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Characterization of waste drums using nonintrusive active and passive computed tomography

Description: We have developed a data acquisition scanner for gamma-ray nondestructive assay (NDA) active and passive computed tomography (A&PCT) along with associated computational techniques for image reconstruction, analysis, and display. We are using this scanner to acquire data sets of mock-waste drums at Lawrence Livermore National Laboratory (LLNIL). In this paper, we discuss some issues associated with gamma-ray spectroscopy assay, NDA imaging, describe the design and construction of an NDA drum scanner and report on code development for image reconstruction. We also present representative A&PCT assay results of well characterized mock-waste drums. These preliminary results suggest that A&PCT imaging can be used to produce accurate absolute assays of radioactivity in real-waste drums.
Date: August 1, 1994
Creator: Roberson, G.P.; Martz, H.E.; Decman, D.J.; Camp, D.C.; Azevedo, S.G. & Keto, E.R.
Partner: UNT Libraries Government Documents Department

Gamma ray scanner systems for nondestructive assay of heterogeneous waste barrels

Description: Traditional gamma safeguards measurements have usually been performed using a segmented gamma scanning (SGS) system. The accuracy of this technique relies on the assumption that the sample matrix and the activity are both uniform for a segment. Waste barrels are often highly heterogeneous, span a wide range of composition and matrix type. The primary sources of error are all directly or indirectly related to a non-uniform measurement response associated with unknown radioactive source spatial distribution and heterogeneity of the matrix. These errors can be significantly reduced by some imaging techniques that measure exact spatial locations of sources and attenuation maps. In this paper we describe a joint R&D effort between the Lawrence Livermore National Laboratory (LLNL) and the Institute of Nuclear Techniques (INT) of the Technical University, Budapest, to compare results obtained by two different gamma-ray nondestructive assay (NDA) systems used for imaging waste barrels. The basic principles are the same, but the approaches are different. Key factors to judge the adequacy of a method are the detection limit and the accuracy. Test drums representing waste to be measured are used to determine basic parameters of these techniques.
Date: March 25, 1997
Creator: Martz, H.E.; Decman, B.J.; Roberson, G.P. & Levai, F.
Partner: UNT Libraries Government Documents Department

PHYSICS DIVISION SUMMARY REPORT FOR JULY-AUGUST 1960

Description: In a study of nuclear resonance absorption of gamma rays. calculations were carried out to determine the effect on Zeeman lines of applying a resonant r- f field. Thirty-two gamma rays from Er/sup 161/, produced by (n,2n) and ( gamma .n) reactions. were measured and fitted into a decay scheme. Spin and parity assignments of some levels are indicated. Results from molecular beam studies are presented for Ho/sup 166/ and Ge/sup 71/. In the program for Ar/sup 40/-K/sup 40/ dating of meteorites, a method was developed for pumping down atmospheric cutoffs, Toepler pumps, and other apparatus without carefully matching pumping rates. (For preceding period see ANL6l69. For subsequent period see ANL-62l4.) (W.D.M.)
Date: October 31, 1961
Partner: UNT Libraries Government Documents Department

Pharmacokinetics of Genetically Engineered Antibody Forms Using Positron Emission Tomography

Description: In the last grant period we have focused on multi-step targeting methodologies (MST), as a method for delivery of high dose to the tumor, with low dose to the bone marrow. We have explored uptake in colorectal, pancreatic and prostate cancer, using an special preparation, developed in collaboration with NeoRex A high tumor/bone marrow ratio is clearly achieved with MST, but with a cost, namely the higher dose to normal kidney. For this reason, we have in particular, (a) looked dosimetry for both tumor and normal organ, and especially renal dosimetry, which appears to be the target organ, for Y-90. (b) In parallel with this we have explored the dosimetry of very high dose rate radionuclides, including Holmium-166. (c) In addition, with NaiKong Cheung, we have developed a new MST construct based on the anti-GD2 targeting 5F11; (d) we have successfully completed development of s-factor tables for mice. In summary, renal dosimetry is dominated by about 4-5% of the injected dose being held long-term in the renal cortex, probably in the proximal tubule, due to the universal uptake of small proteins. This appears to be a function of a biotynlated protein binding of the strept-avidin construct, to HSP70. This cortical uptake has caused us to reconsider renal dosimetry as a whole, with the smaller mass of the cortex, rather than the whole kidney, as the target organ. These insights into dosimetry will be of great importance as MST, becomes more common in clinical practice.
Date: August 31, 2004
Creator: Steven M. Larson, M.D. Nai-Kong Cheung, M.D., Ph.D.
Partner: UNT Libraries Government Documents Department

Skeletal remodeling dynamics: New approaches with imaging instrumentation

Description: This report of progress and future objectives timetable is based on an included schematic of goals and objectives and the project abstract which is included as Appendix 1. Five matters are summarized in the order of (1) novel methods of calcified bone confocal microscopy and reconstruction image analysis of decalcified beagle and human cortical bone serial sections, (2) macroscopic cross-correlation of beagle and human cortical and cancellous bone fractions with CT analysis, (3) guidance to the most radiobiologically important skeletal regions of interest with the just completed {sup 90}Sr bone tumor map from life time beagle studies, (4) deposition patterns of radioactive agents that participate in apatite crystal nucleation processes in bone and leave radiation-excited electrons trapped in bone mineral, and (5) the budget period timetable. The discovery that beta particles from {sup 166}Ho (T{sub {1/2}} =26 hr, {beta}{sub max} = 1.8 MeV) phosphonic acid bone agents leave detectable, long-lived, electron paramagnetic resonance signals in bone is included in Appendix 2 as a joint report.
Date: December 1, 1991
Creator: Parks, N. J.; Pinkerton, K. E.; Seibert, J. A. & Pool, R. R.
Partner: UNT Libraries Government Documents Department

Preliminary minimum detectable limit measurements in 208-L drums for selected actinide isotopes in mock-waste matrices

Description: Preliminary minimum detectable levels (MDLS) of selected actinide isotopes have been determined in full-scale, 55-gallon drums filled with a range of mock-waste materials from combustibles (0.14 g/CM{sup 3}) to sand (1.7 g/CM{sup 3}). Measurements were recorded from 100 to 10,000 seconds with selected actinide sources located in these drums at an edge position, on the center axis of a drum and midway between these two positions. Measurements were also made with a {sup 166}Ho source to evaluate the attenuation of these mock-matrix materials as a function of energy. By knowing where the source activity is located within a drum, our preliminary results show that a simply collimated 90% HPGE detector can differentiate between TRU (>100 nCi/g) and LLW amounts of {sup 239}Pu in only 100s of measurement time and with sufficient accuracy in both low and medium density, low Z materials. Other actinides measured so far include {sup 235}U, {sup 241}Am, and {sup 244}Cm. These measurements begin to establish the probable MDLs achievable in the nondestructive assays of real waste drums when using active and passive CT. How future measurements may differ from these preliminary measurements is also discussed.
Date: July 30, 1992
Creator: Camp, D. C.; Wang, Tzu-Fang & Martz, H. E.
Partner: UNT Libraries Government Documents Department

Reaction cross-section calculations using new experimental and theoretical level structure data for deformed nuclei

Description: A technique for modeling level structures of odd-odd nuclei has been used to construct sets of discrete states with energies in the range 0 to 1.5 MeV for several nuclei in the rare-earth and actinide regions. The accuracy of the modeling technique was determined by comparison with experimental data. Examination was made of what effect the use of these new, more complete sets of discrete states has on the calculation of level densities, total reaction cross sections, and isomer ratios. 9 refs.
Date: May 1, 1985
Creator: Hoff, R.W.; Gardner, D.G. & Gardner, M.A.
Partner: UNT Libraries Government Documents Department

Nuclear orientation studies of rare-earth metals

Description: The angular distributions of gamma rays from /sup 166m/Ho and /sup 160/Tb aligned at low temperatures in, respectively, Ho metal and Tb metal have been measured. Large hyperfine splittings, expected for the rare earths, have been deduced from the temperature dependence of the gamma-ray anisotropies. Both samples show a macroscopic magnetic anisotropy that is not consistent with an interpretation in terms of a randomly oriented polycrystalline structure.
Date: January 1, 1980
Creator: Krane, K.S.; Morgan, G.L. & Moses, J.D.
Partner: UNT Libraries Government Documents Department

Skeletal remodeling dynamics: New approaches with imaging instrumentation. [Laser confocal microscopy:a2]

Description: This report of progress and future objectives timetable is based on an included schematic of goals and objectives and the project abstract which is included as Appendix 1. Five matters are summarized in the order of (1) novel methods of calcified bone confocal microscopy and reconstruction image analysis of decalcified beagle and human cortical bone serial sections, (2) macroscopic cross-correlation of beagle and human cortical and cancellous bone fractions with CT analysis, (3) guidance to the most radiobiologically important skeletal regions of interest with the just completed {sup 90}Sr bone tumor map from life time beagle studies, (4) deposition patterns of radioactive agents that participate in apatite crystal nucleation processes in bone and leave radiation-excited electrons trapped in bone mineral, and (5) the budget period timetable. The discovery that beta particles from {sup 166}Ho (T{sub {1/2}} =26 hr, {beta}{sub max} = 1.8 MeV) phosphonic acid bone agents leave detectable, long-lived, electron paramagnetic resonance signals in bone is included in Appendix 2 as a joint report.
Date: January 1, 1991
Creator: Parks, N.J.; Pinkerton, K.E.; Seibert, J.A. & Pool, R.R.
Partner: UNT Libraries Government Documents Department

Calculations of long-lived isomer production in neutron reactions

Description: We have carried out theoretical calculations for the production of the long-lived isomers {sup 93m}Nb({1/2}{sup {minus}}, 16y), {sup 121m}Sn(11/2{minus}, 55 yr), {sup 166m}Ho(7-, 1200 yr), {sup 184m}Re(8+, 165 d), {sup 186m}Re(8+, 2{times}10{sup 5} yr), {sup 178m}Hf(16+, 31 yr), {sup 179m}Hf(25/2-, 25 d), {sup 192m}Ir(9+, 241 yr), all of which pose potential radiation activation problems in nuclear fusion reactors. We consider (n, 2n), (n,n{prime}), and (n, {gamma}) production modes and compare our results both with experimental data (where available) and systematic. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be justified theoretically but have not been experimentally resolved, were reconstructed. 16 refs., 8 figs.
Date: January 1, 1991
Creator: Chadwick, M.B. & Young, P.G.
Partner: UNT Libraries Government Documents Department

Calculations of long-lived isomer production in neutron reactions

Description: We present theoretical calculations for the production of the long-lived isomers: {sup 121m}Sn (11/2-, 55 yr), {sup 166m}Ho(7-, 1200 yr), {sup 184m}Re(8+, 165 d), {sup 186m}Re(8+, 2{times}10{sup 5} yr), {sup 178m}Hf(16+, 31 yr), {sup 179m}Hf(25/2-, 25 d), {sup 192m}Ir(9+, 241 yr), all which pose potential radiation activation problems in nuclear fusion reactors if produced in 14-MeV neutron-induced reactions. We consider mainly (n,2n) production modes, but also (n,n{sup {prime}}) and (n,{gamma}) where necessary, and compare our results both with experimental data (where available) and systematics. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be justified theoretically but have not been experimentally resolved, were reconstructed. 16 refs., 9 figs., 6 tabs.
Date: January 1, 1991
Creator: Chadwick, M.B. & Young, P.G.
Partner: UNT Libraries Government Documents Department

Low-energy structure studies of odd-odd deformed nuclei and the coriolis and residual interactions

Description: The nuclear level structure of /sup 176/Lu, /sup 170/Tm, /sup 166/Ho, and /sup 160/Tb have been studied by means of the /sup 177/Hf(t,..cap alpha..)/sup 176/Lu, /sup 171/Yb(t,..cap alpha..)/sup 170/Tm, /sup 167/Er(t,..cap alpha..)/sup 166/Ho, and /sup 161/Dy(t,..cap alpha..)/sup 160/Tb reactions and with the use of previously published (d,p) spectroscopy and gamma transitions from the (n,..gamma..) reactions. The (t,..cap alpha..) reactions have been performed and analyzed with 17 MeV tritons and the Los Alamos Q3D spectrometer. Eighty-one new rotational states in excited proton configurations or vibrational excited states are proposed. An independent parameterization of the Coriolis interaction is presented, which leads to satisfactory results in reproducing experimental single-particle transfer reaction cross-sections by theoretical calculations. The anomalous population of the excited neutron configurations (404 reduces to -624 up arrow) in /sup 176/Lu and (411 reduces to +- 512 up arrow) in /sup 170/Tm, and the anomalously low (t,..cap alpha..) cross-sections of the (411 up arrow +- 633 up arrow) configuration in /sup 166/Ho are observed. Qualitative explanation of the anomalies is presented in terms of the mixing of states which satisfy the requirement delta/sub I'/,/sub I/delta/sub K'/,/sub K/. Off-diagonal H/sub INT/ matrix elements are calculated, which show that the residual interaction cannot be used to account for the magnitude of the cross-sections observed.
Date: August 1, 1980
Creator: Dewberry, R.A.
Partner: UNT Libraries Government Documents Department