scholarly journals Efficient hard X-ray source using femtosecond plasma at solid targets with a modified surface

2004 ◽  
Vol 22 (3) ◽  
pp. 301-306 ◽  
Author(s):  
S.A. GAVRILOV ◽  
D.M. GOLISHNIKOV ◽  
V.M. GORDIENKO ◽  
A.B. SAVEL'EV ◽  
R.V. VOLKOV
Keyword(s):  
Experimental Data ◽  
Surface Layer ◽  
Laser Pulses ◽  
Hot Electron ◽  
High Contrast ◽  
X Ray ◽  
Corrugated Surface ◽  
Fs Laser ◽  
Modified Surface ◽  
Modified Surface Layer

Recent results on constructing of an efficient hard X-ray source using solid targets irradiated by high-contrast 200-fs laser pulses with an intensity above 1016W/cm2are presented. We used different solid targets with a laser- and electrochemically modified surface layer: craters, pyramidal cavities, porous silicon, gratings. Experimental data obtained confirms that using solid targets with a corrugated surface one can achieve a prominent increase both in the efficiency of hard X-ray generation (in the quanta range 2–30 keV) and in the hot electron temperature of plasma.

Efficiency enhancement of Cu 2 ZnSn(S,Se) 4 solar cells by S-modified surface layer

2017 ◽  
Vol 162 ◽  
pp. 21-29 ◽  
Author(s):  
Chung-Hao Cai ◽  
Shih-Yuan Wei ◽  
Wei-Chih Huang ◽  
Chia-Hao Hsu ◽  
Wei-Hao Ho ◽  
...  
Keyword(s):  
Surface Layer ◽  
Solar Cells ◽  
Efficiency Enhancement ◽  
Modified Surface ◽  
Modified Surface Layer

Demonstration of thin film compression for short-pulse X-ray generation

2019 ◽  
Vol 34 (34) ◽  
pp. 1943015
Author(s):  
D. M. Farinella ◽  
M. Stanfield ◽  
N. Beier ◽  
T. Nguyen ◽  
S. Hakimi ◽  
...  
Keyword(s):  
Thin Film ◽  
Imaging System ◽  
Short Pulse ◽  
Laser Pulses ◽  
Single Cycle ◽  
X Ray ◽  
Ultrafast Laser Pulses ◽  
Solid Density ◽  
Fs Laser ◽  
Gaussian Mode

Thin film compression to the single-cycle regime combined with relativistic compression offers a method to transform conventional ultrafast laser pulses into attosecond X-ray laser pulses. These attosecond X-ray laser pulses are required to drive wakefields in solid density materials which can provide acceleration gradients of up to TeV/cm. Here we demonstrate a nearly 99% energy efficient compression of a 6.63 mJ, 39 fs laser pulse with a Gaussian mode to 20 fs in a single stage. Further, it is shown that as a result of Kerr-lensing, the focal spot of the system is slightly shifted on-axis and can be recovered by translating the imaging system to the new focal plane. This implies that with the help of wave-front shaping optics the focusability of laser pulses compressed in this way can be partially preserved.

Transient Electrochemical Measurements During Copper Chemical Mechanical Polishing

2003 ◽  
Vol 767 ◽  
Author(s):  
Seung-Mahn Lee ◽  
Wonseop Choi ◽  
Valentin Craciun ◽  
Rajiv K. Singh
Keyword(s):  
Surface Layer ◽  
Reaction Kinetics ◽  
Chemical Mechanical Polishing ◽  
Copper Surface ◽  
Mechanical Polishing ◽  
Electrochemical Measurements ◽  
Chemically Modified ◽  
Modified Surface ◽  
Selection Of ◽  
Modified Surface Layer

AbstractChronoamperometry was used to investigate the reaction/passivation kinetics and thickness of the chemically modified surface layer on the copper during chemical mechanical polishing (CMP). The result showed that the reaction/passivation kinetics and the thickness of the chemically modified surface layer are strongly dependent on the chemistry of CMP slurry in the chemical aspect of CMP and play critical keys in the selection of the chemistry and its concentration. BTA and H2O2 enhanced the passivation kinetics, resulting in thinner layer on the copper surface. In addition, the reaction kinetics increased as pH decreased.

Corrosion Characteristics of Surface-Modified DET Magnesium Powders

2004 ◽  
Vol 449-452 ◽  
pp. 369-372
Author(s):  
W.S. Chung ◽  
W.Y. Yoon ◽  
Kwang Jin Kim
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Current Density ◽  
Nacl Solution ◽  
Composition Distribution ◽  
Passive Behavior ◽  
Modified Surfaces ◽  
Modified Surface ◽  
Surface Modified ◽  
Modified Surface Layer

Magnesium powders having inactive surface layer have been processed easily and intentionally by DET under fluoride, chromate, and bromide salt. The modified surfaces play an important role in preventing contact with active environments to improve corrosion resistance of Magnesium powders; the image of the surface modified powders was observed using SEM. The composition distribution and characteristics was determined and analyzed by using XRD, XPS, and EIS. Compared with bare Magnesium, the Magnesium having chromate modified surface layer showed a more passive behavior such as smaller current density and nobler potential in 4wt% NaCl solution.

X-ray polarization-dependent measurements of solid-density plasmas generated by fs laser pulses

2007 ◽  
Vol 3 (1-2) ◽  
pp. 297-301 ◽  
Author(s):  
F. Zamponi ◽  
A. Lübcke ◽  
T. Kämpfer ◽  
I. Uschmann ◽  
E. Förster ◽  
...  
Keyword(s):  
Laser Pulses ◽  
X Ray ◽  
Solid Density ◽  
Fs Laser

scholarly journals Evaluation of Properties of the Laser Modified Surface Layer

1999 ◽  
Vol 96 (2) ◽  
pp. 263-273
Author(s):  
A. Bień ◽  
W. Szachnowski
Keyword(s):  
Surface Layer ◽  
Modified Surface ◽  
Modified Surface Layer

scholarly journals Исследование изменения микротвердости поверхности циркония после лазерной модифицирующей обработки

2019 ◽  
Vol 45 (6) ◽  
pp. 20 ◽  
Author(s):  
В.И. Проскуряков ◽  
И.В. Родионов ◽  
В.А. Кошуро
Keyword(s):  
Surface Layer ◽  
Laser Action ◽  
Pulsed Laser ◽  
Hardened Layer ◽  
Bulk Metal ◽  
Transition Zones ◽  
Zirconium Oxides ◽  
E110 Alloy ◽  
Modified Surface ◽  
Modified Surface Layer

AbstractThe results of an investigation of the process of laser-induced hardening of zirconium (E110 alloy) are reported. It has been established that the laser treatment in air results in the formation of a uniformly distributed microrelief characterized by the presence of microparticles with various configurations. Overlap of the laser beam trajectories leads to the formation of a layered structure. The composition of laser-modified surface depends on the regime of processing and mostly comprises a mixture of zirconium oxides and nitrides. In addition, the formation of diffuse transition zones between the bulk metal and modified surface layer is established. The dependence of the thickness of the hardened layer on the regime of pulsed laser action is determined.

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