نتایج جستجو برای: ray laser

تعداد نتایج: 478312  

Journal: :Optics letters 2001
J Larsson

A novel method developed to increase the temporal resolution of x-ray streak cameras is described. The method is analogous to the time-correlated single-photon-counting technique, which is commonly used in atomic physics. By use of short-pulse x-ray radiation from a laser-produced plasma, generated by an ultrafast laser, it is shown that a standard x-ray streak camera with a nominal temporal re...

Journal: :Optics letters 2009
Ping-Hsun Lin Ming-Chang Chou Ming-Jhe Jiang Po-Chang Tseng Hsu-Hsin Chu Jiunn-Yuan Lin Jyhpyng Wang Szu-Yuan Chen

A strongly saturated waveguide-based optical-field-ionization soft-x-ray laser seeded by high harmonic generation was demonstrated for Ni-like Kr lasing at 32.8 nm. Compared with the same laser seeded only with spontaneous emission, seeding with high harmonics yields much smaller divergence, enhanced spatial coherence, and controlled polarization. The integration of high harmonic seeding, optic...

Journal: :iranian journal of medical sciences 0
b. forogh a. ghasemzadeh a. salimzadeh

the objective of this study was to validate the use of bone mineral measurements of the calcaneus bone by dual x-ray and laser (dxl) in a cross-sectional study carried out in an osteoporosis clinic. measurements of bone mineral density (bmd) at proximal femur and spine were obtained by dual-energy photon x-ray absorptiometry (dexa). osteoporosis was defined by a dexa t-score <-2.5 at the femora...

پایان نامه :دانشگاه آزاد اسلامی واحد علوم پزشکی تهران - دانشکده پزشکی 1390

هدف: این مطالعه به منظور بررسی و مقایسه اثر q-switched nd yag laser و erbium laser در درمان ضایعات پیگمانته انجام شده است. روش مطالعه: 116 فرد مبتلا به ضایعات پیگمانته از نوع فرکل و خال وارد مطالعه شدند که 58 مورد با استفاده از q-switched nd yag laser و 58 مورد با لیزر erbium درمان شدند و در نهایت میزان اثربخشی (از بین رفتن کامل ضایعات) در دو گروه تعیین و مقایسه گردید. یافته ها: در این مطالعه...

2002
J. Yang M. Yorozu F. Sakai T. Yanagida Y. Okada S. Ito K. Takasago A. Endo

A femtosecond X-ray source was developed by Thomson scattering through interaction between a lowemittance picosecond electron beam and a terawatt femtosecond laser light at 90 configuration. The observed X-ray intensity with peak energy of 2.3 keV and pulse duration of 270 fs rms was typically 1.4x10 photons/pulse. The pulse-to-pulse fluctuation of the X-ray intensity was measured to be 25%. Th...

1974
F. T. ARECCHI

Photoelectric pumping of inner shells of intermediate Z materials is shown to be efficient for inverting the population ot" radiative transitions around 1 keV. Non-radiative processes are shown to be essential for achieving a stationdry inversion. Reported intense X-ray bursts from plasmas generated by laser radiation suggest the use of a Nd laser as exciting source. Threshold evaluations show ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2015
Elena Eggl Simone Schleede Martin Bech Klaus Achterhold Roderick Loewen Ronald D Ruth Franz Pfeiffer

Between X-ray tubes and large-scale synchrotron sources, a large gap in performance exists with respect to the monochromaticity and brilliance of the X-ray beam. However, due to their size and cost, large-scale synchrotrons are not available for more routine applications in small and medium-sized academic or industrial laboratories. This gap could be closed by laser-driven compact synchrotron l...

2015
Michael P. Minitti Joseph S. Robinson Ryan N. Coffee Steve Edstrom Sasha Gilevich James M. Glownia Eduardo Granados Philippe Hering Matthias C. Hoffmann Alan Miahnahri Despina Milathianaki Wayne Polzin Daniel Ratner Franz Tavella Sharon Vetter Marc Welch William E. White Alan R. Fry

Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump-probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manu...

2012
R. J. Clarke D. Neely S. Blake D. C. Carroll J. S. Green R. Heathcote M. Notley

High Power Lasers produce an intense burst of Bremmstrahlung radiation which has potential applications in broadband x-ray radiography. Since the radiation produced is through the interaction of accelerated electrons with the remaining laser target, these bursts are extremely short – in the region of a few ps. As a result, the laser-produced x-rays are capable of imaging complex dynamic objects...

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