Dose Distribution Due to Low-Energy Electrons and Delta Rays Produced along the Path of a Heavy Charged Particle in Water

1978 ◽  
Vol 76 (1) ◽  
pp. 1 ◽  
Author(s):  
S. K. Gupta ◽  
M. A. Prasad
Keyword(s):  
Charged Particle ◽  
Dose Distribution ◽  
Low Energy ◽  
Heavy Charged Particle ◽  
Low Energy Electrons

Effect of tissue inhomogeneity on dose distribution of point sources of low-energy electrons

1990 ◽  
Vol 17 (5) ◽  
pp. 786-793 ◽  
Author(s):  
Cheuk S. Kwok ◽  
Philip J. Bialobzyski ◽  
Siu K. Yu ◽  
William V. Prestwich
Keyword(s):  
Dose Distribution ◽  
Point Sources ◽  
Low Energy ◽  
Low Energy Electrons ◽  
Tissue Inhomogeneity

Magnitude of Residual Internal Anatomy Motion on Heavy Charged Particle Dose Distribution in Respiratory Gated Lung Therapy

2008 ◽  
Vol 71 (2) ◽  
pp. 587-594 ◽  
Author(s):  
Shinichiro Mori ◽  
Hiroshi Asakura ◽  
Susumu Kandatsu ◽  
Motoki Kumagai ◽  
Masayuki Baba ◽  
...  
Keyword(s):  
Charged Particle ◽  
Dose Distribution ◽  
Heavy Charged Particle ◽  
Internal Anatomy ◽  
Particle Dose

Transfer optics for high spatial resolution electron spectroscopy

1988 ◽  
Vol 46 ◽  
pp. 666-667
Author(s):  
G. G. Hembree ◽  
Luo Chuan Hong ◽  
P.A. Bennett ◽  
J.A. Venables
Keyword(s):  
Magnetic Field ◽  
Scanning Transmission Electron Microscope ◽  
Low Energy ◽  
Objective Lens ◽  
State University ◽  
Arizona State University ◽  
Initial Field ◽  
Resolution Electron ◽  
Scanning Transmission ◽  
Low Energy Electrons

A new field emission scanning transmission electron microscope has been constructed for the NSF HREM facility at Arizona State University. The microscope is to be used for studies of surfaces, and incorporates several surface-related features, including provision for analysis of secondary and Auger electrons; these electrons are collected through the objective lens from either side of the sample, using the parallelizing action of the magnetic field. This collimates all the low energy electrons, which spiral in the high magnetic field. Given an initial field Bi∼1T, and a final (parallelizing) field Bf∼0.01T, all electrons emerge into a cone of semi-angle θf≤6°. The main practical problem in the way of using this well collimated beam of low energy (0-2keV) electrons is that it is travelling along the path of the (100keV) probing electron beam. To collect and analyze them, they must be deflected off the beam path with minimal effect on the probe position.

Preincubation with Sn-complexes causes intensive intracellular retention of 99mTc in thyroid cells in vitro

2012 ◽  
Vol 51 (05) ◽  
pp. 179-185 ◽  
Author(s):  
M. Wendisch ◽  
D. Aurich ◽  
R. Runge ◽  
R. Freudenberg ◽  
J. Kotzerke ◽  
...  
Keyword(s):  
Cell Model ◽  
Low Energy ◽  
Thyroid Cells ◽  
Low Energy Electrons ◽  
A Cell ◽  
Vitro Model ◽  
Uptake Studies ◽  
Radiobiological Effects ◽  
Radioactivity Retention

SummaryTechnetium radiopharmaceuticals are well established in nuclear medicine. Besides its well-known gamma radiation, 99mTc emits an average of five Auger and internal conversion electrons per decay. The biological toxicity of these low-energy, high-LET (linear energy transfer) emissions is a controversial subject. One aim of this study was to estimate in a cell model how much 99mTc can be present in exposed cells and which radiobiological effects could be estimated in 99mTc-overloaded cells. Methods: Sodium iodine symporter (NIS)- positive thyroid cells were used. 99mTc-uptake studies were performed after preincubation with a non-radioactive (cold) stannous pyro - phosphate kit solution or as a standard 99mTc pyrophosphate kit preparation or with pure pertechnetate solution. Survival curves were analyzed from colony-forming assays. Results: Preincubation with stannous complexes causes irreversible intracellular radioactivity retention of 99mTc and is followed by further pertechnetate influx to an unexpectedly high 99mTc level. The uptake of 99mTc pertechnetate in NIS-positive cells can be modified using stannous pyrophosphate from 3–5% to >80%. The maximum possible cellular uptake of 99mTc was 90 Bq/cell. Compared with nearly pure extracellular irradiation from routine 99mTc complexes, cell survival was reduced by 3–4 orders of magnitude after preincubation with stannous pyrophosphate. Conclusions: Intra cellular 99mTc retention is related to reduced survival, which is most likely mediated by the emission of low-energy electrons. Our findings show that the described experiments constitute a simple and useful in vitro model for radiobiological investigations in a cell model.

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