نتایج جستجو برای: photon contamination

تعداد نتایج: 123271  

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,...

Journal: :asia oceania journal of nuclear medicine and biology 0
kalevi kairemo department of molecular radiotherapy & nuclear medicine, docrates cancer center, helsinki, finland aki kangasmäki department of radiation physics, docrates cancer center, saukonpaadenranta, helsinki, finland

to the best of our knowledge, imaging of accidental exposure to radioactive fluorine-18 (f-18) due to liquid spill has not been described earlier in the scientific literature. the short half-life of f-18 (t½=110 min), current radiation safety requirements, and good manufacturing practice (gmp) regulations on radiopharmaceuticals have restrained the occurrence of these incidents. the possibility...

Journal: :Journal of synchrotron radiation 1998
D Shu H Ding J Barraza T M Kuzay D Haeffner M Ramanathan

At the Advanced Photon Source (APS), each insertion-device (ID) beamline front end has two X-ray beam position monitors (XBPMs) to monitor the X-ray beam position for both vertical and horizontal directions. Performance challenges for a conventional photoemission-type XBPM during operations are contamination of the signal from the neighbouring bending-magnet sources and the sensitivity of the X...

Journal: :Journal of Physics G: Nuclear and Particle Physics 2017

 To the best of our knowledge, imaging of accidental exposure to radioactive fluorine-18 (F-18) due to liquid spill has not been described earlier in the scientific literature. The short half-life of F-18 (t½=110 min), current radiation safety requirements, and Good Manufacturing Practice (GMP) regulations on radiopharmaceuticals have restrained the occurrence of these incidents. The possibilit...

ژورنال: سنجش و ایمنی پرتو 2018

Employing High-energy photons in medical linear accelerators can lead to neutron contamination. The relative biological effect of neutrons is 20 times higher than photons. Consequently, its damage to the biological tissue is much higher and unobtrusive. In this study, we calculated neutron equivalent dose in a medical linear accelerator by the FLUKA Monte Carlo code system. The results show tha...

2003
Wallace Murcray

The possible effect of contrails in modifying the weather is reconsidered in the light of information obtained from ground-level contrails in Alaska. It appears likely that inadvertent cloud seeding b y jet aircraft may be of the same order of magnitude as that attained in commercial cloud seeding operations. Further investigation is needed; but in the meantime, the possibility of contrail cont...

Journal: :Optics express 2017
Jacob G Koefoed Søren M M Friis Jesper B Christensen Karsten Rottwitt

We model the spectral quantum-mechanical purity of heralded single photons from a photon-pair source based on nondegenerate spontaneous four-wave mixing taking the impact of distributed dispersion fluctuations into account. The considered photon-pair-generation scheme utilizes pump-pulse walk-off to produce pure heralded photons and phase matching is achieved through the dispersion properties o...

2016
J. Ko I.-Y. Kim C. Kim D.-T. Kim J.-Y. Huang S. Shin

At third-generation light sources, the photon beam position stability is a critical issue for user experiments. In general, photon beam position monitors are developed to detect the real photon beam position, and the position is controlled by a feedback system in order to maintain the reference photon beam position. At Pohang Light Source II, a photon beam position stability of less than 1 µm r...

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