Mean-Charge Change upon the Deceleration of Heavy Ions in Matter

Author(s):  
Yu. A. Belkova ◽  
Ya. A. Teplova
Keyword(s):  
1996 ◽  
Vol 14 (4) ◽  
pp. 781-788 ◽  
Author(s):  
O. Boine-Frankenheim ◽  
C. Stöckl

Due to the high nonequilibrium charge states specific to heavy ions, the plasma regime with coupling parameters l/ND < 1 and Zp/ND > 1 (ND ∼ number of electrons in a Debye sphere, Zp mean charge state of the projectile) is of interest for the applications. In this regime the stopping power cannot be obtained by a linearization of the Vlasov-Poisson system, but forcing a fully nonlinear treatment. In the present paper the Vlasov-Poisson system is solved numerically by using the capability of the new generation of massively parallel supercomputers. The results are compared with the standard dielectric theory and a binary collision approach. Charge-state calculations are performed, accounting for all relevant features of the atomic processes and the spectra characteristic to heavy ions in dense plasma targets. The results show good agreement with experimental measurement for medium and heavy ions penetrating a Z-pinch device.


2003 ◽  
Vol 21 (1) ◽  
pp. 7-11 ◽  
Author(s):  
J. HASEGAWA ◽  
N. YOKOYA ◽  
Y. KOBAYASHI ◽  
M. YOSHIDA ◽  
M. KOJIMA ◽  
...  

The interaction process between fast heavy ions and dense plasma was experimentally investigated. We injected 4.3-MeV/u or 6.0-MeV/u iron ions into a z-pinch-discharge helium plasma and measured the energy loss of the ions by the time of flight method. The energy loss of 4.3-MeV/u ions fairly agreed with theoretical prediction when the electron density of the target was on the order of 1018 cm−3. With increasing electron density beyond 1019 cm−3, the difference between the experiment and the theory became remarkable; the experimental energy loss was 15% larger than the theoretical value at the peak density. For 6.0-MeV/u ions, the deviation from the theory appeared even at densities below 1019 cm−3. These discrepancies indicated that density effects such as ladderlike ionization caused the enhancement of the projectile mean charge in the target.


Author(s):  
K. F. Russell ◽  
L. L. Horton

Beams of heavy ions from particle accelerators are used to produce radiation damage in metal alloys. The damaged layer extends several microns below the surface of the specimen with the maximum damage and depth dependent upon the energy of the ions, type of ions, and target material. Using 4 MeV heavy ions from a Van de Graaff accelerator causes peak damage approximately 1 μm below the specimen surface. To study this area, it is necessary to remove a thickness of approximately 1 μm of damaged metal from the surface (referred to as “sectioning“) and to electropolish this region to electron transparency from the unirradiated surface (referred to as “backthinning“). We have developed electropolishing techniques to obtain electron transparent regions at any depth below the surface of a standard TEM disk. These techniques may be applied wherever TEM information is needed at a specific subsurface position.


1989 ◽  
Vol 50 (C2) ◽  
pp. C2-237-C2-243 ◽  
Author(s):  
H. VOIT ◽  
E. NIESCHLER ◽  
B. NEES ◽  
R. SCHMIDT ◽  
CH. SCHOPPMANN ◽  
...  

1979 ◽  
Vol 129 (10) ◽  
pp. 239 ◽  
Author(s):  
I.A. Akhiezer ◽  
L.N. Davidov
Keyword(s):  

2020 ◽  
Author(s):  
Suman Duhan ◽  
Kedar Sahoo ◽  
Sudhir Kumar Singh ◽  
Manoj Kumar

The development of a sensitive alpha-NaYF4:Yb3+, Er3+ solid-phase upconverting platform (UCP) has been realized using Moringa oleifera leaf extract for selective detection of arsenic (As III) contamination in drinking water. The presence of polyphenols in the leaves extract is shown to induce luminescence resonance transfer (LRET), diminishing thereby the Er3+ upconverting red and green emissions activated by 980 nm excitation. However, addition of As3+ species interrupts the LRET process and restores emission proportionately. This feature allows platform to selectively detect arsenic pollution in water below the safe limit of 10 ppt. The uniqueness of UCP lies in monitoring the As3+ contamination in samples containing heavy ions (Cd2+, Hg2+) as well, without apparent effect on the signal reproducibility. UCP is also found to be insensitive to other interfering ions like Pb2+, H2PO4-, F-, Cl-, Ca2+, Mg2+, Sn2+, Cr6+, Fe2+ and Co2+, if present.<br><br>


Author(s):  
G. Bascoul ◽  
K. Sanchez ◽  
G. Perez ◽  
F. Bezerra ◽  
H. Chauvin

Abstract Pulsed laser for radiation sensitivity evaluation has become a common tool used in research and industrial laboratory. This paper aims to highlight an approach to understand weaknesses of a component under radiation environment using a short pulsed width laser beam coupled to thermography technique, heavy ions test inputs and physical analysis. This paper is based on a study of a PWM device embedded on voltage converter.


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