نتایج جستجو برای: electron beam pumping

تعداد نتایج: 413740  

Journal: :iranian journal of medical physics 0
nasrollah jabbari assistant professor, medical imaging dept., urmia university of medical sciences, urmia, iran. bijan hashemi associate professor, medical physics dept., tarbiat modarres university, tehran, iran.

introduction: in clinical electron beams, most of bremsstrahlung radiation is produced by various linac head structures. this bremsstrahlung radiation dose is influenced by the geometry and construction of every component of the linac treatment head structures. thus, it can be expected that the amount of the contaminated photon dose due to bremsstrahlung radiation varies among different linacs,...

2013
Y. H. Shi M. J. G. Lee M. Moskovits A. Hsu Robert W. Carpick

Raman spectroscopy, in which a laser beam serves the dual role of exciting the Raman spectrum and annealing the sample, shows promise as a means of investigating oxygen effects in the oxide superconductors. A technique is described, based on measurements of the ratios of the areas of corresponding peaks in the antiStokes and Stokes spectra, whereby the temperature of the illuminated region of t...

2014
Morgan N. Price Jayashree Ray Kelly M. Wetmore Jennifer V. Kuehl Stefan Bauer Adam M. Deutschbauer Adam P. Arkin

Sulfate-reducing bacteria play major roles in the global carbon and sulfur cycles, but it remains unclear how reducing sulfate yields energy. To determine the genetic basis of energy conservation, we measured the fitness of thousands of pooled mutants of Desulfovibrio alaskensis G20 during growth in 12 different combinations of electron donors and acceptors. We show that ion pumping by the ferr...

2002
M. L. Polianski M. G. Vavilov P. W. Brouwer

We study the current noise through an unbiased quantum electron pump and its mesoscopic fluctuations for arbitrary temperatures and beyond the bilinear response. In the bilinear regime, we find the full distributions of the noise power and the current-to-noise ratio for chaotic quantum dots with single-channel and many-channel ballistic point contacts. For a dot with many-channel point contacts...

E Akbari, H R Baghani H R Mirzaei K Tanha, M Mousavi, M Robatjazi, N Nafissi, S R Mahdavi,

Background: One of the main problems of dedicated IORT accelerators is to determine dosimetric characteristics of the electron beams. Monte Carlo simulation of IORT accelerator head and produced beam will be useful to improve the accuracy of beam dosimetry.Materials and Methods: Liac accelerator head was modeled using the BEAMnrcMonte Carlo simulation system. Phase-space files were generated at...

2014
Bhupesh Bhatia Vijayraj Shokeen Anuradha Bhasin Narendra Kumar E. P. Garate C. Shaughnessy J. Walsh R. Cook P. Heim Kazuyoshi Saito Ken Takayama Toshiyuki Ozaki Yukio Shibata Kimihiro Ishi Shuichi Ono F. Ciocci R. Bartolini A. Doria G. P. Gallerano

The Cerenkov free electron laser (CFEL) model under consideration consists of a pre-bunched relativistic electron beam and a dielectric loaded waveguide. The increase in the growth rate and gain with the change in phase by using a pre-bunched electron beam in a Cerenkov free electron laser (CFEL) has been studied. The growth rate and gain is calculated at experimentally known CFEL and FEL param...

2001
H. Z. Wu P. J. McCann O. Alkhouli X. M. Fang D. McAlister K. Namjou S. J. Chung P. H. O. Rappl

IV–VI semiconductor multiple quantum well ~MQW! structures ~PbSe/PbSrSe! were grown on Si~111! and BaF2~111! substrates by molecular beam epitaxy. Structural and optical properties of the MQW structures have been studied using reflection high-energy electron diffraction, high resolution x-ray diffraction ~HRXRD!, Fourier-transform infrared ~FTIR! transmission, and midinfrared photoluminescence ...

1999
V. Shiltsev

This article is devoted to electron beam distortions in the “electron compressor” setup for beam-beam compensation in the Tevatron collider. The distortions are due to interaction of the electron beam with impacting elliptical antiproton beam. We estimate of longitudinal magnetic field necessary to keep the distortions low.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علم و صنعت ایران - دانشکده فیزیک 1382

لیزر الکترون آزاد دستگاه تولید نورهمدوس با قابلیت بسیار است. عملا روی هر طول موج قابل تنظیم بوده و از بازده بسیار زیاد نیز برخوردار است که در آزمایشگاهها تا40 درصد و از نظر نظری تا 65 درصد قابل افزایش می باشد و بااین روند رشد همچنان ادامه دارد. نور این لیزرها در اثر برهم کنش سه عامل تولید می شود. باریکه الکترون، یک موج الکترومغناطیسی که در همان راستای حرکت الکترونها در کاواک لیزر حرکت می کند و ...

2001
Yu.Ya. Golub

The Budker-Chirikov instability (BCI) in a two-beam electron-ion system is researched. The BCI is due to the interaction of the slow cyclotron wave of the electron beam with the fast betatron wave of the ion beam. The electron-ion system consists of a high current relativistic electron beam propagating co-axially with a nonrelativistic ion beam in a drift tube. The external radii of the electro...

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