Electron beam current in high power cylindrical diode

Roy, Amitava; Menon, R.; Mitra, S.; Sharma, Vishnu; Singh, S. K.; Nagesh, K. V.; Chakravarthy, D. P.
January 2010
Physics of Plasmas;Jan2010, Vol. 17 Issue 1, p013103
Academic Journal
Intense electron beam generation studies were carried out in high power cylindrical diode to investigate the effect of the accelerating gap and diode voltage on the electron beam current. The diode voltage has been varied from 130 to 356 kV, whereas the current density has been varied from 87 to 391 A/cm2 with 100 ns pulse duration. The experimentally obtained electron beam current in the cylindrical diode has been compared with the Langmuir–Blodgett law. It was found that the diode current can be explained by a model of anode and cathode plasma expanding toward each other. However, the diode voltage and current do not follow the bipolar space-charge limited flow model. It was also found that initially only a part of the cathode take part in the emission process. The plasma expands at 4.2 cm/μs for 1.7 cm anode-cathode gap and the plasma velocity decreases for smaller gaps. The electrode plasma expansion velocity of the cylindrical diode is much smaller as compared with the planar diode for the same accelerating gap and diode voltage. Therefore, much higher voltage can be obtained for the cylindrical diodes as compared with the planar diodes for the same accelerating gap.


Related Articles

  • Temperature-dependent resistance changes in invar alloy nanocontact. Xu, P.; Xia, K.; Yang, H. F.; Li, J. J.; Gu, C. Z. // Applied Physics Letters;1/16/2006, Vol. 88 Issue 3, p033108 

    A nanocontact structure of invar alloy is fabricated by using electron beam lithography and lift-off technique. The current-voltage (I-V) characteristic is measured under various temperatures from 10 to 300 K. We find that the I-V curves are nonlinear and asymmetric, and the resistance change...

  • Generation and measurement of subnanosecond electron beams in gas-filled diodes. Tarasenko, V. F.; Rybka, D. V.; Baksht, E. Kh.; Kostyrya, I. D.; Lomaev, M. I. // Instruments & Experimental Techniques;Mar2008, Vol. 51 Issue 2, p213 

    The results of experimental studies of generation of supershort avalanche electron beams (SAEBs) in gas-filled diodes and the analysis of the techniques for measurements of their amplitude-time characteristics are presented. The optimal conditions for obtaining the maximum SAEB amplitudes are...

  • Intense relativistic electron beam generation and prepulse effect in high power cylindrical diode. Roy, Amitava; Menon, R.; Mitra, S.; Kumar, D. D. P.; Kumar, Senthil; Sharma, Archana; Mittal, K. C.; Nagesh, K. V.; Chakravarthy, D. P. // Journal of Applied Physics;Jan2008, Vol. 103 Issue 1, p014905 

    Intense gigawatt relativistic electron beam has been generated in a high power cylindrical diode in the presence of prepulse. A bipolar prepulse voltage, recorded at the diode, varies both in amplitude and time duration with the Marx generator voltage. It was found that only at the accelerating...

  • Perveance of a planar diode with a multipoint cathode. Pushkarev, A. I. // Technical Physics;Mar2008, Vol. 53 Issue 3, p363 

    The I–V characteristics of a planar diode with a multipoint explosive emission cathode are studied under the conditions when the impedance of the diode is matched to the output resistance of the nanosecond generator. The experiments are carried out on the TÉU-500 (350–500 keV,...

  • Efficiency of a planar diode with an explosive emission cathode under the conditions of delayed plasma formation. Pushkarev, A. I.; Novoselov, Yu. N.; Sazonov, R. V. // Technical Physics;Mar2008, Vol. 53 Issue 3, p357 

    The energy and current balances in the diode unit of a high-current pulsed electron accelerator (350–500 keV, 60 ns, 250 J per pulse) are compared for an explosive emission cathode (made of graphite, copper, or carbon felt) and a multipoint (graphite or copper) cathode. The planar diode...

  • Single-charge devices with ultrasmall Nb/AlOx/Nb trilayer Josephson junctions. Dolata, R.; Scherer, H.; Zorin, A. B.; Niemeyer, J. // Journal of Applied Physics;3/1/2005, Vol. 97 Issue 5, p054501 

    Josephson junction transistors and 50-junction arrays with linear junction dimensions from 200 nm down to 70 nm were fabricated from standard Nb/AlOx/Nb trilayers. The fabrication process includes electron beam lithography, dry etching, anodization, and planarization by chemical-mechanical...

  • Field dependence of the carrier injection mechanisms in InGaN Quantum wells: Its effect on the luminescence properties of blue light emitting diodes. Rossi, F.; Salviati, G.; Pavesi, M.; Manfredi, M.; Meneghini, M.; Zanoni, E.; Zehnder, U. // Journal of Applied Physics;May2008, Vol. 103 Issue 9, p093504 

    Carrier injection and radiative recombination processes in InGaN/GaN blue light emitting diodes are investigated by bias-dependent cathodoluminescence. The samples are designed with a single-quantum-well (SQW) light emitter and an adjacent multi-quantum-well (MQW) carrier injector of lower In...

  • EVALUATION OF THE EDR-2 FILM FOR RELATIVE DOSIMETRY OF HIGH-ENERGY PHOTON AND ELECTRON BEAMS. Ahmad, Munir; Zhe Chen; Haijun Song; Jun Deng; Nath, Ravinder // Radiation Protection Dosimetry;2006, Vol. 120 Issue 1-4, p159 

    A sensitometric study of Kodak XV and EDR-2 radiographic films (Eastman Kodak Company, Rochester, NY) was performed using photons ranging from 75 kV to 18 MV and electrons ranging from 6 to 20 MeV. To investigate the applicability of the EDR-2 film for clinical radiation dosimetry, percentage...

  • Emission of an intense large area electron beam from a slab of porous dielectric. Friedman, M.; Myers, M.; Hegeler, F.; Swanekamp, S. B.; Wolford, M. F.; Sethian, J. D.; Ludeking, L. // Journal of Applied Physics;12/15/2004, Vol. 96 Issue 12, p7714 

    Inserting a thick slab of porous dielectric (e.g., ceramic honeycomb) in front of the emitting surface of a large-area planar diode improves the electron beam emission uniformity, decreases the beam current rise and fall times, and maintains a more constant diode impedance. Particle-in-cell...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics