Neutron anisotropy measurements in dense plasma focus device by means of deuteron beam obstacle

The deuterium-deuterium (DD) fusion neutron yield and its anisotropy were measured for the NX2 plasma focus (PF) device by using two compact beryllium fast neutron activation detectors (designed and implemented by the authors) at 0° and 90° to the PF axis. The contribution to the fusion yield produced by the accelerated deuteron beam emitted from the hot plasma pinch was investigated by applying a circular Pyrex plate to obstruct the beam and suppress its fusion contribution. Neutron measurements were performed with the obstacle positioned at distances of 3 cm and 6 cm from the anode tip, and also without the obstacle for comparison. It is found that about 80% of the fusion reaction is occurring at vicinity of the plasma pinch. The results are compared with the proton fusion source images obtained by bright and high resolution technique, coded aperture imaging.