Fig 1.
Schematic layout of the experimental setup.
Experimental setups for (a) Rayleigh scattering measurements and (b) ion time-of-flight measurements from laser-cluster fusion plasmas. The same nozzle was used for both measurements with an orifice diameter of d = 0.79 mm and an expansion half-angle of α = 5°.
Fig 2.
Time-averaged and time-resolved Rayleigh scattering signals.
The red lines indicate time-resolved Rayleigh scattering signals from methane clusters produced at a backing pressure of 20 bar with a 1 ms valve opening time. The black bars indicate time-averaged signals during 10 μs intervals. The time-averaged signal reaches its peak around 800 μs with a full width at half maximum of ~700 μs.
Fig 3.
The pressure dependence of Rayleigh scattering signal intensity and the average radius of methane clusters.
(a) The Rayleigh scattering signal intensity and (b) the average radius of the methane clusters with respect to the backing pressure varying from 11 bar to 69 bar. Each data point represents a 15-shot average, and error bars are obtained from their standard deviations.
Fig 4.
Ion time-of-flight signal and the expected ion temperature.
(a) Ion time-of-flight signal from the MCP detector smoothed out with a Savitzky-Golay filter (SGF). The red curve shows a Maxwellian fit for deuterium ions with kT = 52 keV. (b) Expected ion temperature derived from average cluster radius with respect to the backing pressure. The blue diamond indicates the deuterium ion temperature (52±2 keV) measured from the MCP time-of-flight detector.