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argon_dbd_1d example

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In argon_dbd_1d example, the forward rate constants for Ar*+Ar* ==> e+ Ar+Ar+ and Ar*+Ar ==> Ar+Ar are put 3.3734e8 and 1807 respectively. Please introduce some references to obtain such data.



1 Reply Last Post Jun 12, 2014, 3:26 p.m. EDT
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Posted: 1 decade ago Jun 12, 2014, 3:26 p.m. EDT
I need some information ... how to use the Comsol Multiphysics Simulator for understanding the electron beam emission from the plasma focus device.
for example, i have pasted a Abstract of a paper to get information, how to apply for my experimental data via this simulator; how may i apply for my work via this way:
"
COMSOL Aided Design of an Extraction Pipe for the
Electron Beam From a Plasma Focus Device
M. Valentinuzzi1, E. Ceccolini1, D. Mostacci1, M. Sumini1, F. Rocchi2
1Montecuccolino Nuclear Engeneering Laboratory, University of Bologna, Bologna, Italy
2UTFISSM-PRONOC, ENEA, Bologna, Italy
Abstract
Introduction: The electron beam emitted backward by Plasma Focus devices is being investigated as a radiation source for IORT (Intra-Operative Radiation Therapy) applications [1]. A Plasma Focus device is being developed to this aim. The electron beam is driven through an electron pipe made of stainless steel to impinge on a 50 μm brass foil, where conversion X-rays are generated [2]. Use of COMSOL Multiphysics: Electromagnetic forces in the Plasma Focus device have to be investigated to understand their influence on the electron beam produced by the extraction tube (Figure 1). The peculiarity of the phenomenon is related to the time scale involved, of the order of microseconds, requiring the capability of EM field analysis with frequencies around 100 kHz. Different materials for the extraction tube have to be investigated for clinical applications, to determine the optimum material under two constraints: metal tubes are barred by electrical safety reasons, and on the other hand shielding of the beam against the electromagnetic field is needed to prevent undesired deflections of the electrons. The AC/DC Module in COMSOL is being used to simulate the electromagnetic field in the extraction tube to determine the optimum material. Results: For different frequencies and different materials, graphs of the magnetic field norm vs the z-coordinate have been extracted using COMSOL's Cut Line feature. These graphs (Figure 2) show that at working frequencies (100 kHz-1 MHz) the magnetic field cannot penetrate in the extraction tube zone (from 0 to 100 mm) when the material used is stainless steel or stainless steel covered by a delrin coating, while a full delrin tube is permeable to the magnetic field. Conclusion: When using an extraction tube made of delrin, the magnetic field can penetrate the tube walls modifying the trajectory of the electron beam and thus making it impossible to generate X-rays. On the other hand, using stainless steel as material, the electron beam trajectory is unaltered; however metal surfaces cannot be brought in contact with human tissues, especially in radiotherapy applications. For this reason a delrin coating has been developed to surround the extraction tube.
:

i hope, you will help me about this issue or will you guide me how to use COMSOL for my results.
best regards
Muhammad Zubair Khan
I need some information ... how to use the Comsol Multiphysics Simulator for understanding the electron beam emission from the plasma focus device. for example, i have pasted a Abstract of a paper to get information, how to apply for my experimental data via this simulator; how may i apply for my work via this way: " COMSOL Aided Design of an Extraction Pipe for the Electron Beam From a Plasma Focus Device M. Valentinuzzi1, E. Ceccolini1, D. Mostacci1, M. Sumini1, F. Rocchi2 1Montecuccolino Nuclear Engeneering Laboratory, University of Bologna, Bologna, Italy 2UTFISSM-PRONOC, ENEA, Bologna, Italy Abstract Introduction: The electron beam emitted backward by Plasma Focus devices is being investigated as a radiation source for IORT (Intra-Operative Radiation Therapy) applications [1]. A Plasma Focus device is being developed to this aim. The electron beam is driven through an electron pipe made of stainless steel to impinge on a 50 μm brass foil, where conversion X-rays are generated [2]. Use of COMSOL Multiphysics: Electromagnetic forces in the Plasma Focus device have to be investigated to understand their influence on the electron beam produced by the extraction tube (Figure 1). The peculiarity of the phenomenon is related to the time scale involved, of the order of microseconds, requiring the capability of EM field analysis with frequencies around 100 kHz. Different materials for the extraction tube have to be investigated for clinical applications, to determine the optimum material under two constraints: metal tubes are barred by electrical safety reasons, and on the other hand shielding of the beam against the electromagnetic field is needed to prevent undesired deflections of the electrons. The AC/DC Module in COMSOL is being used to simulate the electromagnetic field in the extraction tube to determine the optimum material. Results: For different frequencies and different materials, graphs of the magnetic field norm vs the z-coordinate have been extracted using COMSOL's Cut Line feature. These graphs (Figure 2) show that at working frequencies (100 kHz-1 MHz) the magnetic field cannot penetrate in the extraction tube zone (from 0 to 100 mm) when the material used is stainless steel or stainless steel covered by a delrin coating, while a full delrin tube is permeable to the magnetic field. Conclusion: When using an extraction tube made of delrin, the magnetic field can penetrate the tube walls modifying the trajectory of the electron beam and thus making it impossible to generate X-rays. On the other hand, using stainless steel as material, the electron beam trajectory is unaltered; however metal surfaces cannot be brought in contact with human tissues, especially in radiotherapy applications. For this reason a delrin coating has been developed to surround the extraction tube. : i hope, you will help me about this issue or will you guide me how to use COMSOL for my results. best regards Muhammad Zubair Khan

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