Performance of a plasma window for a high pressure differentially pumped deuterium gas target for mono-energetic fast neutron production - Preliminary results

The reactions D(d,n)He-3 and T(d,n)He-4 are frequently used for production of the mono-energetic or quasi monoenergetic neutron beams but successful a pplications are often limited by the intensity of the generated neutron bea ms. The development of a suitable neutron source for such applications as s tudies of resonance phenomena, fast neutron radiography, selective fast neu tron activation, explosives and contraband detection and others, depends on the output ion current of the accelerator and the design of the target sys tem. A practical solution for a high pressure gas target was previously dev eloped and successfully implemented at De Beers Diamond Research Laboratory in Johannesburg (Guzek et al., 1999), but it is limited to applications us ing low (<20%) duty cycle accelerators. The concept of a plasma window for the separation of a high pressure gas target region and accelerator vacuum, that was originally developed by Hershcovitch (1995) for electron welding applications, may be suitable for operation with continuous wave accelerato rs at high particle current output. Preliminary test results, which have be en performed with various gases (argon, helium and deuterium), indicate tha t implementation of the plasma window into a gas target system, for the pro duction of intense mono-energetic fast neutron beams will be achievable. (C ) 2000 Elsevier Science B.V. All rights reserved.