Search results for "RADIOCHEMISTRY"

Beta decay of $^{56}$Cu

2001

AbstractThe proton-rich isotope 56 Cu was produced at the GSI On-Line Mass Separator by means ofthe 28 Si( 32 S, p3n) fusion–evaporation reaction. Its β -decay properties were studied by detecting β -delayed γ rays and protons. A half-life of 93± 3 ms was determined for 56 Cu. Compared to theprevious work, six new γ rays and three new levels were assigned to the daughter nucleus 56 Ni. Themeasured Gamow–Teller strength values for five 56 Ni levels are compared toshell-model predictions.  2001 Elsevier Science B.V. All rights reserved. PACS: 21.10.-k; 23.40.-s; 21.60.Cs; 27.40.+zKeywords: R ADIOACTIVITY 56 Cu ( β + ) [from 28 Si( 32 S, p3n)]; Measured E γ , I ; Deduced β -intensity and β -st…

A new method for the labelling of proteins with radioactive arsenic isotopes

2006

Abstract  Radioarsenic labelled radiopharmaceuticals could be a valuable asset to positron emission tomography. In particular, the long half-lives of 72As ( T 1 / 2 = 26 h ) and 74As ( T 1 / 2 = 17.8 d ) allow to investigate slow physiological or metabolical processes, like the enrichment and distribution of monoclonal antibodies (mab) in tumour tissue. In this work, a new method for the labelling of proteins with various radioactive arsenic isotopes was developed. For this purpose, two proteins, namely a chimeric IgG3 monoclonal antibody, ch3G4, directed against anionic phospholipids, and Rituxan (Rituximab), were labelled as a proof of principle with no-carrier-added radioarsenic isotopes…

The isotope shift of the radioactive Cd-isotopes (102?A?120) determined by on-line laserspectroscopy

1981

New neutron-rich isotopes of astatine and bismuth

1989

Neutron-rich isotopes of astatine have been produced through spallation reactions with 600 MeV protons on a232Th target and identified by spectroscopic techniques combined with one-line mass separation at the ISOLDE facility. The half-lives of218At and219At have been remeasured to be 1.5(3) s and 57(4) s, respectively. Four new isotopes of astatine,220−223At, have been observed for the first time, and their half-lives were found to be 3.73(13) min, 2.3(2) min, 54(10) s, and 50(7) s, respectively. Another nuclide,216Bi, has been observed for the first time as the daughter product of the220At alpha decay, and its half-life has been measured to be 6.6(21) min.

Intense beams of mass-separated, neutron-deficient indium, tin, thallium and lead isotopes

1985

A discharge ion source of the FEBIAD-type that delivers intense beams of neutron-deficient isotopes of indium, tin, thallium and lead produced in heavy-ion-induced fusion reactions is described. After mass separation the isotopically pure beams with intensities of up to 3 × 107 ions/s were available for gamma and laser spectroscopy. This corresponds to an overall separation efficiency of about 30%.

Determination of the content in uranium oxide particles by fission track analysis

2004

Abstract One of the most important tasks of nuclear safeguards is to control the activities in nuclear facilities worldwide. These activities include the enrichment of 235 U . To identify enrichments above the maximum authorised level in commercial enrichment plants (usually 5% 235 U ) swipe tests are performed and the 235 U enrichment is determined in the sampled uranium oxide particles. A method is described that allows to measure the 235 U content in small particles (around 1 μm in diameter) by the use of fission tracks. It is based on the fact that in uranium fuel, only 235 U atoms are fissile with thermal neutrons and contribute to the amount of fission tracks counted for individual pa…

Production and characterization of a custom-made 228Th source with reduced neutron source strength for the Borexino experiment

2012

A custom-made 228Th source of several MBq activity was produced for the Borexino experiment for studying the external background of the detector. The aim was to reduce the unwanted neutron emission produced via (alpha,n) reactions in ceramics used typically for commercial 228Th sources. For this purpose a ThCl4 solution was converted chemically into ThO2 and embedded into a gold foil. The paper describes the production and the characterization of the custom-made source by means of gamma-activity, dose rate and neutron source strength measurements. From gamma-spectroscopic measurements it was deduced that the activity transfer from the initial solution to the final source was >91% (at 68%…

Bemerkung zur Mehrfach-Emission von Sekund�relektronen

1964

Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE

2017

At ISOLDE the majority of radioactive ion beams are produced using the resonance ionization laser ion source (RILIS). This ion source is based on resonant excitation of atomic transitions by wavelength tunable laser radiation. Since its installation at the ISOLDE facility in 1994, the RILIS laser setup has been developed into a versatile remotely operated laser system comprising state-of–the-art solid state and dye lasers capable of generating multiple high quality laser beams at any wavelength in the range of 210–950 nm. A continuous programme of atomic ionization scheme development at CERN and at other laboratories has gradually increased the number of RILIS-ionized elements. At present, …

The new neutron-rich nuclei231Fr and231Ra

1985

The new neutron-rich isotope231Fr has been produced in a spallation reaction of238U induced by 600 MeV protons and identified by mass-separation and decay spectroscopy. In addition, the so far unknown231Ra and the known231Ac have been observed as daughter products. The Z-assignments were performed via the decay of KX-rays, and genetic relationships. Half-lives of 17.5(8) s and 103(3) s were obtained for231Fr and231Ra, respectively.