47 Matching Results

Search Results

Advanced search parameters have been applied.

In Vitro Assessment of the In Vivo Stability of Cu-64 Radiopharmaceuticals

Description: Research Plans: The successful development of Cu-64 radiopharmaceuticals depends upon retention of the Cu-64 atom in the radiopharmaceutical. To date, the focus has been on the development of chelators that better retain Cu-64, but there has been no effort to develop an effective method by which improved retention may be measured. In the absence of a suitable analytical method, the stability of Cu-64 radiopharmaceuticals is estimated indirectly, with decreased liver uptake suggesting higher in vivo complex stability. But this approach is inadequate for radiopharmaceuticals, such as radiolabeled antibodies, that are expected to accumulate in the liver even when there is no free Cu-64 present. The absence of such a method has also hampered efforts to systematically evaluate the chemical factors that may give rise to improved retention. The objective of this project is to develop and validate such a method. Accomplishments: The two primary accomplishments of this project will be 1) the development and validation of a method to measure the stability of Cu-64 radiopharmaceuticals and 2) the determination of the chemical factors that define the in vivo stability of Cu 64 radiopharmaceuticals. Because Cu(II) is extremely labile, the in vivo stability of Cu-64 radiopharmaceuticals is not primarily determined by the amount of “free” Cu that is present at any given time or by the thermodynamic stability constants, but rather by the rate at which Cu is lost from the complex, the dissociation rate constant, kd. The dissociation rate constants of the Cu-64 complexes from a series of bifunctional chelators (BFCs) will be measured using Free Ion Selective Radiotracer Extraction (FISRE), a technique originally developed to measure bioavailable Cu in environmental samples. FISRE will also be applied to the determination of the kd’s of a series of reference Cu-64 complexes to determine the chemical factors that define the in vivo ...
Date: December 15, 2011
Creator: Packard, Alan B.
Partner: UNT Libraries Government Documents Department

Biomedical Radioisotope Program. Progress report for quarter ending March 31, 1977

Description: Progress is reported for the applications of {sup 11}C, {sup 195m}Pt, and {sup 123m}Te. Of note in this report period is the presentation of images of rat adrenals with a {sup 123m}Te-labeled steriod and an investigation of steriod structural parameters which affect adrenal concentration. Two new {sup 195m}Pt-labeled compounds have been prepared for evaluation as chemotherapeutic agents.
Date: June 1, 1977
Creator: Poggenburg, J.K.
Partner: UNT Libraries Government Documents Department

Oncogene mRNA Imaging with Radionuclide-PNA-Peptides

Description: New cancer gene hybridization probes to carry radionuclides were made. Noninvasive technetium-99m gamma imaging of CCND1 cancer gene activity in human breast cancer tumors in mice was demonstrated, followed by noninvasive technetium-99m imaging of MYC cancer gene activity. Noninvasive imaging of CCND1 cancer gene activity in human breast cancer tumors in mice was demonstrated with a positron-emitting copper-64 probe, followed by noninvasive positron imaging of IRS1 cancer gene activity.
Date: March 19, 2008
Creator: Wickstrom, Eric
Partner: UNT Libraries Government Documents Department

A high intensity slow positron facility for the Advanced Neutron Source

Description: A slow positron spectroscopy facility, based on {sup 64}Cu activation, has been designed for incorporation in the Advanced Neutron Source (ANS). The ANS is a reactor-based research center planned for construction at Oak Ridge, Tennessee, USA. Multiple sources of slow positron beams will be available. One-half mm diameter, copper-coated aluminum microspheres will be activated and transported to a positron spectroscopy building, where they will be dispersed over the surfaces of horizontal pans, 0.1 m{sup 2} in area, located in source chambers. Fast positions from the pans will be intercepted by cylinders coated inside with inert gas moderators. Yields will approach 10{sup 12} positrons per second before brightness enhancement. Beams will be transported to multiple experiment stations, which will include a 50 meter diameter, 20-detector angular correlation of annihilation radiation (ACAR) spectrometer, and other equipment for materials analysis and fundamental science.
Date: July 1, 1994
Creator: Hulett, L. D. Jr. & Eberle, C. C.
Partner: UNT Libraries Government Documents Department

Solid neon moderated electrostatic or magnetic positron beam

Description: A high intensity variable energy positron beam has been constructed at Brookhaven National Laboratory (BNL). Positrons from a 97mCi {sup 22}Na source are moderated by a thin layer of solid neon. A magnetic guiding system delivered up to 5{times}10{sup 6}e{sup +}/sec to an experiment. Currently tests are under way to facilitate the operation with the magnetic guiding system or -- for other experimental sites -- with an electrostatic beam transport. The electrostatic lenses are fabricated from {mu}-metal. No compensation of the earth magnetic field is required. Several experiments can utilize the beam on a time sharing basis. In the near future the source will be replaced by {sup 64}Cu which has a much higher activity. Beam intensities up to 10{sup 9}e{sup +}/sec are expected.
Date: December 31, 1991
Creator: Weber, M.; Schwab, A.; Becker, D. & Lynn, K. G.
Partner: UNT Libraries Government Documents Department

Moisture measurement for high-level-waste tanks using copper activation probe in cone penetrometer

Description: Laboratory tests have established the feasibility of using neutron activation of copper as a means for measuring the moisture in Hanford`s high-level radioactive waste tanks. The performance of the neutron activation technique to measure moisture is equivalent to the neutron moisture gauges or neutron logs commonly used in commercial well-logging. The principle difference is that the activation of {sup 64}Cu (t{sub 1/2} = 12.7 h) replaces the neutron counters used in moisture gauges or neutron logs. For application to highly radioactive waste tanks, the Cu activation technique has the advantage that it is insensitive to very strong gamma radiation fields or high temperatures. In addition, this technique can be deployed through tortuous paths or in confined spaces such as within the bore of a cone penetrometer. However, the results are not available in ``real-time``. The copper probe`s sensitivity to moisture was measured using simulated tank waste of known moisture content. This report describes the preparation of the simulated waste mixtures and the experiments performed to demonstrate the capabilities of the neutron activation technique. These experiments included determination of the calibration curve of count rate versus moisture content using a single copper probe, measurement of the calibration curve based on ``near-field `` to ``far-field`` counting ratios using a multiple probe technique, and profiling the activity of the copper probe as a function of the vertical height within a simulated waste barrel.
Date: October 1, 1995
Creator: Reeder, P.L.; Stromswold, D.C.; Brodzinski, R.L.; Reeves, J.H. & Wilson, W.E.
Partner: UNT Libraries Government Documents Department

POSITRON SCANNER FOR BRAIN TUMORS

Description: It was thought that if a multi-detector device could be developed, the scanning time would be greatly shortened, with such consequent advantages as being able to work with lower dose of radiation, to obtain serial determinations, and to work with shorter-lived isotopes.
Date: October 9, 1964
Creator: Robertson, J.S. & Bozzo, S.R.
Partner: UNT Libraries Government Documents Department

Residual Radiation of the LRL 184-Inch Cyclotron

Description: Residual radioactivity at the Lawrence Radiation Laboratory 184-Inch Cyclotron was measured during November 1960. The study was conducted along three principal lines: (1) general survey of radiation levels in the cyclotron vault, (2) activation of foils placed near the cyclotron, and (3) gamma-ray spectra of the cyclotron gap region, including dee structure. Initial radiation levels were less than 8 r/hr which dropped to abcut 10 mr/hr after 48 hr. The observed activities induced in copper foils were Cu/sup 64/ and Co/sup 58/; in iron foils, Mn/sup 52/, Mn/sup 54/, and Mn/sup 56/; in aluminum foils Na/sup / 2>s/sup 4/ The gamma-ray spectra from the gap region included two intense long-lived peaks, at 510 and 810 kev, caused principally by Co/sup 58/. (auth)
Date: July 12, 1961
Creator: Boom, R. W.; Toth, K. S. & Zucker, A.
Partner: UNT Libraries Government Documents Department

ELECTRON-SLOWING-DOWN SPECTRUM IN Cu OF BETA RAYS FROM Cu$sup 6$$sup 4$

Description: The electron flux spectrum resulting from the slowing down of electrons from /sup 64/Cu uniformly distributed in Cu was measured from 0.1 ev to 37 kev for both a plane disk source and a black body cavity source. The cavity source consisted of a hollow Cu frustrum with walls infinitely thick for /sup 64/Cu beta rays. A matching thick cover allowed only electrons from inside the cavity to enter the Keplertron, a spherical electrostatic beta spectrometer. The cavity data agreed well from 1 kev to 37 kev with a simplified calculation of the Spencer-Fano theory. Below 1 kev, the experimental flux exceeded the calculated flux by as much as 35% at 30 ev. A stopping power derived from proton dath was used in the theory for electrons below 5.5 kev. A buildup of several orders of magnitude in the electron flux below 1 kev was observed. The disk data was lower than the cavity data at all energies above 1 kev, the former approaching the latter at higher energies. The beth spectrometer was calibrated for transmission and resolution from 1.5 ev to 3 kev using an isotropic electron gun and at 31.4 kev using the /sup 152/Sm Auger line. (auth)
Date: May 1, 1964
Creator: McConnell, W.J.; Hubbell, H.H. Jr. & Birkhoff, R.D.
Partner: UNT Libraries Government Documents Department

The fitting of radioactive decay data by covariance methods

Description: The fitting of radioactive decay data is examined when radiations from two or more processes are indistinguishable. The model is a nonlinear sum of exponentials which cannot be linearized by transformations. Simple and generalized least-squares procedures utilizing covariance matrices are applied. The validity of the midpoint approximation is demonstrated. Guidelines for acquiring adequate radioactive decay data are suggested. The relevance to activation cross section determination is discussed.
Date: April 1, 1994
Creator: Smith, D. L. & Osadebe, F. A. N.
Partner: UNT Libraries Government Documents Department

Nuclear Reactions Induced by Pions and Protons

Description: Effects due to elementary particle-like collisions within nuclear matter have been observed in several nuclear reactions caused by pions and protons. Simple nuclear reactions of the form ZA(a,an)Z/sup A-1/ and Z/sup A/(a,ap)(Z-1)/ sup A-1/ have excitation functions that are sensitive to changes in the elementary-particle cross sections. The excitation function for the reaction C/ sup 12/( pi /sup -/, pi /sup -/n)C/sup 11/ is measure d from 53 to 1610 Mev by bombarding targets of plastic scintillator with pions. The intensity of the pion beam is monitored with a two-counter telescope and 40 Mc scaling system. The scintillator target is mounted on a phototube and becomes the detector for the carbon-11 positron activity. Corrections are made for muon contamination in the beam, coincidence losses in the monitor system, carbon-11 activity produced by stray background at the accelerator, carbon-1l activity produced by secondaries in the target, and the efficiency of the carbon-11 detection system. The C/sup 12/( pi /sup -/, pi /sup -/n)C/sup 11/ cross sections rise to a peak of abo ut 70 mb at 190 Mev, that corresponds to the resonance in freeparticle pi /sup -/n scattering at 190 Mev. Calculations based on a knock-on'' collision mechanism and sharp-cutoff nuclear density reproduce the shape of the experimental excitation function, but the magnitudes of the calculated values are low by a factor of six, The calculation shows that the C/sup 12/( pi /sup -/, pi /sup -/ n)C/sup 11/ reaction occurs in the nuclear s urface region at all bombarding energies, The contributions to the ( pi /sup -/, pi /sup -/n) reaction predominate on the front surface of the nucleus in order to give the pion the maximum probability of escaping. The excitation functions for the reactions ured radiochemically from 400 Mev to 6.2 Bev. The slight increase in ...
Date: November 27, 1962
Creator: Reeder, P. L.
Partner: UNT Libraries Government Documents Department

Measurement of Spectral Distribution of Positron Flux in an Infinite Copper Medium Containing Cu$sup 64$

Description: The spectral distribution of the flux of positrons inside a beta radioactive medium was experimentally determined using an anthracene coincidence scintillation spectrometer. Positrons leaving a copper cavity source containing Cu/sup 64/ were absorbed in a thin anthracene crystal. The light pulse from the anthracene was recorded in a 256 channel analyzer if a NaI scintillation spectrometer nearby recorded simultaneously a count under the total absorption peak for annihilation radiation. Thus, discrimination against negative and secondary electrons was obtained which permitted observation of the primary positron slowing down flux. Data were corrected for the non-linear pulse height vs energy relationship in anthracene by a semi-empirical theory due to Birks, the validity of which was demonstrated by its use in obtaining a linear Fermi plot of Pm/sup 147/. Positron spectra were corrected also for Compton absorption of the annihilation radiation in the anthracene. Results were compared with the theoretical continuous-slowing-down model. Over the energy range measured (20-- 650 kev) it was concluded that the continuous-slowing-down model gives the correct shape for the primary slowing-down spectrum. 43 references. (auth)
Date: December 24, 1963
Creator: Wilkie, W. H. & Birkhoff, R. D.
Partner: UNT Libraries Government Documents Department

Use of total beta counts to estimate GI tract dose rates

Description: It was the practice for several years to estimate the potential dose rate to the gastrointestinal from sanitary water sources by evaluating the results of radiochemical analysis of individual nuclides. The proposed method estimates the GI tract dose from Pasco and Richland domestic water from measurements of the total beta activity, and permits more frequent and more economical evaluation of a variable source of radiation exposure. Beginning with 1964 data, the GI tract dose rate for Richland and Pasco sanitary water has been obtained by multiplying the total beta count by a conversion factor derived from the historical relationship between the radiochemical analyses and the total beta counts. Either the accumulation of more data or changes in the relative abundance of the more significant nuclides in the water may result in changes in this factor.
Date: October 25, 1965
Creator: Hall, R. B.
Partner: UNT Libraries Government Documents Department

An anion exchange-precipitation procedure for the determination of Na{sup 24} in reactor effluent water

Description: The isotope Na{sup 24} is one of the major short half-life constituents of reactor effluent water. It has a half-life of 15 hours and decays of emission of a 1.39 MeV maximum beta particle. Other radioisotopes present in reactor effluent water from which Na{sup 24} must be separated are Si{sup 31}, P{sup 32}, Mn{sup 56}, Cu{sup 64}, As{sup 76}, Sr{sup 91--92}, Ba{sup 139--140} and rare earths. This report describes a rapid and very simple method for the quantitative determination of Na{sup 24} in a radiochemically pure form.
Date: August 10, 1955
Creator: Perkins, R. W.
Partner: UNT Libraries Government Documents Department

Summary of the Savannah River Site Criticality Dosimetry Program

Description: The mission of the Savannah River Site (SRS) includes working with fissionable materials. A program is in place, therefore, to assess neutron and gamma doses to individuals in the event of a criticality accident at SRS. The program consists of a method to quickly screen for potentially exposed personnel, a method to provide early but preliminary dose estimates, and a nuclear accident dosimeter and assay procedure to enable final dose estimates.
Date: February 1, 1993
Creator: Crase, K. W.
Partner: UNT Libraries Government Documents Department

Study of high energy nucleus nucleus collisions

Description: The CERN experiment WA80 studies ultrarelativistic heavy ion collisions by calorimetry and charged particle measurements over a large fraction of 4..pi... Here I want to concentrate on a closer study of nucleus nucleus collisions and recent results from the lead glass spectrometer Saphir. 6 refs., 5 figs.
Date: August 1, 1988
Creator: Franz, A.
Partner: UNT Libraries Government Documents Department

Preparation of radiopharmaceuticals labeled with metal radionuclides. Progress report, July 1, 1988--June 30, 1992

Description: We recently developed a useful zinc-62/copper-62 generator and are presently evaluating copper-62 radiopharmaceuticals for clinical studies. While developing these copper-62 radiopharmaceuticals, in collaboration with the University of Missouri Research Reactor, Columbia we have also explored copper-64 radiopharmaceuticals. The PET images we obtained with copper-64 tracers were of such high quality that we have developed and evaluated copper-64 labeled antibodies for PET imaging. The major research activities described herein include: the development and assessment of gallium-68 radiopharmaceuticals; the development and evaluation of a new zinc-62/copper-62 generator and the assessment of copper-62 radiopharmaceuticals; mechanistic studies on proteins labeled with metal radionuclides.
Date: June 1, 1992
Creator: Welch, M. J.
Partner: UNT Libraries Government Documents Department

PHYSICS DIVISION SUMMARY REPORT

Description: Half lives were determined for 10 transitions in low-lying energy levels, excited by slow neutron capture, in Mn/sup 5//sup 6/, Rh/sup 1//sup 0// sup 4/, Cu/sup 6//sup 4/, Al/sup 2//sup 8/, and I/sup 1//sup 2//sup 8/. Internal ma gnetic fields at the nuclei of Fe/sup 5//sup 7/ and Sn/sup 1//sup 1//sup 9/ in various magnetic media were studied with the Mossbauer effect, and their nuclear Zeeman effects were snalyzed. Energy spectra, angular distributions, and reduced widths were obtained for (d,t) reactions on Fe/sup 5//sup 4/, Fe/sup 5//sup 8/, Ni/sup 5//sup 8/, Ni/sup 6//sup 0/, and Ni/sup 6/>s1< s, and the data used to provide information on the ground-state wave functions of these isotopes. The beta and gamma radiations associated with Er/sup 1//sup 7//sup 2/ decay were measured and a decay scheme proposed for Er/sup 1//sup 7//sup 2/. The level structure of F/sup 2//sup 0/ at 1 to 150 kev above the neutron binding energy was studied by the F/sup 1//sup 9/(n,n)F/sup 1//sup 9/ ess. The region around 100 kev was found to contain a cluster of levels. A polystyrene film was prepared with a thickness of 530 A and its vacuum ultraviolet spectrum determined in the range 1100 to 2300 A. Experimental data on the kinetic energies of fragments from electron bombardment of ethylene and acetylene are interpreted in terms of a "temperature." The form factors for the inelastic scattering of high-energy electrons are calculated for Sm/sup 1//sup 5//sup 2/ with the collective model of a deformed nucleus. A singleparticle rotational model, which includes band mixing, was found to give a qualitative fit to many of the properties of the low- lying states in Fe/sup 5//sup 7/ with the exception of those depending on the intrinsic wave function of the 1/2/sup -/ ground state. (D.L.C.)
Date: March 1, 1961
Partner: UNT Libraries Government Documents Department

Electromagnetic dissociation of relativistic {sup 28}Si by nucleon emission

Description: A detailed study of the electromagnetic dissociation of {sup 28}Si by nucleon emission at E{sub lab}/A = 14.6 (GeV/nucleon was carried out with {sup 28}Si beams interacting on {sup 208}Pb). {sup 120}Sn. {sup 64}C targets. The measurements apparatus consists of detectors in the target area which measure the energy and charged multiplicity, and a forward spectrometer which measures the position, momentum and energy of the reaction fragments. The exclusive electromagnetic dissociation cross sections for decay channels having multiple nucleons in the final state have been measured which enables the selection of events produced in pure electromagnetic interactions. The measured cross sections agree well with previous measurements obtained for the removal of a few nucleons as well as with measurements on total charge removal cross sections from other experiments. The dependence of the integrated cross sections on the target charge Z{sub T} and the target mass AT confirms that for higher Z targets the excitation is largely electromagnetic. Direct measurements of the excitation energy for the electromagnetic dissociation of {sup 28}Si {yields} p+{sup 27}Al and {sup 28}Si {yields} n+{sup 27}Si have been obtained through a calculation of the invariant mass in kinematically, reconstructed events. The excitation energy spectrum for all targets peak near the isovector giant dipole resonance in {sup 28}Si. These distributions are well reproduced by combining the photon spectrum calculated using the Weizsaecker-Williams approximation with the experimental data on the photonuclear {sup 28}Si({sub {gamma},p}){sup 27}Al and {sup 28}Si({sub {gamma},n}){sup 27}Si. The possibilities of observing double giant dipole resonance excitations in {sup 28}Si have been investigated with cross section measurements as well as with excitation energy reconstruction.
Date: December 1, 1992
Creator: Sonnadara, Upal Jayasiri
Partner: UNT Libraries Government Documents Department

Phase 1 summaries of radionuclide concentration data for vegetation, river water, drinking water, and fish. Hanford Environmental Dose Reconstruction Project

Description: The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at the Hanford Site since 1944. As part of the HEDR Project, the Environmental Monitoring Data Task (Task 05) staff assemble, evaluate, and summarize key historical measurements of radionuclide concentrations in the environment as a result of Hanford operations. The scope of work performed during Phase I included initiating the search, recovery, and inventory of environmental reports. Summaries of the environmental monitoring data that were recovered and evaluated are presented for specific periods of interest. These periods include vegetation monitoring data (primarily sagebrush) for the years 1945 through 1947, Columbia River water and drinking water monitoring data for the years 1963 through 1966, and fish monitoring data for the years 1964 through 1966. Concern was limited to those radionuclides identified as the most likely major contributors to the dose potentially received by the public during the times of interest: phosphorous-32, copper-64, zinc-65, arsenic-76, and neptunium-239 in Columbia River fish and drinking water taken from the river, and iodine-131 in vegetation. This report documents the achievement of the Phase I objectives of the Environmental Monitoring Data Task.
Date: June 1, 1993
Creator: Denham, D. H.; Dirkes, R. L.; Hanf, R. W.; Poston, T. M.; Thiede, M. E. & Woodruff, R. K.
Partner: UNT Libraries Government Documents Department

Subthreshold pion production

Description: This process is relatively well-understood, and one of the aims of subthresold production experiments is to identify other collective effects. Some possible signatures of collective effects are: Production below the 'absolute' threshold; production in excess predictions of nucleon-nucleon models; and a change in the characteristic behavior of the pion spectra as the threshold is crossed. This paper discusses these collective effects especially the last one. (LSP)
Date: November 1, 1987
Creator: Miller, J.
Partner: UNT Libraries Government Documents Department