Electron Beam Properties Emitted From Deuterium Plasma Focus: Scaling Laws

The Lee model is extended to study and characterize the electron beams emitted from plasma-focus devices. It is then first applied to characterize the electron beams emitted from low and high-energy plasma focus operated with deuterium gas. The numerical experiments on NX2 device at 15 torr of deuterium give the following results: electron fluence = 5.7 x 10(22) m(-2), electron flux = 16 x 10(29) m(-2) s(-1), the relativistic kinetic mean energy of the electron = 56 keV, electron number = 2 x 10(16), electron current = 91 kA, and damage factor = 2.7 x 10(12) W . m(-2)s(0.5). Then, the effect of pressure on the beam characteristics is studied. The energy of the beam at pinch exit changes from around 57 J (1.9% of the stored energy E-0) to 176 J (6% E-0) with maximum value of 180 J (6.1% E-0) at 15 torr, and these results are compared with the measured values 3.2% E-0 on NX2. Scaling trends are suggested for electron beam characteristics. The energy fluence and the power flow density (energy flux) have a variation 4.3 - 265 x 10(7) J . m(-2) and 2.2 - 19 x 10(15) W . m(-2), respectively. The electron beam current ranges from 12 to 700 kA being 9%-35% of I-peak. The energy beam Y-EB scales on average as Y-EB = 6.55 x E-0(1.45) at energies in the 1 to 500 kJ regions (Y-EB in J and E-0 in kJ), and YEB = 1 x 10(-6) I-pinch(3.53) and Y-EB = 2 x 10(-6) I-peak(3.14) (I-peak and I-pinch in kA and Y-EB in J). These results provide much needed benchmark reference values and scaling trends for electron beams of a plasma focus operated in deuterium gas.