Unstable Nuclides Research Articles

The proposed Penning trap mass spectrometer facility at TASCC

The proposed Penning trap mass spectrometer, to be located at the TASCC facility of the Chalk River Laboratories, is described. The facility will be used for precise atomic mass determinations among both stable and unstable nuclides. The unstable nuclides would be produced in heavy ion reactions using the TASCC facility. The products from these reactions would be collected using an He-jet transport system loaded with NaCl aerosols. After transport to a background free area, the nuclides of interest would be laser desorbed and resonantly ionized. Subsequently, these ions would be accumulated in a Paul trap, cooled and injected into a precision Penning trap mass spectrometer for mass analysis.

Estimate of (n, p) Cross Section for Unstable Nuclide 60Co by Multi-Step Hauser-Feshbach Model with Pre-Equilibrium Correction.

Abstract The cross section of the (n, p) reaction for unstable target nuclide 60Co was estimated by a multi-step Hauser-Feshbach model code with pre-equilibrium correction. Parameters used in the model calculations were determined from the fitting of the cross sections to existing experimental data of (n, p), (n, α) and (n, 2n) cross sections and particle emission spectra for the adjacent stable nuclide 59Co. The present result for 60Co(n, p)60Fe was compared with the values estimated from semi-empirical formulae around 14 MeV, The prediction accuracy of the present calculation is considered to satisfy the requirement for the fusion reactor applications. The theoretical model calculations with a reliable parameter set are recommended rather than the semi-empirical formulae for the important activation cross sections of exotic target nuclei including unstable ones.

Instrumental background in balloon-borne gamma-ray spectrometers and techniques for its reduction

A study of the instrumental background in balloon-borne gamma-ray spectrometers is presented. The calculations are based on newly available interaction cross sections and new analytic techniques, and are the most detailed and accurate published to date. Results compare well with measurements made in the 20 keV to 10 MeV energy range by the Goddard Low Energy Gamma-ray Spectrometer (LEGS). The principal components of the continuum background in spectrometers with Ge detectors and thick active shields are (1) elastic neutron scattering of atmospheric neutrons on the Ge nuclei, (2) aperture flux of atmospheric and cosmic gamma rays, (3) β − decays of unstable nuclides produced by nuclear interactions of atmospheric protons and neutrons with Ge nuclei, and (4) shield leakage of atmospheric gamma rays. The improved understanding of these components leads to several recommended techniques for reducing the background. These include minimizing the passive material inside the shield and reducing the level of the shield threshold. A new type of coaxial n-type Ge detector with its outer contact segmented into horizontal rings can be used in various modes to reduce background in the 20 keV to 1 MeV energy range. The resulting improvement in instrument sensitivity to spectral lines is a factor of ∼ 2 in this energy range.

Nuclear moments and charge radii of rare-earth isotopes studied by collinear fast-beam laser spectroscopy

The collinear fast-beam laser technique is being used to measure systematically hyperfine structures and isotope shifts of unstable nuclides in the rare-earth region. This brief report gives a general survey of the results obtained for the even-Z elements64Gd,66Dy,68Er and70Yb, with emphasis on the nuclear spins and moments. They allow a rather complete mapping of the single-particle structure and the development of nuclear deformation in the N > 82 region. The spins, magnetic moments and spectroscopic quadrupole moments of159–169Yb are presented in detail.

Operation of a long helium jet transport system with solid, monodisperse aerosols

Solid, monodisperse aerosols of NaCl, KCl, and AgCl have been used in a helium jet capillary system to transport unstable nuclides of Cu, Zn, Ga, and Sb a distance of 110 m. Overall transport efficiencies of ~ 60% have been achieved.

Cyclotron production of unstable nuclides for medical applications

Cyclotron production of unstable nuclides for medical applications

Nuclear Radii and Magnetic Moments ofBa128,131from High-Resolution Laser Spectroscopy

Mass-separated samples of the unstable nuclides $^{128}\mathrm{Ba}$ (${T}_{\frac{1}{2}}=2.4$ d) and $^{131}\mathrm{Ba}$ (${T}_{\frac{1}{2}}=11.5$ d) have been investigated by means of Doppler-free laser spectroscopy, using cw dye lasers and a well-collimated atomic beam. From isotope shifts and hyperfine structure of the $^{1}S_{0}\ensuremath{-}^{1}P_{1}$ transition ($\ensuremath{\lambda}=553.6$ nm) we obtained the differences of mean-square charge radii $\ensuremath{\delta}〈{r}^{2}〉(^{131}\mathrm{Ba}\ensuremath{-}^{130}\mathrm{Ba})=\ensuremath{-}0.006(3)$ ${\mathrm{fm}}^{2}$ and $\ensuremath{\delta}〈{r}^{2}〉(^{130}\mathrm{Ba}\ensuremath{-}^{128}\mathrm{Ba})=\ensuremath{-}0.022(3)$ ${\mathrm{fm}}^{2}$ and the magnetic moment of $^{131}\mathrm{Ba}$, $\ensuremath{\mu}=\ensuremath{-}0.714(6){\ensuremath{\mu}}_{N}$.

Die Bestimmung von53Mn, Welches in Meteoritischem Material Durch Kosmische Strahlung Erzeugt Wurde, mit Hilfe der Neutronenaktivierung

Among a number of stable and unstable nuclides formed in material exposed to cosmic radiation the spallation nuclide53Mn (T=2·106a) is investigated in meteoritic manganese by combined techniques of neutron activation and advanced γ-spectrometry. The need for an economic use of precious meteorites is so ensured best. Intense neutron bombardment transforms the long-livedK-emitter53Mn into54Mn, which is detected by its 0.84 MeV γ-rays. Using the (n,γ) cross section—recently derived byMillard—53Mn-values in the range of 60–600 dpm/kg (10−11 g/g) are found in a larger number of iron meteorite samples, which are only 1–3 g in weight. The determination is very specific and under appropriate conditions unaffected by side reactions. The attempt to use the44Ti (n,γ)45Ti reactions for the analysis of spallogenic titanium failed, because the σtherm of44Ti was found to be unexpectedly low (10 barns). Additionally,45Sc was determined after (n,γ) reaction by the46Sc γ,γ-cascades.

THE VALUE OF HG-203 BRAIN SCANS IN PATIENTS WITH INTRACRANIAL HEMATOMAS.

Brain scanning with radioactive isotopes has become sufficiently reliable to be employed in many medical centers in the detection and localization of intracranial mass lesions. Most reports indicate that certain intracranial neoplasms, i.e., meningiomas, malignant gliomas, and metastatic tumors, can usually be detected by the scan. The mechanisms of the selective localization of tracer substance in or around intracranial neoplasms are not yet fully known, nor is there evidence that a single etiological condition is operative in all instances. Among the factors that appear to be related to the increased uptake of various unstable nuclides in the brain are : (a) selective breakdown of the blood-brain and/or blood-tumor barrier, (b) increased vascularity of neoplastic tissue, (c) increased mitotic activity of neoplastic tissue, and (d) selective acquisition of a specific colloid or crystalloid by a particular tumor. If the selective accumulation of an isotope in the region of a brain tumor is not related exc...

External Collimation Detection of Intracranial Neoplasia with Unstable Nuclides

Back to table of contents Previous article Next article ArticleNo AccessExternal Collimation Detection of Intracranial Neoplasia with Unstable NuclidesW. J. FRIEDLANDERW. J. FRIEDLANDERSearch for more papers by this authorPublished Online:1 Apr 2006https://doi.org/10.1176/ajp.116.1.93AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail "External Collimation Detection of Intracranial Neoplasia with Unstable Nuclides." American Journal of Psychiatry, 116(1), p. 93 Access content To read the fulltext, please use one of the options below to sign in or purchase access. Personal login Institutional Login Sign in via OpenAthens Purchase Save for later Item saved, go to cart PPV Articles - American Journal of Psychiatry $35.00 Add to cart PPV Articles - American Journal of Psychiatry Checkout Please login/register if you wish to pair your device and check access availability. Not a subscriber? Subscribe Now / Learn More PsychiatryOnline subscription options offer access to the DSM-5 library, books, journals, CME, and patient resources. This all-in-one virtual library provides psychiatrists and mental health professionals with key resources for diagnosis, treatment, research, and professional development. Need more help? PsychiatryOnline Customer Service may be reached by emailing [email protected] or by calling 800-368-5777 (in the U.S.) or 703-907-7322 (outside the U.S.). FiguresReferencesCited byDetailsCited ByNone Volume 116Issue 1 July 1959Pages 93-93 Metrics PDF download History Published online 1 April 2006 Published in print 1 July 1959

ReviewExternal Collimation Detection of Intracranial Neoplasia with Unstable Nuclides. By ShyG. M., BradleyR. B. and MatthewsW. B., pp. vii+144, 1958 (Edinburgh and London, E. and S. Livingstone), 30s.

ReviewExternal Collimation Detection of Intracranial Neoplasia with Unstable Nuclides. By ShyG. M., BradleyR. B. and MatthewsW. B., pp. vii+144, 1958 (Edinburgh and London, E. and S. Livingstone), 30<i>s</i>.

NOTICES OF RECENT PUBLICATIONS

Journal Article NOTICES OF RECENT PUBLICATIONS Get access External Collimation Detection of Intracranial Neoplasia with Unstable Nuclides. By G. M. SHY, R. B. BRADLEY and W. B. MATTHEWS. 1958. Pp. 144. Edinburgh and London: E. & S. Livingstone Ltd. Price £1 10s. Od. N. G. TROTT N. G. TROTT Search for other works by this author on: Oxford Academic PubMed Google Scholar Brain, Volume 82, Issue 2, June 1959, Pages 294–295, https://doi.org/10.1093/brain/82.2.294 Published: 01 June 1959

External Collimation Detection of Intracranial Neoplasia with Unstable Nuclides

External Collimation Detection of Intracranial Neoplasia with Unstable Nuclides

Book Review: External Collimation Detection of Intracranial Neoplasia with Unstable Nuclides

Book Review: External Collimation Detection of Intracranial Neoplasia with Unstable Nuclides

SEARCH FOR SUCCESSIVE NEUTRON CAPTURE REACTIONS ON Mg26, Si30, AND Cr54

Stable nuclides exposed to intense neutron fluxes may produce second order reactions by successive capture of two neutrons. This method has been applied in the present work in an attempt to determine the pile neutron capture cross section of three unstable nuclides, namely: Mg27, Si31, and Cr55. A maximum value of 0.04 barn has been obtained for the cross section of Mg27. Assuming that Si32 and Cr56 are long-lived, minimal ratios of 600 and 270 years/barn respectively were obtained for [Formula: see text]