Search results for "Intensity"
showing 10 items of 1091 documents
Precision measurement of the half-life and the decay branches of 62Ga
2005
In an experiment performed at the Accelerator Laboratory of the University of Jyvaskyla, the beta-decay half-life of 62Ga has been studied with high precision using the IGISOL technique. A half-life of T1/2 = 116.09(17)ms was measured. Using beta-gamma coincidences, the gamma intensity of the 954keV transition and an upper limit of the beta-decay feeding of the 0+_2 state have been extracted. The present experimental results are compared to previous measurements and their impact on our understanding of the weak interaction is discussed.
On the decay of theJπ= 11/2−,T1/2= 38.9 h isomer in133Ba: search for the E5 transition and verification of the EC branch
2010
International audience; This paper presents a search for the competing 11/2 − → 1/2 + E5 branch to the main 11/2 − → 3/2 + M4 transition from the T 1/2 = 39 h, J π = 11/2 − isomeric state in 133 Ba. An upper limit of 1.8 * 10 −5 could be established for the E5/M4 intensity ratio. In addition a long-standing controversy in the EC-decay of the same isomer was resolved: only one EC branch to the 11/2 + state in 133 Cs was observed. The shell-model structures of the involved states in 133 Ba and 133 Cs were studied with the microscopic quasiparticle-phonon model (MQPM). Good agreement with the decay rates B(λ) was obtained. In particular, the B(M4) value is well reproduced and further only one …
Single-step link from yrast SD band in 143Eu
1997
A discrete γ-ray transition from the yrast SD band to the region of near-yrast discrete normal-deformed states has been identified in 143Eu. It has an energy of 3360.6 keV and an intensity corresponding to 3.2% of the full intensity of the SD band and feeds a nearly-spherical state above spin 352(+) and Ex=4947 keV. This agrees well with the picture of the decay out of the SD band gained previously from two-step links. The angular distribution analysis favours a stretched dipole character for the transition. Due to the complicated structure of the level scheme in the region of interest it has not been possible to place the transition exactly.
Electro-produced slow positrons
1989
During the last 6 years it has been demonstrated that electro-produced intense beams of slow positrons are possible. High energy electrons from an accelerator generate bremsstrahlung in a thick conversion target of high element number Z. The photons produce electronpositron pairs and a small fraction of the positrons may be moderated to thermal energies. A review is given of the existing slow positron beam lines using this technique. At accelerator energies of 100 MeV total conversion efficiencies of several slow positrons per 106 primary electrons have been obtained, resulting in average intensities of several 109 slow positrons per second or more than 105 slow positrons in pulses having a…
High-power production targets for the Super-FRS using a fast extraction scheme
2003
Abstract The high-power production target of the Super-FRS [H. Geissel et al., these Proceedings] will be irradiated by very intense heavy-ion beams which will be delivered from the future SIS100/200 [An International Accelerator Facility for Beams of Ions and Antiprotons, GSI-Report, 2001] synchrotron facility at the Gesellschaft fur Schwerionenforschung (GSI) Darmstadt. This paper presents calculations of the thermodynamic and the hydrodynamic response of such a target, considering that a uranium ion beam with an energy of 1 GeV/u and an intensity of 10 12 particles will impinge within 50 ns on a solid carbon target with a thickness of 4 g/cm 2 . Due to the high beam intensity the target …
High-statistics measurement of the β-delayed α spectrum of 20Na
2013
A measurement of the 20Na β-delayed alpha spectrum with a high-granularity setup has allowed the decay scheme to be revised on several points. Three new transitions of low intensity are found at low α -particle energy. An R-matrix fit of the complete spectrum gives an improved description of the decay and indicates feeding to the broad 2+ α-cluster state close to 9MeV. c Societa Italiana di Fisica / Springer-Verlag 2013
The Collinear Fast Beam laser Spectroscopy (Cfbs) experiment at Triumf
2016
Abstract Laser spectroscopy experiments at radioactive ion beam facilities around the world investigate properties of exotic nuclei for scientific endeavours such as, but not limited to, the investigation of nuclear structure. Advancements in experimental sensitivity and performance are continuously needed in order to extend the reach of nuclei that can be measured. The collinear fast beam laser spectroscopy ( Cfbs ) setup at Triumf , coupled to an out-of-plane radio-frequency quadrupole Paul trap, enables measurements of some of the most fundamental nuclear properties for long-lived ground and isomeric states. The first comprehensive overview of the Cfbs experiment is provided along with d…
High brilliance uranium beams for the GSI FAIR
2017
The 40 years old GSI-UNILAC (Universal Linear Accelerator) as well as the heavy ion synchrotron SIS18 will serve as a high current heavy ion injector for the new FAIR (Facility for Antiproton and Ion Research) synchrotron SIS100. In the context of an advanced machine investigation program in combination with the ongoing UNILAC upgrade program, a new uranium beam intensity record (11.5 emA, ${\mathrm{U}}^{29+}$) at very high beam brilliance was achieved recently in a machine experiment campaign. This is an important step paving the way to fulfill the FAIR heavy ion high intensity beam requirements. Results of high current uranium beam measurements applying a newly developed pulsed hydrogen g…
Search for forbidden?-decays of the drip line nucleus12Be
1994
Beta-coincidentγ-rays have been measured from implanted pure samples of12Be separated at the LISE3 spectrometer at GANIL. An intensity of 0.040(26) % can be estimated for the branching ratio of the isospin forbidden pure-Fermi transition to the 0+ excited state of12B and of 0.008(6)% of the transition to the 1−1 excited state. Both are taken to represent upper limits. The half-life has been re-measured to be 26.1(2.4) ms.
Strength ofJπ=1+Gamow-Teller and isovector spin monopole transitions in double-β-decay triplets
2014
In this work we study systematically the energetics and intensity distributions of Gamow-Teller (GT${}^{\ifmmode\pm\else\textpm\fi{}}$) and isovector spin monopole (IVSM${}^{\ifmmode\pm\else\textpm\fi{}}$) transitions from the ground states of the pairs ($^{76}\mathrm{Ge}$,$^{76}\mathrm{Se}$), ($^{82}\mathrm{Se}$,$^{82}\mathrm{Kr}$), ($^{100}\mathrm{Mo}$,$^{100}\mathrm{Ru}$), ($^{116}\mathrm{Cd}$,$^{116}\mathrm{Sn}$), ($^{128}\mathrm{Te}$,$^{128}\mathrm{Xe}$), ($^{130}\mathrm{Te}$,$^{130}\mathrm{Xe}$), and ($^{136}\mathrm{Xe}$,$^{136}\mathrm{Ba}$), of double-beta-decay initial and final nuclei, to the ${J}^{\ensuremath{\pi}}={1}^{+}$ excited states of the intermediate odd-odd nuclei $^{76}\…