KARZMARK MEDICAL ELECTRON ACCELERATORS PDF
Library of Congress Cataloging-in-Publication Data Karzmark, C. J. Medical electron accelerators 1 C.J. Karzmark, Craig S. Nunan, and Eiji Tanabe. p. cm. : Medical Electron Accelerators: ** Signed gift inscription by co-author Craig Nunan to the previous owner on front endpaper **; Very. Medical Electron Accelerators by Karzmark, C. J.; Nunan, Craig S.; Tanabe, Eiji and a great selection of related books, art and collectibles available now at.
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Write a review Rate this item: Through the computational simulations, we have shown that such a system is capable of generating an electron beam suitable for therapeutic applications.
The spatial and energy characteristics of the electron beam were quantified at the accelerator target and compared to published data for conventional accelerators. Model of thermionic emission In conventional medical DC electron guns, a relatively low kilovoltage electrostatic field is applied to a thermionic cathode, resulting in space charge eledtron thermionic emission the space charge of the beam limits the emitted current.
Figure 9 A shows the target current as a function of SID within the fringe field of the 1 T superconducting magnet—for comparison purposes, the current of the conventional diode gun is also plotted.
The losses in the waveguide were calculated as a postprocessing step, which uses perturbation theory based on the magnetic field distribution at the walls.
Medical Electron Accelerators
Citations are based on reference standards. The energy and spatial distributions of the beam are shown in Fig. MRI guided radiotherapy is a rapidly growing field; however, current electron accdlerators are not designed to operate in electrln magnetic fringe fields of MRI scanners. Please verify that you are not a robot. It can be seen that whilst the median energy and current are barely changed by the addition of in-line fields, the spot size and interquartile range undergo large deviations compared to the zero field values.
The effects of both in-line and perpendicular magnetic fields on linear accelerator operation have previously been studied via computational simulations. Further investigation into back-bombardment, its impact on therapeutic beam quality, and mitigation strategies is warranted, but is beyond the scope of this work. Allow this favorite library to be seen by others Keep this favorite library private. A Comparison of the current loss versus distance from magnet isocenter for proposed system and a conventional DC electron gun.
On the other hand, if the dose per pulse remains consistent i. However, this ignores that both radiative and conductive heat dissipation are occurring.
The particles were scored at the accelerator exit for assessment. Published online Feb These numbers take into account all back accelerated electrons. A potential limitation of this work is that no power input port was incorporated into the simulation.
A novel electron accelerator for MRI-Linac radiotherapy
Please create a new list with a new name; move some items to a new or existing list; or delete some items. These values are all well within the capabilities of modern tungsten dispenser cathodes. Your list has reached the maximum number of items. In the proposed configuration, the megavoltage electric field at the cathode is constantly changing as the electric field oscillates back and forth. Theoretical current extracted from a thermionic cathode versus potential difference.
National Center for Biotechnology InformationU. The solver is based on the finite element method and utilizes a tetrahedral mesh with quadratic shape functions. There have also been triode based RF guns proposed—such a structure may be able to improve the system latency to that achievable with Accrlerators triode karzjark. We were not able to find any published literature on the typical extent of back-bombarded power in medical DC electron guns or any information on how much back-bombardment would be acceptable or unacceptable.
Second, any electron striking a DC cathode has to first navigate the anode drift tube and overcome the DC electric potential of the electron gun—meaning a cathode in a DC system has inherently greater protection from back-bombardment. You already recently rated this item. One of these is beam stability. Beam assessment at the target In order to assess the performance acceleratos the RF gun based accelerator, a beam monitor was placed at the exit of the simulation; particle information was scored as it crossed this monitor and exported to matlab acccelerators further analysis.
However, both issues have been solved in many epectron RF guns previously and as such are not anticipated to present major challenges. As such, there are only two changes to the initial geometry published by St. B Energy histogram at the target. Please choose whether or zccelerators you want other users to be able to see on your profile that this library is a favorite of yours. Home About Help Search. In order to compare this to a conventional system, the RF source from Sec.
The waveguide structure was discretized into 4.
You may have already requested this item. The E-mail Address es you entered is are not in a valid format. It can be seen that the bunch power rises steadily before plateauing; this behavior occurs because the mean energy of the back-bombarded electrons kafzmark as the forward directed beam propagates further down the accelerator.
A10—21 Note that the SID is approximately mm smaller than the cathode to isocenter distance. Find a copy in the library Finding libraries that hold this item