Very Long Lasers

Linford, Gary J.; Peressini, E. R.; Sooy, W. R.; Spaeth, M. L.

doi:10.1364/ao.13.000379

Cited by 270 publications

(71 citation statements)

References 10 publications

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“…5 Applying the Linford equation to the traveling wave data points indicates that the gain is as high as 65 cm -1 , as shown by the solid line through data points for 0.2 to 0.3 cm. 11 The second interesting feature relates to the observed trend in the x-ray laser output when the long pulse energy is set between approximately 0.7 and 2.2 J. It should be noted that the delay between the laser pulses and the short pulse energy were maintained constant.…”

Section: Resultsmentioning

confidence: 95%

Tabletop transient collisional excitation x-ray lasers

Dunn

Osterheld

et al. 1999

SPIE Proceedings

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Recent transient collisional excitation x-ray laser experiments are reported using the COMET tabletop laser driver at the Lawrence Livermore National Laboratory (LLNL). Ne-like and Ni-like ion x-ray laser schemes have been investigated with a combination of long 600 ps and short ~1 ps high power laser pulses with 5 -10 J total energy. We show small signal gain saturation for x-ray lasers when a reflection echelon traveling wave geometry is utilized. A gain length product of 18 has been achieved for the Ni-like Pd 4d→4p J=0-1 line at 147 Å, with an estimated output of ~10µJ. Strong lasing on the 119 Å Ni-like Sn line has also been observed. To our knowledge this is the first time gain saturation has been achieved on a tabletop laser driven scheme and is the shortest wavelength tabletop x-ray laser demonstrated to date. In addition, we present preliminary results of the characterization of the line focus uniformity for a Ne-like ion scheme using L-shell spectroscopy.

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Section: Resultsmentioning

confidence: 95%

Tabletop transient collisional excitation x-ray lasers

Dunn

Osterheld

et al. 1999

SPIE Proceedings

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“…The lifetime of the upper level, taking into account the radiative decay (without considering collisional processes) in Ne-like Ar +8 , is ≈100 ps (see Figure 1). Table 1 shows the gain due to the collisional excitation calculated by fitting the Linford formula [14] to the experimental data. It shows that the highest gain coefficient is 18.7 cm −1 , achieved in the case of plasma driven with double-short pulses [10].…”

Section: +8mentioning

confidence: 99%

“…Taking into account Equation (14), the pumping time to the upper (t pum2 ) and lower level (t pum1 ) and the relaxation time from the upper level (t rel2 ) and lower level (t rel1 ) can be calculated.…”

Section: Pumping and Relaxation Timementioning

confidence: 99%

Optimum Pump Pulse Duration for X-Ray Ar-Plasma Lasing

Masoudnia

Bleiner

2015

Photonics

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In plasma-driven X-ray lasers, it is critical to optimize the duration and time delay between pump pulses. In this study, we have done parametric simulations in order to systematically investigate the optimum time configuration of pump pulses. Here, we are mainly interested in soft X-ray lasers created using a Ar target irradiated with laser pulses, which operate at a wavelength λ = 46.9 nm in the 2p 5 3p 1 (J = 0) → 2p 5 3s 1 (J = 1) laser transition. It is shown that the optimum time scale required to achieve Ne-like ions, as well as the time required to generate a population inversion depend on the combined effect of the electron temperature and electron density. The electron density and temperature are respectively a factor of ≈2.1-and ≈5-times higher in the case of a short pulse of 0.1 ps in comparison to a long pulse of 1,000 ps (at a constant fluence). The most effective lasing happens with short pulses with a pulse duration comparable to the total relaxation time from the upper level, namely ∆τ p ≤ 35 ps. Power laws to predict the optimum laser intensity to achieve Ne-like Ar +8 are obtained.

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“…7 shows the dependence of the lasing line intensity on the capillary length. From these data, using the Linford formula [59], the maximum gain gL = 7.2 was determined. Simultaneously, a weak amplification at a wavelength of 698 A corresponding to the 3p -3s transition (J = 0-+ J = I) in the same ion was observed [43].…”

Section: Lasing At 469 Amentioning

confidence: 99%