Authors:M. Cooper, P. Burns, B. Tracy, M. Wilks, and G. Williams
Re-suspension studies on soils contaminated with plutonium during nuclear weapons tests were performed by use of a mechanical dust-raising apparatus. Airborne dust was analyzed in terms of mass and241Am activities for particle sizes less than 7 m. The AMAD was determined as 4.8 to 6 m, for re-suspended soil. Also, surface soil was characterized in the laboratory by means of sieving and microparticle classification, yielding mass and241Am activity distributions with respect to size. Data indicate the granularity of plutonium contamination at both major and minor trial sites. Depth profile analyses for undisturbed, areas demonstrate that most (74% on average) of the americium and plutonium activity is found in the top 10 mm of soil. Plutonium and americium activities were found to be enhanced in the inhalable fraction over their values, in the total soil, and the enhancement factors were similar in re-suspended dust and surface soil. Observed enhancement factors ranged from 3.7 to 32.5.
Authors:P. Kudějová, Th. Materna, J. Jolie, A. Türler, P. Wilk, S. Baechler, Zs. Kasztovszky, Zs. Révay, and T. Belgya
A new flexible prompt gamma-ray activation analysis (PGAA) station will be installed and operated at the FRM-II reactor in Garching at the beginning of the year 2006. The PGAA station has been moved from the Paul Scherrer Institute (PSI), Villigen, Switzerland and is now being re-designed for three different experimental applications: PGAA instrument, cold neutron tomography setup and a compact Ge-array. Simulations of the beam guide have been carried out in order to yield the best conditions for each of the instruments, and are discussed here. A number of the PGAA applications are listed here. A new project dealing with a systematic measurement of bulky composition of small amount of meteorites (~100 mg) is proposed. Results of a test measurement of the Dhurmasala meteorite composition at the PGAA station at the Budapest Research Reactor are presented. Expected parameters of the PGAA facility at FRM-II are compared both with those at PSI and with the Budapest facility.
Authors:P. Wilk, J. Landrum, D. Shaughnessy, J. Kenneally, N. Stoyer, M. Stoyer, K. Moody, N. Aksenov, G. Bozhikov, E. Tereshatov, G. Vostokin, S. Shishkin, and S. Dmitriev
A chemical separation method based on reversed-phase chromatography has been developed to separate the group five elements
from the reaction products produced in the bombardment of 243Am with 48Ca ions. Decontamination factors on the order of 106 were achieved for group-three elements such as americium, and 107 or more for selected reaction products as measured by gamma-ray spectrometry pre-and post-chemistry. Details of the chemical
separation scheme are discussed and compared to previously reported results.
Authors:B. Wierczinski, K. Gregorich, B. Kadkhodayan, D. Lee, L. Beauvais, M. Hendricks, C. Kacher, M. Lane, D. Keeney-Shaughnessy, N. Stoyer, D. Strellis, E. Sylwester, P. Wilk, D. Hoffman, R. Malmbeck, G. Skarnemark, J. Alstad, J. Omtvedt, K. Eberhardt, M. Mendel, A. Nähler, and N. Trautmann
Subsecond 224 Pa (T1/2 = 0.85 s) was produced via the 209 Bi(18 O,3n)224 Pa reaction at the 88 inch cyclotron at the Lawrence Berkeley National Laboratory. After production it was transported via a gas-jet system to the centrifuge system SISAK 3. Following on-line extraction with trioctylamine/scintillation solutions from 1M lactic acid, 224 Pa was detected applying on-line -liquid scintillation counting. Unambiguous identification was achieved using time-correlated --decay chain analysis. This constitutes the first chemical on-line separation and detection of a subsecond -decaying nuclide, 0.85-s 224 Pa with the fast extraction system SISAK 3.