Demonstration of neutron production in a table-top pinch plasma focus device operating at only tens of joules

Abstract

Neutron emission from a deuterium plasma pinch generated in a very small plasma focus (6 mm anode diameter) operating at only tens of joules is presented. A maximum current of 50 kA is achieved 140 ns after the beginning of the discharge, when the device is charged at 50 J (160 nF capacitor bank, 38 nH, 20–30 kV, 32–72 J). Although the stored energy is very low, the estimated energy density in the plasma and the energy per particle in the plasma are of the same order as in higher energy devices. The dependence of the neutron yield on the filling pressure of deuterium was obtained for discharges with 50 and 67 J stored in the capacitor bank. Neutrons were measured by means of a system based on a 3He proportional counter in current mode. The average neutron yield for 50 J discharges at 6 mbar was (1.2 ± 0.5) × 104 neutrons per shot, and (3.6 ± 1.6) × 104 for 67 J discharges at 9 mbar. The maximum energy of the neutrons was (2.7 ± 1.8) MeV. Possible applications related to substance detection and others are discussed.

Dynamics and Density Measurements in a Small Plasma Focus of Tens-of-Joules-Emitting Neutrons

“…(with I p in kiloamperes) [5], [7]. The latter observation motivates future experiments in order to determine the contribution of Y th and Y b−t to the total neutron yield and to corroborate this preliminary scaling law for the region of hundreds and tens of joules.…”

“…In any case, it is interesting to research how to scale the neutron yield for devices operating at energies lower than 1 kJ. From results obtained in devices operating at E and I p of 400 J and 127 kA [12], 67 J and 60 kA [5], and 50 J and 50 kA [5], respectively, the following scaling has been observed: Y ∼ 7.73 × 10 −5 I…”

“…More recent studies have demonstrated neutron production when operating with deuterium at 50 and 67 J of stored energy in the capacitor bank. Average yields of 1.2 ± 0.5 × 10 4 neutrons/shot at 6 mbar and 50 J and 3.6 ± 1.6 × 10 4 neutrons/shot at 9 mbar and 67 J have been measured [5] using a detection technique based on 3 He-filled proportional counters specially adapted for pulsed neutron sources of low production [6]. It has been observed that the energy of the fast neutrons has a mean value of 2.7 MeV with a standard deviation of 1.8 MeV, the latter obtained using the time-of-flight technique [5].…”

Electromagnetic Burst Measurement System Based on Low Cost UHF Dipole Antenna

“…These self-scale plasma devices can generate neutron pulses [2][3][4], work as a pulsed X-ray source [5], produce plasma shocks [6], supersonic plasma jets [7], plasma filamentation [8], scaled astrophysical experiments [7] and they can also be used as a source to test new materials for the first wall of future fusion devices [9].…”

Potentiality of a table top plasma focus as X-ray source: Radiographic applications

“…However, this kind of sources has the technical disadvantage of the repetition regime, unlike to the performance that could have a plasma focus device, especially those of low energy. Radiographic applications using dense transient PF devices operating at some kJ or greater energy have been obtained in several laboratories in both biological radiography [5,6] and introspective radiography of non-biological objects [7,8] [3,[9][10][11][12][13][14][15][16]. Another advantage that favors the development of small plasma focus devices is the scaling observed in the dimensions of the pinch [17].…”