Further simulations of the gain in a K XIX/Cl XVII resonantly photopumped X-ray Laser

Al’Miev, I. R.; Rose, S. J.; Wark, J. S.

doi:10.1016/s0022-4073(00)00108-4

Cited by 4 publications

(3 citation statements)

References 24 publications

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“…3, any deviations from the ideal conditions, i.e., those at which enhancement peaks, will result in a reduction in enhancement. This reflects the requirement for a high population of He-like K and H-like Cl, a necessity for the pumping line to be optically thick, maximizing absorption, and yet low enough density that photopumping is not destroyed by collisional deexcitation [19]. This experiment, relying on long pulse heating of a finite size laser target, will be subject to spatial and temporal gradients in temperature and density.…”

Section: Fig 3 Contour Plot Showing Cretin Calculated Increases In mentioning

confidence: 99%

X-ray-line coincidence photopumping in a potassium-chlorine mixed plasma

et al. 2020

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Exploiting the multiple long pulse capability and suite of x-ray diagnostics of the Orion laser, we have set out to explore line coincidence photopuming-the enhancement in population of an atomic level brought on by resonant absorption of x rays from a different emitting ion. Unlike previous work, the two ions are in the same plasma and so the experiment is an x-ray analog of the well-known Bowen resonance fluorescence mechanism that operates in astrophysical situations in the optical region. Our measurements have shown enhanced fluorescence in a chlorine plasma, attributable to line coincident photopumping from co-mixed potassium ions. To detect this relatively low signal-to-noise phenomenon, the data from multiple shots are combined, and the statistical method of bootstrapping is used to assign a confidence value to the measured enhancement, resulting in an estimate of the enhancement of 39 ± 16 18 % compared to the null case, where no pumping occurs. The experimental results have been compared to coupled radiation-transport and radiation hydrodynamics simulations using the CRETIN code together with the NYM radiation hydrodynamics model and agreement has been found, with the simulations also predicting modest enhancement.

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Section: Fig 3 Contour Plot Showing Cretin Calculated Increases In mentioning

confidence: 99%

X-ray-line coincidence photopumping in a potassium-chlorine mixed plasma

et al. 2020

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“…R r a/b is the radiative rate from a to b. In addition to the rate equations X a Z a ðtÞn a ðtÞ ¼ n e (2) gives the total electron number density where Z a is the degree of ionisation (the number of ionised electrons arising from the ion in level a) where n e is the electron number density. In some cases where there is reason to believe that the populations have reached a steady-state then the problem can be simplified by solving equations (1) and (2) together with E-mail address: s.rose@imperial.ac.uk…”

Section: Population Kinetics Including a Radiation Fieldmentioning

confidence: 99%

“…However there has been much theoretical work on both the degree to which the two lines coincide (for example [1,27] and on the calculation of the operation of the scheme [20,21] and references contained therein). Possible reasons for this lack of experimental success include the differential Doppler shift between the pumping and pumped plasma and an overestimate of the brightness in the pumping line (possibly due to velocity gradients in the pumping plasma producing much larger effective line widths than have been assumed [2,3,6,[23][24][25]37,38]). Whilst not resulting in gain, other experiments have demonstrated direct photopumping of one plasma by another.…”

Section: Narrow-band Photopumpingmentioning

confidence: 99%