D-D neutron energy ~2.5 MeV
D-T neutron energy ~14 MeV
Development tests were conducted in a laboratory of the Physics Department of the University of Liverpool. An output neutron flux dosage equivalent to a point source strength of ~1 x 107 n/s was a preliminary measurement. Increasing the input power of the reaction chamber increases the neutron output. However, there are engineering limits associated with the electrode temperature and heat dissipation. Measurements in the laboratory of the Mannheim University of Applied Sciences used thermal neutron counting methods to verify the neutron output. Two different neutron area dosimeters measured the neutron field at distances ranging from 1 to 2m of the NSD GRADEL FUSION neutron generator fitted with a short electrode. Result: dosage measurements were similar. With the assistance of Dr. Klett of Berthold Technologies, the calibration data of a LB 6411 Neutron Probe was used to determine the neutron source emission rate at a reference voltage and current. A customer has also performed neutron flux measurements using a different thermal neutron detection and counting method. Secondary or scattered neutrons from the surrounding walls, ceiling and floor were shielded from the detector such that the flux was mostly from the direction of the neutron generator. A crane was used to suspend the neutron generator above a table in order to minimise effects of surrounding structures. These measurements were in good agreement with the neutron dosimeters. In both measurement campaigns, a reference 252Cf source was available.
Neutron Flux Distribution
A near field survey will be conducted when yield has been maximized.
Longer tests over several days were conducted during a demonstration of PGNAA by Dr. A. Nordlund of Chalmers University, Nuclear Engineering. The short electrode DD neutron generator was operated at 1x106 n/s using a cycle of 5 minutes on, their changes the moderator test set-up, another 5 minutes on and so on with excellent repetition. After a running-in or initial conditioning phase, the output is very stable and repeatable. An improved (high temperature) electrode was operated at the Hochschule Mannheim, University of Applied Sciences, Department of Chemical Engineering and Process Engineering, Radiochemistry Insitute of Prof. Dr. Erich Fosshag. This DD unit has been operated at up to 8 x 106 n/s with a very smooth, stable, and repeatable output; even in the semi-automated mode.
The automated neutron generator can be operated in pulsed mode (to 2kHz).
It has a rise time of ~1µsec and falltime neutron pulses with very low jitter (based on comparison of other neutron generators)
The first pulsed NSD-35-P neutron generator was delivered to the University of Sheffield.
More current performance information please refer to the data sheets of our sources. These are located in the area of products and are easy to download from our pdf generator