Plasma-Filled Diode for High Dose-Rate Bremsstrahlung

Weber, B.V.; Hinshelwood, D.D.; Murphy, D.P.; Stephanakis, S. J.; Harper-Slaboszewicz, Victor Jozef

doi:10.1109/tps.2004.835945

Cited by 23 publications

(8 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 The intense electron beam is generated from the cold cathode by explosive electron emission 3 ͑EEE͒ process, and the electron emission occurs from the plasma which is formed on the cathode surface when the strong electric field E Ն 10 7 V / cm is applied to the anode-cathode ͑AK͒ gap. The electric field then extracts a space charge limited electron flow from this plasma.…”

Section: Introductionmentioning

confidence: 99%

Shot to shot variation in perveance of the explosive emission electron beam diode

et al. 2009

View full text Add to dashboard Cite

The shot to shot variation in perveance of a planar diode with explosive emission graphite cathode in a range of accelerating gaps 3–12 mm is investigated experimentally. The typical electron beam parameters were 200 kV, 12 kA, 100 ns, with a few hundreds of A/cm2 current density. The diode perveance remains less than the Child–Langmuir value, indicating that only a fraction of the cathode take part in the emission process. A simple statistical analysis of the diode perveance shows that the shot to shot variation is more pronounced for the later part of the accelerating pulse. The cathode plasma expansion velocity and the effective initial emission area have been calculated from the perveance data. It was found that the plasma expansion velocity varies from 3 to 6.5 cm/μs. The mean expansion velocity and the standard deviation increase with the increase in the accelerating gap. The initial emission areas also varies randomly on a shot to shot basis and at the beginning of the accelerating pulse only 4%–35% of the cathode area take part in the emission process. The mean initial emission area and the standard deviation also increase with the increase in the accelerating gap. Experimental result indicates that the larger gaps and lower electric fields suggest a path to more uniform emission.

show abstract

Section: Introductionmentioning

confidence: 99%

Shot to shot variation in perveance of the explosive emission electron beam diode

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Experiments on the Gamble II generator with a planar diode for the negative polarity of the central conductor [9] and with a coaxial diode with a rod-type central electrode of the positive polarity [10] confirm the possibility of increasing the current density and, hence, the power of bremsstrahlung. The Gamble II generator is based on an intermediate storage line with a liquid dielectric, which ensures the short current rise time (∼50 ns) in the low-resistance phase of the diode.…”

Section: Introductionmentioning

confidence: 82%

Power Increase of the Electron Source Based on the Plasma-Filled Diode

Zherlitsyn

Kovalchuk

Pedin

2015

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

The technique of a linear transformer driver (LTD) now allows building the generators of high-power nanosecond pulses with the current rise time of ∼100 ns without intermediate power compression stages. This technique is being examined for use in high-current high-voltage electron sources based on plasma-filled diodes. The power of a plasma-filled diode is determined by the driving circuit parameters and the transition diode resistance. The problem of power rise can be solved by increasing the stored energy in the circuit inductance provided that the diode resistance rise rate is constant. In experiments on the LTD (53 nF, 480 kV), the possibility has been checked out for such increase in the stored energy. A current increase from 50 to 180 kA was obtained by increasing the current rise rate from 0.4 to 1.9 kA/ns. Stored energy has been increased, respectively, from 0.2 to 3.6 kJ. The time of energy transfer into the circuit inductance was about 120-140 ns. Maintaining the diode resistance rise rate at 0.5 /ns has been shown. Diode power has been increased up to 170 GW. Further increase in power of the plasma-filled diode has been obtained using simulation circuit of the Megavolt (MV) range LTD. To simulate such a linear transformer, the driver circuit was made as Marx generator with coaxial water line (5.3 , 56 ns, and 1.5 MV), providing a current input of 160 kA into the 550-nH inductance in 120 ns. Stored energy in the inductance was about 7 kJ. The following diode parameters were obtained: 150 kA, 1.9 MV, and 250 GW at a resistance rise rate more than 0.5 /ns. The experiments prove that the resistance rise rate of the plasma-filled diode is constant on increasing the stored energy in the inductance up to 7 kJ. It allows scaling the power of an electron source based on the plasma-filled diode.

show abstract

“…However, magnetic core transformer, which is widely used in the field of high power pulse power, has high coupling coefficient and high energy conversion efficiency (Mesyats et al, 2003;Su et al, 2009). IEBA based on Tesla transformer has been used in many fields, such as high power microwave driven (Miller et al, 1975;Weber et al, 1993;Tarasenko et al, 2005), X-ray radiography (Weber et al, 2008), and radiation effects testing (Weber et al, 2004) and so on.…”

Section: Introdutionmentioning

confidence: 99%

Study of low impedance intense electron-beam accelerator based on magnetic core Tesla transformer

Liu¹,

Zhang²,

Yang³

et al. 2012

Laser Part. Beams

View full text Add to dashboard Cite

An intense electron-beam accelerator, which consists of a primary storage capacitor system, a magnetic core Tesla transformer, Blumlein pulse forming line of water dielectric, and a field-emission diode, are constructed and described. The experimental results show that the output voltage of transformer is more than 740 kV, the rise time is about 5 μs, the diode voltage is about 596 kV, electron beam current is about 60 kA, the duration is about 100 ns, and the power is 36 GW when charging voltage is 40 kV. It was suitable to drive magnetically insulated transmission line oscillator. And it can be also used in materials surface modification. This accelerator is very compact and works stably and reliably.

show abstract

Plasma-Filled Diode for High Dose-Rate Bremsstrahlung

Cited by 23 publications

References 16 publications

Shot to shot variation in perveance of the explosive emission electron beam diode

Shot to shot variation in perveance of the explosive emission electron beam diode

Power Increase of the Electron Source Based on the Plasma-Filled Diode

Study of low impedance intense electron-beam accelerator based on magnetic core Tesla transformer

Contact Info

Product

Resources

About