scholarly journals Decreased beam divergence in proof-of-principle experiment for the light ion beam fusion facility PBFA II

1985 ◽  
Vol 3 (1) ◽  
pp. 93-105 ◽  
Author(s):  
J. P. Vandevender ◽  
J. A. Swegle ◽  
D. J. Johnson ◽  
K. W. Bieg ◽  
E. J. T. Burns ◽  
...  
Keyword(s):  
Current Density ◽  
Ion Beam ◽  
Ion Source ◽  
Beam Divergence ◽  
Anode Current Density ◽  
Anode Current ◽  
Lithium Ions ◽  
Short Pulses ◽  
Proof Of Principle

The Proto-I experiment for a proof-of-principle experiment is described resulting in a beam divergence for ions of only 14mrad at 1·5 MV—420 KA operation and 6 KA/cm2 anode current density before focusing. This is a better beam divergence than required for Sandia National Laboratories' PBFA I and II installations, for which scaling is discussed. Ion source development is reported and the PBFA II experiment described for 30 MV operation with short pulses (10–15 nsec) of lithium ions. Pulses of 50 nsec width and 130 KJ energy have been achieved from the prototype module for PBFA II.

Influence of anode current density on carbon parasitic reactions during electrolysis

2021 ◽  
Author(s):  
Tongxiang Ma ◽  
Lang Zhao ◽  
Yu Yang ◽  
Liwen Hu ◽  
Shengfu Zhang ◽  
...  
Keyword(s):  
Current Density ◽  
Anode Current Density ◽  
Anode Current

Analysis of the Effect of Beam Divergence Angle on Back-Streaming Electron Region in Ion Source for EAST-Neutral Beam Injection

2018 ◽  
Vol 4 (3) ◽  
Author(s):  
Hu Chundong ◽  
Wu Mingshan ◽  
Xie Yahong ◽  
Wei Jianglong ◽  
Yu Ling
Keyword(s):  
Ion Beam ◽  
Ion Source ◽  
Neutral Beam Injection ◽  
Beam Divergence ◽  
Neutral Beam ◽  
Divergence Angle ◽  
Beam Extraction ◽  
Beam Injection ◽  
Back Plate ◽  
Beam Divergence Angle

During the process of beam extraction in positive ion source under high voltage region, a large number of electrons are produced in the gaps of grids. After back-streaming acceleration, these electrons go back to arc chamber or impinge grids and then heat back plate or grids, which are harmful for the safety of ion source. Under the situation of poor beam extraction optics, a large part of the primary beam ions bombard the surface of suppressor grid (SG). And this process produces a large number of electrons. Due to the huge extracted voltage, the secondary electron emission coefficient of the SG surface is also high. As a result, the grids' current grows. According to the measurement of the current of SG and the calculation of the perveance of the corresponding shoot, the effect of ion beam divergence angle on back-streaming electrons can be analyzed. When the beam divergence angle increases, the number of back-streaming electrons increases rapidly, and grids' current changes significantly, especially the current of gradient grid and SG. The results can guide the parameters operating on the ion source for Experimental Advanced Superconducting Tokamak-neutral beam injection (EAST-NBI) and find the reasonable operation interval of perveance and to ensure the safety and stable running of the ion source, which has great significance on the development of long pulse, high power ion source.

scholarly journals A new method for investigating conduction phenomena in semi-conductors

1936 ◽  
Vol 157 (890) ◽  
pp. 50-66 ◽  
Keyword(s):  
Current Density ◽  
Unit Volume ◽  
Low Pressure ◽  
Anode Current Density ◽  
Anode Current ◽  
Gas Discharges ◽  
Positive Ions ◽  
Electron Current Density ◽  
The Mean ◽  
The Difference

Langmuir has shown that in low pressure gas discharges, that part of the discharge usually referred to as the positive column consists of equal numbers of positive ions and electrons per unit volume, and to this portion he has given the name “plasma”. He has shown, moreover, that the current passing between cathode and anode is proportional only to the difference between the number of electrons passing in the direction of cathode to anode across 1 sq cm placed normally to the tube axis and the number of electrons passing across the same area in the opposite direction. The random electron current density is usually many times the anode current density. The electrons in the plasma have been shown by Langmuir to have a Maxwellian distribution of velocities and that they can therefore have ascribed to them a mean energy, V e , corresponding to a temperature T where, as in the kinetic theory of gases V e = 3/2 k T (1) or T = 2/3 × 1.59 × 10 -20 /1.37 × 10 -16 × 10 8 Kelvin degrees per volt = 7730°K per volt. In low pressure gas discharges T varies from 5000°K to 30,000°K or the mean energy of electrons expressed in electron volts varies from about 0.5 to 4 volts.

scholarly journals Experiments on intense ion beam formation with inhomogeneous electric field

2021 ◽  
Author(s):  
Sergey Vybin ◽  
V. A. Skalyga ◽  
Ivan Izotov ◽  
Sergey Golubev ◽  
Sergey Razin ◽  
...  
Keyword(s):  
Electric Field ◽  
Current Density ◽  
Microwave Plasma ◽  
Ion Beam ◽  
Plasma Heating ◽  
Ion Source ◽  
Ecr Ion Source ◽  
Inhomogeneous Electric Field ◽  
Beam Formation ◽  
Current Densities

Abstract The high efficiency of a new ion beam extraction system with a strongly inhomogeneous electric field has been experimentally demonstrated. Previously, this approach was proposed and analysed numerically by the authors. The experiment was carried out using a pulsed high-current electron-cyclotron resonance (ECR) ion source SMIS 37 with high frequency (37.5 GHz) and high power (100 kW) microwave plasma heating. The accelerating field strength is increased (when compared to a flat or a quasi-pierced geometry) in the plasma meniscus region due to its inhomogeneity. It allows for the increase of the ion acceleration rate and for expansion of the available range of current densities with effective ion beam formation. The experiment demonstrated the main advantages of this approach, such as: a significant decrease in the optimal accelerating voltage for certain values of current density; a possibility of ion beam formation with previously inaccessible current densities; a significant decrease in the ion flux to the puller in non-optimal modes of ion beam formation. Proton beams with a current density of up to 1.1 A cm-2 were obtained for the first time with an ECR ion source.

Characterization of the Ion Beam Current Density of the RF Ion Source with Flat and Convex Extraction Systems

Silicon ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 2743-2749 ◽  
Author(s):  
Maryam Salehi ◽  
Ali Asghar Zavarian ◽  
Ali Arman ◽  
Fatemeh Hafezi ◽  
Ghasem Amraee Rad ◽  
...  
Keyword(s):  
Current Density ◽  
Ion Beam ◽  
Beam Current ◽  
Ion Source ◽  
Beam Current Density ◽  
Rf Ion Source

Effect of an axial magnetic field and arc current on the anode current density in diffuse vacuum arcs

2016 ◽  
Vol 23 (9) ◽  
pp. 093507 ◽  
Author(s):  
Hui Ma ◽  
Yingsan Geng ◽  
Zhiyuan Liu ◽  
Jianhua Wang ◽  
Zhenxing Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Current Density ◽  
Axial Magnetic Field ◽  
Anode Current Density ◽  
Anode Current ◽  
Arc Current

Effect of baking temperature and anode current density on anode carbon consumption

1996 ◽  
Vol 27 (2) ◽  
pp. 177-183 ◽  
Author(s):  
Z. Kuang ◽  
J. Thonstad ◽  
S. Rolseth ◽  
M. Sørlie
Keyword(s):  
Current Density ◽  
Anode Current Density ◽  
Anode Current ◽  
Carbon Consumption ◽  
Anode Carbon
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