allow for building a performant and easy to transport neutron spectrum analyser.

In order to facilitate on site installation, a rod placed on the upper part of the preamplier box allows for easy mounting or the optional neutron detector and the associated moderating polyethylene spheres (not delivered). A mechanical sturdy support ensures stable mounting of the whole device.