Some Approaches to Vacuum Uv and X-Ray Lasers

Abstract

The ejection of electrons from inner shells of atoms through photoionization is suggested as a straightforward means of creating population inversions at vacuum uv and x-ray wavelengths. This can be accomplished by photon sources covering broad bands. Sodium vapor and solid copper are examined as possible candidates for laser action at 372 Å and 1.54 Å, respectively. A first-rise traveling wave pump must be used; pumping powers required for superradiant operation run into several gigawatts, with rise times ranging from 10−9 sec in the near-vacuum uv to 10−15 sec in the x-ray region.

Transient-gain photoionization x-ray laser

“…X-ray lasers (XRLs) were first proposed in the 1960s [3], and since then, different pumping schemes have been studied in theory and experiment [4][5][6], which led to the first demonstrations of laboratory x-ray lasers in 1984 [7,8]. The photoionization inner-shell x-ray laser scheme was originally proposed by Duguay and Rentzepis [3], and since then, several possible targets and pumping schemes were studied in theory [9][10][11][12][13][14][15][16].…”

Atomic inner-shell radiation seeded free-electron lasers

“…This scheme was proposed as early as 50 years ago [27], but has not been experimentally implemented due to the lack of a suitable x-ray pump source. The introduction of XFEL makes it possible to pump new atomic inner-shell XRL.…”

Lasers in the vacuum ultraviolet and in the X-ray regions of the spectrum

“…В работе 18 была приведена оценка мощности, необходимой для достижения усиления характеристического излучения в Na и Си в режиме бугущей волны. В слу-чае Na рассматривался переход дырки £ И1 -> Μι (λ-372 А), в котором спонтанное время жизни верхнего уровня составляло величину τ 8 =4·10~1 0 сек.…”