Plasma focus devices may arise as useful source to perform experiments aimed to study the effects of pulsed radiation on human cells in vitro. In the present work, a table top hundred joules plasma focus device, namely “PF-400J”, was adapted to irradiate colorectal cancer cell line, DLD-1. For pulsed x-rays, the doses (energy absorbed per unit mass, measured in Gy) were measured using thermoluminescence detectors (TLD-100 dosimeters). The neutron fluence and the average energy were used to estimate the pulsed neutron doses. Fifty pulses of x-rays (0.12 Gy) and fifty pulses of neutrons (3.5 μGy) were used to irradiate the cancer cells. Irradiation-induced DNA damage and cell death were assessed at different time points after irradiation. Cell death was observed using pulsed neutron irradiation, at ultralow doses. Our results indicate that the PF-400J can be used for in vitro assessment of the effect of pulsed radiation in cancer cell research.

The feasibility of inferring the plasma parameters of a Penning discharge in helium, from the experimentally observed intensities of a number of spectral lines in the visible wavelength region, is explored. The collisional-radiative model of ADAS (atomic data analysis structure) code and database has been used for this analysis. The electron density, electron temperature, ground-state atom and ion densities and also the 2 3 S metastable state density are the parameters thus estimated. The results are encouraging. The derived plasma parameters are then used to obtain the intensities of a few lines in the vacuum ultraviolet (VUV) region. This has been compared with the observed VUV spectral lines, recorded simultaneously with the visible lines, using a VUV spectrometer for which intensity calibration was not available, to arrive at calibration factors. It is expected that this approach might provide an alternative to the 'branching ratio' method for calibration in the VUV region once the analysis is improved and the possible re-absorption of certain lines is accounted for.

The correct modelling of velocity distribution functions for particles in steady-state plasmas is a central element in the study of nuclear fusion and also in the description of space plasmas. In this work, a statistical mechanical formalism for the description of collisionless plasmas in a steady state is presented, based solely on the application of the rules of probability and not relying on the concept of entropy. Beck and Cohen's superstatistical framework is recovered as a limiting case, and a "microscopic" definition of inverse temperature β is given. Non-extensivity is not invoked a priori but enters the picture only through the analysis of correlations between parts of the system.

The temporal correlation between neutron and hard X-ray (HXR) emissions from a hundred joules plasma focus device (PF-400J) was studied. A method, time history analysis, to estimate the time of origin of neutrons with respect to HXRs is applied. In most of the discharges, it was found that neutrons are originated before HXRs in the axial direction and after HXRs in the radial direction. In some discharges, the time difference between HXRs and neutrons origin was found large enough, so that it can be interpreted that those neutrons would have been originated before the pinch. A qualitative discussion is conjectured to explain the experimental observations.