|
Schafer's PHILDEX-laser is a new scheme which consists in a cylinder-optical concentration of a short excimer laser pulse irradiating the high-Z coating of a cylindrical solid core of length £ and radius r. The pulse moves like a boots trap along the coating with nearly the speed of light. After 50% of the laser radiation is converted to X-radiation in the coating, this photo-ionizes preferentially the electrons in the lowest level of the core material. If nearly complete depletion with an atomic density n*(inverted states) is reached, the electrons at the energetically next higher level will decay to the lower level. For £» r, the preferential direction of the emitted superradiance along the axis will produce an X-ray laser pulse. For this laser some estimations are reported about the following properties: the line shift by recoil in the core which was assumed to be an instantly produced plasma where no Mossbauer-recoil is permitted. This is combined with the Doppler shift of the ionic motions. The overlapping of lines is found sufficient for the laser. An estimation of the necessary inversion density and the geometry of the medium are given. For the then necessary minimum core length of lmm, laser pulses in the order of 100 J are necessary with duration of less than 3 psec, preferably less.
|
