scholarly journals The influence of magnetic field on the ion beam current of Calutron ion source

2018 ◽  
Author(s):  
Jinwen Cao ◽  
Xiuyan Ren ◽  
Ziqiang Zeng ◽  
Guobao Wang
Keyword(s):  
Magnetic Field ◽  
Ion Beam ◽  
Beam Current ◽  
Ion Source

Response to “Comment on `Effects of magnetic field gradient on ion beam current in cylindrical Hall ion source' '' [J. Appl. Phys. 104, 066102 (2008)]

2008 ◽  
Vol 104 (6) ◽  
pp. 066103
Author(s):  
Deli Tang ◽  
Jie Zhao ◽  
Lisheng Wang ◽  
Shihao Pu ◽  
Changming Cheng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Gradient ◽  
Ion Beam ◽  
Magnetic Field Gradient ◽  
Beam Current ◽  
Ion Source

Effects of magnetic field gradient on ion beam current in cylindrical Hall ion source

2007 ◽  
Vol 102 (12) ◽  
pp. 123305 ◽  
Author(s):  
Deli Tang ◽  
Jie Zhao ◽  
Lisheng Wang ◽  
Shihao Pu ◽  
Changming Cheng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Gradient ◽  
Ion Beam ◽  
Magnetic Field Gradient ◽  
Beam Current ◽  
Ion Source

Alloy surface composition resulting from fabrication, as determined by s.i.m.s. (secondary ion mass spectrometry)

1980 ◽  
Vol 295 (1413) ◽  
pp. 134-135
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Surface Composition ◽  
Ion Beam ◽  
Sample Surface ◽  
Beam Current ◽  
Ion Source ◽  
Beam Current Density ◽  
Dynamic Mode ◽  
Static Mode ◽  
Subsequent Performance

In s.i.m.s. the sample surface is ion bombarded and the emitted secondary ions are mass analysed. When used in the static mode with very low primary ion beam current densities (10 -11 A/mm 2 ), the technique analyses the outermost atomic layers with the following advantages (Benninghoven 1973, I975): the structural—chemical nature of the surface may be deduced from the masses of the ejected ionized clusters of atoms; detection of hydrogen and its compounds is possible; sensitivity is extremely high (10 -6 monolayer) for a number of elements. Composition profiles are obtained by increasing the primary beam current density (dynamic mode) or by combining the technique in the static mode with ion beam machining with a separate, more powerful ion source. The application of static s.i.m.s. in metallurgy has been explored by analysing a variety of alloy surfaces after fabrication procedures in relation to surface quality and subsequent performance. In a copper—silver eutectic alloy braze it was found that the composition of the solid surface depended markedly on its pretreatment. Generally there was a surface enrichment of copper relative to silver in melting processes while sawing and polishing enriched the surface in silver

scholarly journals Developing Ultra Small-Scale Radiocarbon Sample Measurement at the University of Tokyo

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 310-318 ◽  
Author(s):  
Yusuke Yokoyama ◽  
Mamito Koizumi ◽  
Hiroyuki Matsuzaki ◽  
Yosuke Miyairi ◽  
Naohiko Ohkouchi
Keyword(s):  
Ion Beam ◽  
Measurement Techniques ◽  
Beam Current ◽  
Ion Source ◽  
Small Samples ◽  
Small Scale ◽  
Target Holder ◽  
Vacuum Line ◽  
The Difference ◽  
Beam Currents

We have developed accelerator mass spectrometry (AMS) measurement techniques for ultra small-size samples ranging from 0.01 to 0.10 mg C with a new type of MC-SNICS ion source system. We can generate 4 times higher ion beam current intensity for ultra-small samples by optimization of graphite position in the target holder with the new ionizer geometry. CO2 gas graphitized in the newly developed vacuum line is pressed to a depth of 1.5 mm from the front of the target holder. This is much deeper than the previous position at 0.35 mm depth. We measured 12C4+ beam currents generated by small standards and ion beam currents (15–30 μA) from the targets in optimized position, lasting 20 min for 0.01 mg C and 65 min for 0.10 mg C. We observed that the measured 14C/12C ratios are unaffected by the difference of ion beam currents ranging from 5 to 30 μA, enabling measurement of ultra-small samples with high precision. Examination of the background samples revealed 1.1 μg of modern and 1 μg of dead carbon contaminations during target graphite preparation. We make corrections for the contamination from both the modern and background components. Reduction of the contamination is necessary for conducting more accurate measurement.

Super-ion-beam accelerator for the ignition of thermonuclear reactions

1980 ◽  
Vol 24 (1) ◽  
pp. 1-14 ◽  
Author(s):  
F. Winterberg
Keyword(s):  
Magnetic Field ◽  
Ion Beam ◽  
Beam Current ◽  
Ion Beams ◽  
Beam Power ◽  
Thermonuclear Reactions ◽  
Beam Voltage ◽  
Multi Stage ◽  
Light Ions ◽  
Thermonuclear Target

A pulsed, multi-stage, high-voltage accelerator is proposed which should be capable of producing intense ion beams of many million amperes and many million volts. Super ion beams produced by this type of accelerator can exceed the limiting Aifvén current for light ions, typically 107 A, at which beam pinching occurs. The beam pinching of these super-beams permits them to be precisely focused onto a thermonuclear target. With such an accelerator it seems to be possible to reach a beam voltage of 108 V with a beam current of 107 A. The resulting beam power of 1015 W should be more than sufficient to ignite a DT thermonuclear microexplosion. By the formation of a stable ion beam superpinch within a thermonuclear target, such a large beam power in conjunction with the strong self-magnetic field of the beam may even lead to the ignition of the DD and perhaps HB11 thermonuclear reactions.

FABRICATION AND MODELING OF MICROCHANNEL MILLING USING FOCUSED ION BEAM

2003 ◽  
Vol 02 (04n05) ◽  
pp. 375-379 ◽  
Author(s):  
A. A. TSENG ◽  
B. LEELADHARAN ◽  
B. LI ◽  
I. INSUA ◽  
C. D. CHEN
Keyword(s):  
Numerical Model ◽  
Silicon Wafer ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Current ◽  
Ion Source ◽  
Experimental Measurements ◽  
Model Predictions

The capability of using Focused Ion Beam (FIB) for milling microchannels is experimentally and theoretically investigated. Microchannel structures are fabricated by a NanoFab 150 FIB machine, using an Arsenic (As2+) ion source. A beam current of 5 pA at 90 keV accelerating energy is used. Several microchannel patternings are milled at various dwell times at pixel spacing of 14.5 nm on top of a 60 nm gold-coated silicon wafer. An analytical/numerical model is developed to predict the FIB milling behavior. By comparing with the experimental measurements, the model predictions have been demonstrated to be reliable for guiding and controlling the milling processes.

Magnetoresistance Effects in Granular Thin Layers Formed by High Dose Iron Implantation Into Silicon

1997 ◽  
Vol 475 ◽  
Author(s):  
S.P. Wong ◽  
W.Y. Cheung
Keyword(s):  
Magnetic Field ◽  
Current Density ◽  
Beam Current ◽  
Implantation Dose ◽  
Ion Source ◽  
Thin Layers ◽  
Beam Current Density ◽  
High Dose ◽  
Zero Field ◽  
Mr Effect

ABSTRACTHigh dose iron implantation into silicon substrates has been performed with a metal vapor vacuum arc ion source to doses ranging from 5×1016 to 2×1017 cm'2 at various beam current densities. The magnetoresistance (MR) effects in these implanted granular layers were studied at temperatures from 15K to 300K. A positive MR effect, i.e., an increase in the resistance at the presence of a magnetic field, was observed at temperatures lower than about 40K in samples prepared under appropriate implantation conditions. The magnitude of the MR effect, defined as ΔR/Ro ≡ (R(H)-Ro)/Ro where R(H) and Ro denote respectively the resistance value at a magnetic field intensity H and that at zero field, was found to depend not only on the implantation dose but also on the beam current density. This is attributed to the beam heating effect during implantation which affects the formation of the microstructures. The ratio δR/Ro was found to attain high values larger than 400% for some samples at low temperatures. The dependence of the MR effects on temperature, implantation dose, and beam current density will be presented and discussed in conjunction with results of transmission electron microscopy.

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