Soft-x-ray amplification by lithiumlike ions in recombining hot plasmas

Jaeglé, P.; Jamelot, G.; Carillon, A.; Klisnick, A.; Sureau, A.; Guennou, H.

doi:10.1364/josab.4.000563

Cited by 109 publications

(25 citation statements)

References 19 publications

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“…41,160-165 Gain has been reported in H-like Na ions, 163 in the 4 f -3d and 5 f -3d lines of Li-like ions, [164][165][166] and in Be-like and Na-like ions. 170 An important advantage of the recombination scheme with respect to the collisional excitation scheme involving ⌬nϭ0 transitions is its more rapid scaling to shorter wavelengths with nuclear charge Z.…”

Section: B Collisional Recombinationmentioning

confidence: 98%

“…The required cooling rate is determined by the recombination rate. The plasma can be rapidly cooled by an adiabatic expansion, 30,31,37,127,[159][160][161][162][163][164][165][166] by electron heat conduction to a nearby wall or colder neighboring plasma, 167 or by radiation from high-Z ions introduced as impurities into the plasma. 168,169 All three cooling mechanisms, or combinations of them, have been utilized experimentally to generate gain at soft x-ray wavelengths by collisional electron-ion recombination.…”

Section: B Collisional Recombinationmentioning

confidence: 99%

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Table-top Soft X-Ray Lasers

Rocca

2016

Conference on Lasers and Electro-Optics

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This article reviews the progress in the development of practical table-top sources of soft x-ray laser radiation. The field is rapidly approaching the stage at which soft x-ray lasers sufficiently compact to fit onto a normal optical table will be routinely utilized in science and technology. This is the result of recent advances in the amplification of soft x-ray radiation in both compact laser-pumped and discharge-pumped devices. The use of excitation mechanisms that take full advantage of new ultrafast high power optical laser drivers and multiple pulse excitation schemes has resulted in the demonstration of saturated soft x-ray amplification at wavelengths as short as 14 nm using several Joule of laser-pump energy. Moreover, several schemes have demonstrated significant gain with only a fraction of a Joule of laser-pump energy. In addition, the demonstration of saturated table-top soft x-ray lasers pumped by very compact capillary discharges has shattered the notion that discharge-created plasmas are insufficiently uniform to allow for soft x-ray amplification, opening a route for the development of efficient, high average power soft x-ray lasers. Recently, a table-top capillary discharge laser operating at 46.9 nm has produced millijoule-level laser pulses at a repetition rate of several Hz, with a corresponding spatially coherent average power per unit bandwidth comparable to that of a beam line at a third generation synchrotron facility. This review summarizes fundamental and technical aspects of table-top soft x-ray lasers based on the generation of population inversions in plasmas, and discusses the present status of development of specific laser systems.

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Section: B Collisional Recombinationmentioning

confidence: 98%

Section: B Collisional Recombinationmentioning

confidence: 99%

Table-top Soft X-Ray Lasers

Rocca

2016

Conference on Lasers and Electro-Optics

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“…7.79Â10 -3 7.69Â10 -3 Reduced population of Ni(XVIII) levels at temperature 1/4 ionization potential 1.00Â10 10 1.44Â10 -14 1.95Â10 -13 1.86Â10 -13 1.00Â10 11 1.44Â10 -13 1.95Â10 -12 1.86Â10 -12 1.00Â10 12 1.44Â10 -12 1.95Â10 -11 1.86Â10 -11 1.00Â10 13 1.44Â10 -11 1.95Â10 -10 1.86Â10 -10 1.00Â10 14 1.45Â10 -10 1.95Â10 -9 1.86Â10 -9 1.00Â10 15 1.53Â10 -9 1.94Â10 -8 1.85Â10 -8 1.00Â10 16 2.31Â10 -8 1.85Â10 -7 1.81Â10 -7 3.96Â10 -3 3.91Â10 -3 1.00Â10 22 7.81Â10 -3 7.05Â10 -3 6.95Â10 -3 1.00Â10 23 8.49Â10 -3 7.67Â10 -3 7.56Â10 -3 1.00Â10 24 8.57Â10 -3 7.74Â10 -3 7.63Â10 -3 1.00Â10 25 8.58Â10 -3 7.75Â10 -3 7.64Â10 -3 Reduced population of Cu(XIX) levels at temperature 1/4 ionization potential 1.00Â10 10 1.02Â10 -14 1.48Â10 -13 1.40Â10 -13 1.00Â10 11 1.02Â10 -13 1.48Â10 -12 1.40Â10 -12 1.00Â10 12 1.02Â10 -12 1.48Â10 -11 1.40Â10 -11 1.00Â10 13 1.02Â10 -11 1.48Â10 -10 1.40Â10 -10 1.00Â10 14 1.03Â10 -10 1.48Â10 -9 1.40Â10 -9 1.00Â10 15 1.08Â10 -9 1.47Â10 -8 1.40Â10 -8 1.00Â10 16 1.56Â10 -8 1.42Â10 -7 1.37Â10 -7 1.00Â10 17 4.86Â10 -7 1.14Â10 -6 1.12Â10 -6 1.00Â10 18 9.56Â10 - 6 6.53Â10 -6 6.42Â10 -6 1.00Â10 19 …”

Section: Calculation Of Level Populationsmentioning

confidence: 99%

“…Hagelstein et al [4] observed stimulated emission in the soft X-ray spectral region in the Ni-sequence by the collisional excitation scheme of elements of low atomic numbers. An extensive series of experiments for developing a soft X-ray laser using the Li-sequence was performed by Jeagle et al [5,6] using a high-power laser for pumping Al-targets. Silfvast and Wood [7] obtained a soft X-ray oscillator and amplifier from the Na-sequence by photoionization pumping with laser-produced plasmas.…”

Section: Introductionmentioning

confidence: 99%

Rate coefficients for electron impact excitation, de-excitation and laser gain calculations of the excited ions Co(XVII) up to Br(XXV)

2010

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Rate coefficients for electron impact excitation, de-excitation, and total depopulation of the excited ions Co(X-VII) up to Br(XXV) of the sodium isoelectronic sequence are calculated according to the analytical formulas of Vriens and Smeets. A simple modification has been made by substituting effective quantum numbers in Vriens' formulas to be applicable for the ions under consideration. The energy levels and transition probabilities have been calculated using Hibbert's configuration interaction computer package (CIV3). Level population densities are then calculated by solving the coupled rate equations involving the 19 levels 1s 2 2s 2 2p 6 nl, where n = 3,4,5 and l = 0,1,2,3. Positive gain coefficients are displayed for the transitions 4p( 2 P1/2) ? 4s( 2 S1/2) and 4p( 2 P3/2) ? 4s( 2 S1/2) at three selected electron temperatures, namel, 1/4, 1/2, and 3/4 the ionization potential of each ion, respectively.Résumé : Les coefficients de rendement d'excitation par impact électronique, de désexcitaton et de dépopulation totale des ions excités, allant du Co(XVII) au Br(XXV) de la séquence isoélectronique du sodium ont été calculés à l'aide des formules analytiques de Vriens et Smeets. Une simple modification a été apportée pour substituer les nombres quantiques effectifs dans la formule de Vriens pour la rendre applicable aux ions étudiés. Nous avons calculé les niveaux d'énergie et les probabilités de transition à l'aide du programme CIV3 qui utilise les interactions entre configuration d'Hilbert. Les densités de population sont alors calculées en solutionnant les équations couplées pour les vitesses de réaction impliquant les 19 niveaux 1s 2 2s 2 2p 6 nl, où n = 3, 4, 5 et l = 0, 1, 2, 3. Nous présentons les coefficients de gain positif pour les transitions 4p( 2 P 1/2 ) ? 4s( 2 S 1/2 ) and 4p( 2 P 3/2 ) ? 4s( 2 S 1/2 ), pour trois températures sélectionnées, nommément 1/4, 1/2 et 3/4 du potentiel d'ionisation de chaque ion respectivement.[Traduit par la Rédaction]

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“…One of the features of the target system was the capability of rotating the target so that for every shot a fresh target surface is exposed by the laser. A similar condition was created in the experiments performed by Jaegl6 et al 9 by translation of a plane aluminum target. The gain was measured by changing the target length and hence the plasma length, as shown in Fig.…”

mentioning

confidence: 99%

Gain measurements at 1822 nm in C vi generated by a Nd:glass laser

et al. 1989

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We present recent gain measurements in C VI at 18.22 nm for a soft-x-ray amplifier produced by a line-focused glass laser (1.053 sm) on a solid carbon target. The maximum gain measured was 8 + 2 cm-' in the recombining plasma column, with additional radiation cooling by iron impurities.Recent research in soft-x-ray laser development is progressing in the direction of obtaining shorter wavelengths. Significant advances are also being made in the XUV region. Much attention is being devoted to the first applications of these lasers. The possibility of using soft-x-ray lasers for the microscopy of living cells has stimulated research in the development of xray lasers operating in the wavelength region of 2.33-4.37 nm, the so-called water window. 1 ' 2 Impressive advances in longer-wavelength XUV lasers, such as the one recently demonstrated at 108.9 nm, 3 ' 4 have significant potential applications in chemistry. An important point, however, that is rarely discussed is the laser energy required for these applications. For example, in order to record a high-resolution image of a biological cell on a photoresist, substantial laser beam energy is required. This is a significant concern in our current soft-x-ray microscopy experiments, 5 even for the maximum output energy of our current 18.22-nm laser. 6 We have, therefore, applied a significant effort to increase the energy of the 18.22-nm soft-x-ray laser. One approach has been to develop additional amplifiers. This technique can also be applied to the shorterwavelength region, where our current goals include the generation of lasing action near 10.0 nm, using ions in the Li-like sequence, 7 and down to 1.0 nm, using a powerful picosecond laser for selective excitation. In this Letter we present the first step in developing such amplifiers by the generation of gain in C VI at 18.22 nm using a Nd:glass laser beam brought to a line focus on a solid carbon target in a strong magnetic field (field lines parallel to the line focus). The role of the magnetic field is considered to be less important here than in our research in generating gain at 18.22 nm using a CO 2 laser that is point focused along the magnetic-field axis because of a much higher initial electron density for the 1-gum Nd:glass laser than for the 10-gum CO 2 laser. However, in the future we plan to combine this amplifier with our C0 2 -laser-pumped, magnetically confined soft-x-ray laser; thus it is necessary that the Nd:glass-laser-pumped amplifier also work in a magnetic field and have a similar transverse dimension.In the experiments the maximum pumping laser energy used was 40 J, which was limited by the area of the beam input optics, and the pulse duration was 3 nsec. The 5.1-cm-diameter laser beam was line focused onto the cylindrical target by the combination of a 67-cm focal-length spherical lens and a 450-cm focallength cylindrical lens (Fig. 1). The dimensions of the line focus were -100 gim X 5 mm. The length of the line focus was limited by the size of the magnet port.

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Soft-x-ray amplification by lithiumlike ions in recombining hot plasmas

Cited by 109 publications

References 19 publications

Table-top Soft X-Ray Lasers

Table-top Soft X-Ray Lasers

Rate coefficients for electron impact excitation, de-excitation and laser gain calculations of the excited ions Co(XVII) up to Br(XXV)

Gain measurements at 1822 nm in C vi generated by a Nd:glass laser

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