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Laser spectroscopy study on the neutron-rich and neutron-deficient Te isotopes. Laboratoire Aimé Cotton, Orsay, France Physics Department, McGill University, Montréal, Canada Laboratoire de Physique Subatomique et de Cosmologie, Grenoble, France
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Laser spectroscopy study on the neutron-rich and neutron-deficient Te isotopes Laboratoire Aimé Cotton, Orsay, France Physics Department, McGill University, Montréal, Canada Laboratoire de Physique Subatomique et de Cosmologie, Grenoble, France Institut für Physics der Universität Mainz, Mainz, Germany Institut de Physique Nucléaire, Orsay, France Centre de Spectrométrie de Nucléaire et de Spectrométrie de Masse, Orsay, France • Physics motivations • Experimental setup • Tests on stable beams : • - production • - efficiency and IS measurements • Beam time request
Laser spectroscopy d<r2> from IS m, Qs from the hyperfine structure the isotope shift could be determined in 17 cases the sign of m could be determined in 7 cases the m value with its sign in 7 cases more the Qs value with its sign in 13 cases the isomeric shift could be measured in 7cases
Laser spectroscopy d<r2> from IS m, Qs from the hyperfine structure Neutron-rich Te isotopes near N=82 : to study the variation of the kink at N=82 Te ? ? Neutron-deficient isotopes, N<82 : to search for dynamic effects
COMPLIS resonant ionization spectroscopy on laser-desorbed atoms • COMPLIS • frequency scanning • mass selection by TOF • delay between collection and desorption, • to discriminate between m and g when T1/2 • are different : 133,131,129Te • SIINODE • frequency set to a resonant transition • ions collected on the tape and transported in • front of a g-detector • to discriminate between m and g, when T1/2 • similar or both long, but g-rays observed in • the m and g decay different : 121,119,115Te
Kr inlet Ta cathode NiTe alloy Insulators made of boron nitride Ion source designed and built to produce stable beams of tellurium
Tests performed with the tellurium stable beams • graphite 5890 type desorption power 2 mJ • pyrolytic desorption power 1mJ • ionization schemes No auto-ionizing level has been found Efficiency measured on sources with 1013 atoms of 128Te : 5×109 too low !!
Tests performed with the tellurium stable beams provided by the frequency tripling of a Nd-YAG laser a to increase the ionization efficiency a overall efficiency measured on 1013, 1012 and 1011stable Te collections : e = 5×107g gain ~ 100 OK ! • Frequency scan using spread source (2×1011 atoms of 126,128,130Te on 2 cm graphite width) : • step of 30 MHz in UV • 5×108 Te atoms available for each a frequency step • equivalent to an on-line experiment • evidence of our ability to perform measurements on radioactive isotopes
Beam time request ISOLDE a Te isotope study from the neutron mid-shell to the nuclei located beyond the neutron shell closure at N = 82 • Neutron-rich isotopes • UCx + hot plasma ion source Cs to be reduced • Te produced directly • A = 129 up to 136 • odd-A : g.s. and isomeric state • with different T1/2 • a 17 shifts Neutron-deficient isotopes aCe2O + hot plasma ion source Te produced directly A = 121 down to 112 odd-A : T1/2 for g and m both long or rather similar gSIINODE a 21 shifts aCe2O + plasma ion source with cooled transfer line Te obtained from the Xe and I decay odd-A : mTe not fed by the decay of I g means to obtain pure collections of gTe a 4 shifts In total : 38 shifts (+ 4)