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Abstract  

Various ion beam techniques (E≥1 MeV/amu) are compared from the standpoint of their analytical capabilities: Charged Particle Activation Analysis (CPAA), Particle Induced X-Ray Emission (PIXE), Ion Induced γ-Ray Emission for bulk analysis, Prompt Reaction Analysis (PRA), Rutherford Backscattering Spectrometry for surface layer characterization and ion absorptiometry for microscopic analysis. With CPAA and PIXE≥70 elements can be detected with sub-ppm sensitivity. The scope of CPAA is being extended with heavy ion beams for radioactivation of H, He, Li, Be, B, C isotopes. In surface layer characterization recent developments in PRA and RBS also involve heavy ion beams. In RBS they can significantly enhance mass resolution for M>50 in comparison with α scattering. For example,63Cu and65Cu can be quantitatively identified in surface films using a 1 MeV/amu40Ar beam. In microscopic analysis, the nuclear microprobe can provide atom-specific signals from quantities ≥10−12 g on spots of a diameter ≥2 μm. Ion absorptiometry techniques can sense density variations as low as ±0.5% in 1 μm3 or less of sample volume.

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Professor Richard E. Wainerdi

Presented with the Hevesy Medal for 1977

Journal of Radioanalytical and Nuclear Chemistry
Author: E. Schweikert
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Abstract  

An examination of the literature concerning the determination of cadmium by Prompt Gamma-Ray Neutron Activation Analysis (PGNAA) has been conducted. In-vivo activation analysis of the liver and kidney is the most common application reported and is briefly reviewed here. This review will concentrate on the determination of cadmium in in-vitro systems. These include a number of different complex matrices such as geological, environmental and biological materials, as well as water, sediments, foods and construction material. Nuclear reactors, accelerators, and radioisotopes have all been used as neutron sources with varying degrees of sensitivity.

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Abstract  

The possibility of a simultaneous determination of low and medium Z elements in hair in a single ion beam exposure was studied. Different ion beams, proton, deuteron,3He and18O, at velocities ranging from 2.7–6.9 MeV/amu were investigated. In this work,18 8O4+ beam was found to give the best experimental condition in terms of sensitivity and number of elements detected. The detection limits in a single hair ranged from 2.9·10−5 μg for Fe to 0.72 μg for H using this beam.

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Abstract  

A survey has been made on the application of charged particle activation analysis for the detection of traces of medium Z elements (40≤Z≤58, 72, 74) using protons and deuterons of 20 MeV,3He and4He ions of 40 MeV. The product nuclides considered were γ-ray emitting radioisotopes with half lives ranging from 10 min to 3 days. Based on the thick target yields obtained, proton activation was found to provide an optimum compromise between sensitivity and selectivity.

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Abstract  

The Time-of-Flight (ToF) technique can be used for mass identification, for separation of a specified mass or for measuring the energy of a given mass particle. The instrumentation required is simple and low in cost. The method features high yield, transmission efficiency is typically of 5 to 20%. Even with short flight paths (5 to 10 cm), ToF has adequate mass resolution (M/M 300 to 500) for identifying isotopic species. This paper examines the scope of ToF in nuclear science with examples in mass spectrometry, in mass separation and in kinetic energy measurements of fixed mass particles. An example of the latter is the energy determination of recoil nuclei. If a recoil is produced inside a solid, the residual recoil energy reveals the depth from which it originates. This approach is used for profiling nitrogen via14N(n, p)14C. The ToF measurement of the14C recoil energies reveals the depth distribution of nitrogen with better than 50 Å resolution.

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Abstract  

Reaction yields on thick zirconium targets with proton, deuteron,3He and4He activation have been measured and compared. The most favorable reaction combining high sensitivity and selectivity was found to be Zr(p, xn)90Nb. The absolute cross-section for this excitation function has been measured for proton energies up to 20 MeV. Analytical applications are illustrated with nondestructive zirconium analyses in glass. Yields from the thick target experiments indicate that the detection limit for this zirconium analysis method is ∼1 ppb.

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Abstract  

The reaction103Rh(p, n)103Pd was investigated for the trace detection of Rh. Maximum activation of Rh with minimal interferences was achieved with protons of 11 MeV. The detection limit for the nondestructive assay of Rh is 0.03 ppm.

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Abstract  

A survey is given on the analytical use of X-ray emitting radioisotopes produced by charged particle activation. Thirty-nine proton and deuteron reactions were considered on twentysix elements (34≤Z≤82). Thick target yields and sensitivity estimates are presented. The features and limitations of this method and the scope of non-destructive and destructive determinations are discussed. The main interest of this approach is to open an avenue for trace analysis with simplified data acquisition and reduction.

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Abstract  

Trace analysis methods have been developed for determining thallium, lead and bismuth. Proton or deuteron activation is used followed by a radiochemical separation of the reaction products:203Pb from thallium,206Bi from lead, and207Po from bismuth. Activation curves are presented for different nuclear reactions occuring on the elements studied. Determinations have been carried out on high purity samples containing varying amounts of thallium, lead, and bismuth. Based on experimental data, the detection limits are estimated at 0.01 ppm for lead, and 0.001 ppm for thallium and bismuth, respectively.

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