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Title: Efficient K-shell x-ray sources produced with titanium foils

Abstract

The conversion efficiency of titanium K-shell x rays is experimentally investigated in the Shenguang II laser facility. For comparison, Ti foils with the thickness of 3.5 and 5.8 {mu}m are irradiated under the same laser condition. The conversion efficiency with the thinner foils reaches about 3.5% and is about two times of that obtained with the thicker foils. The experiments show that the enhancement of the conversion efficiency should be due to the larger size of hot underdense plasmas generated with the thinner foil.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ;  [1];  [2];  [3];  [4];  [3];  [3]
  1. CAS Key Laboratory of Basic Plasma Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)
  2. (China) and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China)
  3. (China)
  4. (China) and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)
Publication Date:
OSTI Identifier:
20974888
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 14; Journal Issue: 3; Other Information: DOI: 10.1063/1.2446286; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPARATIVE EVALUATIONS; EFFICIENCY; FOILS; IRRADIATION; K SHELL; LASERS; LIGHT TRANSMISSION; PLASMA; PLASMA PRODUCTION; THICKNESS; TITANIUM; X RADIATION; X-RAY SOURCES

Citation Formats

Hu Guangyue, Liu Shenye, Zheng Jian, Wu Changshu, Li Jinghong, Wu Shunchao, Zhang Jiyan, Yang Jiamin, Yang Guohong, Yi Rongqing, Du Huabing, Huang Yixiang, Hu Xin, Ding Yongkun, Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900, CAS Key Laboratory of Basic Plasma Physics, University of Science and Technology of China, Hefei, Anhui 230026, Institute of Applied Physics and Computational Mathematics, China Academy of Engineering Physics, Beijing, 100088, and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900. Efficient K-shell x-ray sources produced with titanium foils. United States: N. p., 2007. Web. doi:10.1063/1.2446286.
Hu Guangyue, Liu Shenye, Zheng Jian, Wu Changshu, Li Jinghong, Wu Shunchao, Zhang Jiyan, Yang Jiamin, Yang Guohong, Yi Rongqing, Du Huabing, Huang Yixiang, Hu Xin, Ding Yongkun, Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900, CAS Key Laboratory of Basic Plasma Physics, University of Science and Technology of China, Hefei, Anhui 230026, Institute of Applied Physics and Computational Mathematics, China Academy of Engineering Physics, Beijing, 100088, & Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900. Efficient K-shell x-ray sources produced with titanium foils. United States. doi:10.1063/1.2446286.
Hu Guangyue, Liu Shenye, Zheng Jian, Wu Changshu, Li Jinghong, Wu Shunchao, Zhang Jiyan, Yang Jiamin, Yang Guohong, Yi Rongqing, Du Huabing, Huang Yixiang, Hu Xin, Ding Yongkun, Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900, CAS Key Laboratory of Basic Plasma Physics, University of Science and Technology of China, Hefei, Anhui 230026, Institute of Applied Physics and Computational Mathematics, China Academy of Engineering Physics, Beijing, 100088, and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900. Thu . "Efficient K-shell x-ray sources produced with titanium foils". United States. doi:10.1063/1.2446286.
@article{osti_20974888,
title = {Efficient K-shell x-ray sources produced with titanium foils},
author = {Hu Guangyue and Liu Shenye and Zheng Jian and Wu Changshu and Li Jinghong and Wu Shunchao and Zhang Jiyan and Yang Jiamin and Yang Guohong and Yi Rongqing and Du Huabing and Huang Yixiang and Hu Xin and Ding Yongkun and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 and CAS Key Laboratory of Basic Plasma Physics, University of Science and Technology of China, Hefei, Anhui 230026 and Institute of Applied Physics and Computational Mathematics, China Academy of Engineering Physics, Beijing, 100088 and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900},
abstractNote = {The conversion efficiency of titanium K-shell x rays is experimentally investigated in the Shenguang II laser facility. For comparison, Ti foils with the thickness of 3.5 and 5.8 {mu}m are irradiated under the same laser condition. The conversion efficiency with the thinner foils reaches about 3.5% and is about two times of that obtained with the thicker foils. The experiments show that the enhancement of the conversion efficiency should be due to the larger size of hot underdense plasmas generated with the thinner foil.},
doi = {10.1063/1.2446286},
journal = {Physics of Plasmas},
number = 3,
volume = 14,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
  • A set of materials--titanium, copper, and germanium--has been experimented with at the OMEGA laser facility [Boehly, Opt. Commun. 133, 495 (1997)] by irradiating thin foils with a prepulse prior to a main pulse with variable delay, in order to design efficient x-ray laser-sources for backlighting, material testing, and code validation. This concept led to increasing factors from 2 to 4 comparing to cases without prepulse, in the experimental conditions. As a result, high multi-keV x-ray conversion rates have been obtained: 9% for titanium around 4 keV, 1% for copper around 8 keV, and 2.5 to 3% for germanium around 10more » keV, which places these pre-exploded metallic targets close to the gas with respect to their performance, with wider energy range. A good agreement with hydroradiative code FCI2[Schurtz, Phys. Plasmas 7, 4238 (2000)] calculations is found for titanium and copper on all diagnostics, with nonlocal-thermal-equilibrium atomic physics and, either nonlocal thermal conduction taking self-generated B-fields into account, or limited thermal conduction with intensity-dependent factor f. The results for germanium indicate that dielectronic processes could play a more significant role when higher irradiation intensity on higher Z material.« less
  • Experimental results obtained within the last fifteen years on multi-keV X-ray sources irradiated with nanosecond scale pulse duration 3ω laser light at TW power levels by CEA and collaborators are discussed in this review paper. Experiments were carried out on OMEGA and GEKKO XII laser facilities where emitting materials in the 5–10 keV multi-keV energy range are intermediate Z value metals from titanium to germanium. Results focused on conversion efficiency improvement by a factor of 2 when an underdense plasma is created using a laser pre-pulse on a metallic foil, which is then heated by a second laser pulse delayed inmore » time. Metal coated inner surface walls of plastic cylindrical tube ablated by laser beam impacts showed that plasma confinement doubles X-ray emission duration as it gives adequate plasma conditions (electron temperature and density) over a long period of time. Low-density aerogels (doped with metal atoms uniformly distributed throughout their volume or metal oxides) contained in a plastic cylinder have been developed and their results are comparable to gas targets. A hybrid target concept consisting of a thin metal foil placed at the end of a cylinder filled with low density aerogel has emerged as it could collect benefits from pre-exploded thin foils, efficient laser absorption in aerogel, and confinement by cylinder walls. All target geometry performances are relatively close together at a given photon energy and mainly depend on laser irradiation condition optimizations. Results are compared with gas target performances from recent NIF experiments allowing high electron temperatures over large dimension low density plasmas, which are the principal parameters for efficient multi-keV X-ray production.« less
  • Photon sources produced by laser beams with moderate laser intensities, up to 10{sup 14 }W/cm{sup 2}, are being developed for many industrial applications. The performance requirements for high volume manufacture devices necessitate extensive experimental research supported by theoretical plasma analysis and modeling predictions. We simulated laser produced plasma sources currently being developed for several applications such as extreme ultraviolet lithography using 13.5% ± 1% nm bandwidth, possibly beyond extreme ultraviolet lithography using 6.× nm wavelengths, and water-window microscopy utilizing 2.48 nm (La-α) and 2.88 nm (He-α) emission. We comprehensively modeled plasma evolution from solid/liquid tin, gadolinium, and nitrogen targets as three promising materials for themore » above described sources, respectively. Results of our analysis for plasma characteristics during the entire course of plasma evolution showed the dependence of source conversion efficiency (CE), i.e., laser energy to photons at the desired wavelength, on plasma electron density gradient. Our results showed that utilizing laser intensities which produce hotter plasma than the optimum emission temperatures allows increasing CE for all considered sources that, however, restricted by the reabsorption processes around the main emission region and this restriction is especially actual for the 6.× nm sources.« less
  • The advent of the 20-MA Z accelerator [R.B. Spielman, C. Deeney, G.A. Chandler, et al., Phys. Plasmas 5, 2105, (1997)] has enabled implosions of large diameter, high-wire-number arrays of titanium to begin testing Z-pinch K-shell scaling theories. The 2-cm long titanium arrays, which were mounted on a 40-mm diameter, produced between 75{+-}15 to 125{+-}20 kJ of K-shell x-rays. Mass scans indicate that, as predicted, higher velocity implosions in the series produced higher x-ray yields. Spectroscopic analyses indicate that these high velocity implosions achieved peak electron temperatures from 2.7{+-}0.1 to 3.2{+-}0.2 keV and obtained a K-shell emission mass participation of upmore » to 12%.« less