Neutron Emission From the Plasma Focus PF-24 Device Under Different ar Doping in Ar+D2 Mixtures–Experimentsand Simulations

The main goal of performed experiments and simulations was to investigate the neutron emission from plasma pinch at different Ar doping, compare the measured and computed neutron emission values and test the newly installed imaging system. The series of experiments were carried out in the recently constructed Mather-type Plasma Focus (dynamic Z- pinch) PF-24
¹
. The experiments were performed at 16.8 kJ of stored energy. The experimental chamber was filled with pure
$\mathrm{D}_{2}$
or pure Ar, or mixtures of
$\mathrm{D}_{2}+$
Ar under different Ar doping in 3-60% range and under constant total gas pressure. During all experiments three diagnostic systems: Rogowski coil
¹
, magnetic probe
¹
and beryllium activation counter
¹
, were used to register total discharge current trace, total discharge current derivative over time trace and total DD fusion neutron yield per discharge
$(Y_{n})$
, respectively. Furthermore, the newly installed 4 frame high speed imaging system 1 was used to register 2D plasma pinch cross-section images in VUV and SXR radiation during a few discharges. The registered
$Y_{n}$
deceased rapidly with increasing Ar content in
$\mathrm{D}_{2}+$
Ar mixture. All investigated discharges were simulated and fitted using the 5-phase Lee model code
²
, giving a set of parameters describing generated plasma in the PF-24. The
$Y_{n}$
was calculated from equation (implemented in the code) based on a plasma diode action and a beam-target interaction mechanism
³
. The good agreement between the experimental and computed
$Y_{n}$
was found.