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- Mantsinen, M. J., et al.
(author)
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Alpha-tail production with ion-cyclotron-resonance heating of He-4-beam ions in JET plasmas
- 2002
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 88:10
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Journal article (peer-reviewed)abstract
- Third-harmonic ion-cyclotron-resonance heating of He-4-beam ions has produced for the first time on the JET tokamak high-energy populations of He-4 ions to simulate 3.5 MeV fusion-born alpha (alpha) particles. Acceleration of He-4 ions to the MeV energy range is confirmed by gamma-ray emission from the nuclear reaction Be-9(alpha, ngamma) C-12 and excitation of Alfven eigenmodes. Concomitant electron heating and sawtooth stabilization are observed. The scheme could be used in next-step tokamaks to gain information on trapped alpha particles and to test a diagnostics in the early nonactivated phase of operation.
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2. |
- Shergur, J., et al.
(author)
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beta-decay studies of Sn135-137 using selective resonance laser ionization techniques
- 2002
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In: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 65:3
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Journal article (peer-reviewed)abstract
- The decays of the very neutron rich Sn isotopes Sn135-137 were studied at CERN/ISOLDE using isotopic and isobaric selectivity achieved by the use of a resonance ionization laser ion source and mass spectroscopy, respectively. Neutron decay rates, gamma-ray singles, and gamma-gamma coincidence data were collected as a function of time. The half-life (T-1/2) and delayed neutron emission probability (P-n) values of 135 Sn were measured to be 530(20) ms and 21(3)%, respectively. For Sn-136, a T-1/2 of 250(30) ms was determined along with a P-n value of 30(5)%. For Sn-137, a T-1/2 of 190(60) ms and a P-n value of 58(15)% were deduced. Identification of low-energy transitions in Sb-135 was made possible by comparison of laser-on and laser-off gamma-ray spectra. Those data combined with gamma-gamma coincidence spectra were used to construct a level scheme for Sb-135 that includes an unexpectedly low first excited state at 282 keV. A ground state beta branch of 33.2% was measured by following the growth and decay of the Sb-135 daughter. Shell-model calculations are consistent with the observed Sb-135 level structure and can account for a lowered first excited state.
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3. |
- Shergur J, Brown BA, Fedoseyev V, Koster U, Kratz KL, Sweryniak D, Walters WB, Wohr A, Fedorov D, Hannawald M, Hjorth-Jensen M, Mishin V, Pfeiffer B, Ressler JJ, Fynbo HOU, Hoff P, Mach H, Nilsson T, Wilhelmsen-Rolander K, Simon H, Bickley A and the ISOLD
(author)
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Beta-Decay Studies of 135-137Sn using Selective Resonance Laser Ionization Techniques
- 2002
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In: Phys. Rev.. ; C65, s. 34313-
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Journal article (peer-reviewed)
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4. |
- Shergur, J., et al.
(author)
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Decay of Sn-135,Sn-136 isolated by use of a laser ion source and evidence for a more harmonic-oscillator-like nuclear potential
- 2001
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In: Nuclear Physics A. - 0375-9474. ; 682, s. 493C-497C
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Conference paper (peer-reviewed)abstract
- The use of a resonance ionization laser ion source at CERN/ISOLDE has made it possible to study the decay of very neutron-rich Sn135-137. The decay of Sn-135 is found to populate low-energy levels in Sb-135 via direct beta decay and the first excited state in Sb-134 by beta-delayed neutron emission. The level structure of Sb-135 Will be discussed and a possible signature for a more diffuse nuclear surface considered.
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