Interferometric method for monitoring the amount of gas in laser fusion targets

The structure connectivity factor as applied to the determination of the hydrogen permeability coefficient of glasses

“…In [31], the gas pressure in a microsphere was measured by the interference method and the hydrogen permeability coefficient K H was calculated with allowance made for the shift ∆N 1,2 in the interference fringes; that is, By measuring the half-release time for gas in days and the quantities r and h in micrometers (Table 3), it is easy to demonstrate that the hydrogen permeability coefficient K H is described by the formula (1) which, however, does not take into account the glass composition.…”

“…Veselov et al [31] calculated the hydrogen permeability coefficient K H from the formula where r is the inside microsphere radius (m); h is the microsphere wall thickness (m); T is the temperature (K); ∆t is the time of filling of a microsphere with a DT gas (s); P 0 and P are the internal and external pressures (Pa) in the course of filling, respectively; and R is the gas constant.…”

Target technology development for the research of high energy density physics and inertial fusion at the RFNC–VNIIEF

“…(1) and (2) are presented. The values of pressure obtained experimentally by the method of optical interferometry (Veselov et al, 1981) are here given. The values of pressure obtained experimentally by the method of optical interferometry (Veselov et al, 1981) are here given.…”

Non-destructive method for measuring the D2/DT fill pressure and permeability for direct drive plastic shells

“…The fill pressure of diffusion filled direct drive plastic implosion targets is generally not accurately known, for two major reasons: (1) There is no practical, non-destructive and generally applicable (i.e. valid for both low and high pressure fills) method of measuring the internal pressure after filling.…”

“…valid for both low and high pressure fills) method of measuring the internal pressure after filling. Interferometric methods, such as that discussed by Veselov et al [1] work well for targets with thin walls and/or high pressure fill. For thick walled targets or for targets with low pressure fill, the accuracy of the interferometric method is often unacceptable.…”