Alpha spectroscopy

DOE. 1995a. Assays and screening of alpha contaminated soils using low-resolution alpha spectroscopy of thick soil samples. Washington, DC U.S. Department of Energy. NTIS/DE95008969. 

The radon in the air i/as measured continuously by electroprecipitation of the positively charged Po-218 ions in an electric field (10 kV) on a surface barrier detector (Porstendorfer, et al., 1980). For this purpose the air i/as dried, filtered and sucked into an aluminium sphere ( 2 1) with a flowrate of 0.5 lmin-1. The counts due to Po-218 and Po-214 were proportional to the radon activity concentration. Their disintegrations were directly detected by alpha spectroscopy with an energy resolution of about 80 keV. The monitor could detect down to 5 Bq m 3 with a two hour counting time and 30 % statistical accuracy. 

Reineking, A. and J. Porstendorfer, High-volume Screen Diffusion Batteries and the Alpha Spectroscopy for Measurements of the Radon Daughter Activity Size Distributions in the Environment, J. of Aerosol Science 17 (1986) (accepted for publication). 

The aerodynamic size distributions of Pb-214, Pb-212, Pb-210, Be-7, P-32, S-35-SoJ , and stable SO4 were measured using cascade impactors. Pb-212 and Pb-214, measured by alpha spectroscopy, were largely associated with aerosols small than 0.52 11m. Based on over 46 low-pressure impactor measurements, the mean activity median aerodynamic diameter (AMAD) of Pb-212 was found to be 0.13 11m, while for Pb-214 the AMAD was larger—0.16 lim. The slightly larger size of Pb-214, confirmed with operationally different impactors, was attributed to a-recoil-driven redistribution of Pb-214 following decay of aerosol-associated Po-218. A recoil model was presented that explained this redistribution. Low-pressure impactor measurements indicated that the mass median aerodynamic diameter of SoJ ... 

Radioactive plutonium isotopes emit alpha particles. The amount of radioactive plutonium in a sample can be measured by alpha spectroscopy, a technique for counting the alpha radiation. The technique is used at the Los Alamos National Laboratory (LANL) in New Mexico in order to monitor employees for exposure. 

Sample preparation is rather involved. A sample of urine or fecal matter is obtained and treated with calcium phosphate to precipitate the plutonium from solution. This mixture is then centrifuged, and the solids that separate are dissolved in 8 M nitric acid and heated to convert the plutonium to the +4 oxidation state. This nitric acid solution is passed through an anion exchange column, and the plutonium is eluted from the column with a hydrochloric-hydroiodic acid solution. The solution is evaporated to dryness, and the sample is redissolved in a sodium sulfate solution and electroplated onto a stainless steel planchette. The alpha particles emitted from this electroplated material are measured by the alpha spectroscopy system, and the quantity of radioactive plutonium ingested is calculated. Approximately 2000 samples per year are prepared for alpha spectroscopy analysis. The work is performed in a clean room environment like that described in Workplace Scene 1.2. 

Stephanie Boone, a technician at Los Alamos National Laboratory, Chemistry Division Bioassay Program, prepares samples to be electroplated for alpha spectroscopy analysis. The hair net and special lab coat are required for a clean room environment. 

The electrodeposition of uranium as an oxide is routinely employed as a means of preparing sources for quantitative analytical measurement through alpha spectroscopy. Recently dos Santos et al. studied the electrodeposition of uranium with... 

Methods for Determining Biomarkers of Exposure and Effect. As discussed above, the presence of radium in biological materials is usually determined by virtue of its radioactivity. Methods available for the determination of radioactivity in biological materials include alpha spectroscopy and gamma spectrometry, which is more convenient, but generally less sensitive, than alpha spectroscopy (Joshi 1987). It would be useful to have additional data on the sensitivity and accuracy of the methods that are currently in use. 

Keller, G., Folkerts, K.H. Muth, H. (1982) Methods for the determination of222Rn (radon) and 220Rn (thoron) exhalation rates using alpha spectroscopy. Radiation Protection Dosimetry, 3, 83-9. 

Automated Ion-exchange Separation Apparatus coupled with the Detection System for Alpha Spectroscopy (AIDA)... 

The basic information in the study of sorption processes is the quantity of substances on the interfaces. In order to measure the sorbed quantity accurately, very sensitive analytical methods have to be applied because the typical amount of particles (atoms, ions, and molecules) on the interfaces is about I0-5 mol/m2. In the case of monolayer sorption, the sorbed quantity is within this range. As the sorbed quantity is defined as the difference between quantities of a given substance in the solution and/or in the solid before and after sorption processes (surface excess concentration, Chapter 1, Section 1.3.1), all methods suitable for the analysis of solid and liquid phases can be applied here, too. These methods have been discussed in Sections 4.1 and 4.2. In addition, radioisotopic tracer method can also be applied for the accurate measurement of the sorbed quantities. On the basis of the radiation properties of the available isotopes, gamma and beta spectroscopy can be used as an analytical method. Alpha spectroscopy may also be used, if needed however, it necessitates more complicated techniques and sample preparation due to the significant absorption of alpha radiation. The sensitivity of radioisotopic labeling depends on the half-life of the isotopes. With isotopes having medium half-time (days-years), 10 14-10-10 mol can be measured easily. 

The excretion of uranium in fecal material results primarily from intakes by ingeshon, and includes uranium swallowed after inhalation. Usually, uranium will appear in feces within hours after intake thus providing a rapid means of determining whether an intake has occurred. Fecal analysis requires prechemistry preparation that includes ashing of the sample, cleaning by co-precipitation, and solvent extraction followed by electrodeposition. Alpha spectroscopy is then performed (Singh and Wrenn 1988). Urinalysis is typically favored over both fecal and blood analysis because it is generally more sensitive and less costly, and because fecal analysis provides no uptake or retention information and blood analyses is invasive. 

Singh and Wrenn (1988) describe a method for uranium isotopic analysis of air filters. Air filters are ashed, redissolved, and co-precipitated with iron hydroxide and calcium oxalate. The uranium is further purified by solvent extraction and electrodeposition. An alpha spectroscopy detection level of 0.02 dpm/L for in solution was reported (Singh and Wrenn 1988). 

The EPA developed two methods for the radiochemical analysis of uranium in soils, vegetation, ores, and biota, using the equipment described above. The first is a fusion method in which the sample is ashed, the silica volatilized, the sample fused with potassium fluoride and pyrosulphate, a tracer is added, and the uranium extracted with triisooctylamine, purified on an anion exchange column, coprecipitated with lanthanum, filtered, and prepared in a planchet. Individual uranium isotopes are separately quantified by high resolution alpha spectroscopy and the sample concentration calculated using the yield. The second is a nonfusion method in which the sample is ashed, the siUca volatilized, a tracer added, and the uranium extracted with triisooctylamine, stripped with nitric acid, co-precipitated with lanthanum, transferred to a planchet, and analyzed in the same way by high resolution a-spectroscopy (EPA 1984). 

C26.05.01 C1001-90(1995)el Standard Test Method for Radiochemical Determination of Plutonium in Soil by Alpha Spectroscopy... 

Dienstbach, F. and Bachmann, K. 1980. Determination of plutonium in soil by gas chromatographic separation and alpha spectroscopy. Anal Chem 52, 62624. 

The alpha activity of uranium in soil samples from Slovakia was determined after a relatively simple sample preparation procedure (Donoval and Matel 2001). The soil samples were dried, ground, and ashed at 550°C, leached with HNO3 + HCl and HNO3 + HF. This was followed by solvent extraction, chromatographic separation of uranium from thorium, deposition with NdFj and alpha spectroscopy for the determination of the 238U/234U ratio. 

Amoli, H.S., Barker, J., and Flowers, A. (2007). Closed vessels microwave digestion method for uranium analysis of soils using alpha spectroscopy, J. Radioanal. Nucl. Chem. TTi. 281-284. 

Andreou, G., Efstathiou, M., and PashaUdis, I. (2012). A simplified determination of uranium in phosphate rock and phosphogypsum by alpha spectroscopy after its separation by liquid-extraction, J. Radioanal. Chem. 291, 865-867. 

Charalamhous, C., Aletrari, M., Piera, P. et al. (2013). Uranium levels in Cypriot groundwater samples determined hy ICP-MS and alpha-spectroscopy, J. Environ. Radioact. 116, 187-192. 

FIGURE 4.10 Outline of radiochemical separation processes used to prepare uranium bioassay samples for alpha spectroscopy. (Adapted from training manual IAEA, Determination of Uranium in Urine by Alpha Spectroscopy, IAEA, Vienna, Austria, 2000.)... 

IAEA. (2000). Determination of uranium in urine by alpha spectroscopy. Vienna, Anstria IAEA. 

Estimated activity Dose rate (a,p,y,n) Surface contamination Visual inspection Radiography Weight, density Dimensions Optical microscopy Fingerprints fibers Gamma spectroscopy Alpha spectroscopy... 

Alpha spectroscopy is a more selective technique, since alpha particles are emitted with characteristic energies, which facilitate simultaneous determination of alpha radionuclides with good-quality energy resolution. Therefore it could be used directly as detection technique for some alpha radionuclides. Nevertheless, various alpha emitters can be affected by the presence of spectral interferences, e.g. " Am/ Pu and and by auto-absorption effects, requiring carefiil... 

These in-beam techniques are well established as sensitive tools in their own right and, when used for structure studies in superheavy nuclei, are generally complementary to decay studies following alpha or beta decay. In this section we will first look at the experimental conditions for in-beam gamma and electron spectroscopy, before discussing alpha spectroscopy and gamma spectroscopy after alpha decay. 

Radionuclide activities (Bq/k determined gamma spectroscopy ( Pb, Cs), alpha spectroscopy f U) and ICP-MS in the... 

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