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RE: Question about low E proton interactions on B, Si, Cu, As, P
Dear Jeffrey,
All I have on the subject is from ICRU Report 49, which deals with stopping
powers for protons. The subject matter is not familiar to me. However, one
uses proton-induced reactions such as (p,gamma), (p, alpha gamma), and
p(p,n) to measure proton energy. These reactions are thus fairly well-known.
Some references cited in the report include:
Madsen, C.B. and Venkateswarlu, P. (1948). "Proton Stopping Power of Solid
Beryllium," Phys. Rev. 74, 6548.
In the study by Madsen, C.B. and Venkateswarlu, P. (1948). "Energy
Straggling of Protons," Phys. Rev. 74, 1782, and they deal with
27Al(p,gamma)28Si at 632, 992, 1261 keV and CaF2, AlCl3, and PbCl2
thin-layer detectors.
Chilton, A.B., Cooper, J.N., and Harris, J.C. (1954). "Stopping Powers of
Various Elements for Protons of Energies from 400 keV to 1050 keV",
Phys.Rev. 93, 413 used a Van de Graaff accelerator using Ni and Cu foils.
D. Semrad appears to be an expert in the area. For example, for the
reactions 11B(p,gamma)12C at 163 keV and 19F(p,alpha gamma)16O at 224 keV,
consult Semrad, D., Bauer, P., Aumayer, F., Huber, P., and Obermann, W.
(1983). "Search for an Influence of the Measuring Method on Stopping Cross
Section Data Near the Maximum," Nucl. Instr. Meth. 218, 811.
For Cu, there is a study by Johansen et al. (1971) that measured the
stopping power of Cu using Cr substrate (characteristic X-ray emission yield
technique) using 20-120 keV protons. Johansen, A., Steenstrup, S., and
Wohlenberg, T. (1971). "Energy Loss of Protons in Thin Films of Carbon,
Aluminum, and Silver," Radiat. Eff. 8, 31.
Kido, Y. and Hioki, T. (1983). "Measurements of energy-loss and straggling
for fast H+ in metals and their compoundsby means of a nuclear reasonant
reaction," Phys. Rev. B 27, 2667 uses aluminum-covered silicon wafers.
I hope that this helps put you on te right track. These should contain
references to some more pertinent information in your case.
Best regards,
Grant Nixon
Radiation Physicist
Physics Department
Ion Technologies
MDS Nordion
447 March Road
Ottawa, ON K2K 1X8
tel. (613) 592-3400 ext. 2869
fax (613) 591-7422
-----Original Message-----
From: Jeffrey Leavey [mailto:leaveyja@us.ibm.com]
Sent: Monday, July 28, 2003 10:54 AM
To: radsafe@list.vanderbilt.edu
Subject: Question about low E proton interactions on B, Si, Cu, As, P
Can anyone point me to some references or know the interaction concerns
with low E protons on semiconductor materials like B, Si, Cu, As, P and
other low Z materials?? My company is looking into using H+ implantation
and there is concern about radiation generation above the normal values for
ion implanters. For example, an implanter manufacturer found 11B(p,g)12C
reaction at happens at >150 KeV and the 12C gamma is high energy. Since
semiconductor implanters regularly use B, boron contamination inside the
tool is a potential source for this reaction. The energy range I'm looking
at is 200 KeV and below - more likely in the 9 - 15 KeV range. This
manufacturer found below 150 KeV the rad levels were at background but
above this value up to 200 KeV the rad levels became about 40x background
(to around 500 uR/hr).
I searched the web for reaction cross section info and didn't find much for
protons and deuterons. Can anyone help with some pointers, info or
experiences? Thanks very much!!
Jeff
--------------------------------------------------------------
Jeff Leavey IBM Corp.
845-892-4595 leaveyja@us.ibm.com
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