(a) Picture of the compact cryogenic droplet injector (see the text). (b) Enlarged view of the exit end evidencing the outer glass tube, which has an exit hole diameter of 140 μm, and the central inner capillary.
Stroboscopic images of periodic (a) argon and (b) hydrogen droplet beams propagating in vacuum. The argon beam is produced from a 10 ± 0.5 μm diameter capillary orifice at a nominal stagnation source pressure of 10 bars and at a temperature of 86 K and expanding in argon gas at a mass flow of 35 SCCM. The hydrogen beam is produced from a 5 ± 0.5 μm diameter capillary orifice at a nominal stagnation source pressure of 7 bars and at a temperature of 14.5 K expanding in hydrogen gas at 70 SCCM.
Relative mean droplet displacement determined from several single-shot stroboscopic images plotted as a function of the distance from the outer tube exit hole. The filled symbols are for argon (squares) and hydrogen (circles) beams, respectively, expanding in a co-flowing gas. The open symbols are for a hydrogen droplet beam produced without external gas atmosphere.
(a) Focal laser intensity distribution. The dashed circle indicates the 21 μm diameter argon droplet. (b) Time-integrated XUV image of the droplet thermal emission. The laser pulse comes from the left. (c) X-ray emission spectrum showing the strong argon K-α and He-α transition lines. The K-shell transitions in intermediate charge state argon ions are visible as satellites between the K-α and He-α lines.
Article metrics loading...
Full text loading...