Bulletin #17 January 30, 2002 _/ _/ _/ _/_/_/_/ _/_/_/_/ _/_/ _/_/ _/_/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/_/_/_/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/_/_/_/ _/_/_/_/ ATOMIC MASS DATA CENTER -------------------------------------------------------------------- I - NEWS FROM EXPERIMENTS ON MASSES Determination of QEC of 156Ho with TAS / I.N.Izosimov October 2001 Determination of the beta(EC)-decay total energy from the end point of the total absorption spectra by using total absorption spectrometer (TAS) may be applied for wide range of nuclei. In this work we analyse the parts of spectra with enough high counting per channel. The Q(EC) as a parameter is determined using chi^2-analysis. From the chi^2 minimum the Q(EC) was determined. After linearization, the error delta-Q(EC) was established. Such procedure was used for different energy intervals. In all cases we obtained approximately the same values of Q(EC) but different delta-Q(EC). The optimal energy interval was selected from delta-Q(EC) minimum. We obtained Q(EC)=(4.91±0.15)MeV for 156Ho. http://csnwww.in2p3.fr/AMDC/experimental/156Ho.ps Isochronous Mass Measurements in the ESR / M. Hausmann October 2001 Schottky Mass Spectrometry [T.Radon et al., PRL78 (1997) and T.Radon et al., NPA677 (2000)] of electron cooled heavy ions at the ESR is very successful, but at the same time is limited to nuclides with half-lives of at least a few seconds due to the time needed for electron cooling and for the sampling of the Schottky noise. This is overcome in Isochronous Mass Spectrometry. An isochronous ion optical setting [H.Wollnik, NIMA258 (1987)] of the storage ring ESR has been developed. In this setting the revolution time of a particle is (to first order) energy independent while the dependence on the mass-to-charge ratio (m/q) persists. Thus, ion species of different m/q are separated instantly. The properties of this setting and its applicability to mass measurements have been studied. First mass measurements on long lived fragments of nickel and neon primary beams have been carried out using the Schottky diagnosis. A mass resolving power of 150.000 has been obtained. A time-of-flight detector system has been implemented in the ESR to measure the revolution times of stored single ions within a few ten revolutions (of about 500 ns each) and its operation has been commissioned, showing that the combination of these achievements allows to measure masses of short-lived nuclides. These results are part of M. Hausmann's thesis (Giessen, June 1999) http://csnwww.in2p3.fr/AMDC/experimental/th-hausmann.pdf (full text in German). A summary (in English) of this thesis is published in M.Hausmann et al., NIM A 446 (2000) 569. II - NEWS FROM THEORIES ON MASSES Mass Formula of Koura, Uno, Tachibana, and Yamada / October 2001 We present a table of atomic masses and related quantities obtained from the nuclear mass formula with shell energies calculated by a new method as described in Nuclear Physics A 674 (2000), pp.47-76. This table, is available from the AMDC web site as file: http://csnwww.in2p3.fr/AMDC/theory/Kuty00_m246.dat Each column in this file is as follows; ZZ: proton number NN: neutron number Mcal: calculated mass excess (MeV) Esh: calculated shell energy (MeV) alpha2,alpha4,alpha6: deformation parameters. The definitions of these quantities are appeared in the paper of Nucl. Phys. A 674 (2000), pp.47-76, or RIKEN-AF-NP-394, RIKEN (2001) III - AN EDUCATIONAL WEB SITE ON RADIOACTIVITY An educational Web site on Radioactivity / G. Audi October 2001 A Web site on Radioactivity, in French, has been opened on October 24,2001. There are projects for an English translation. This web site explains the physical phenomenon of radioactivity, tells the history of its discovery and develops on its applications: in everyday's life, at the hospital, at the museum, in the laboratory and in industry. A large section is devoted to nuclear energy and waste management. The "Communiqué de presse" (in French) can be viewed at: http://csnwww.in2p3.fr/AMDC/nucleus/Radio-Presse.txt The URL of this Web site is http://www.laradioactivite.com IV - GENERAL INFORMATION Please send contributions to the next bulletin of the AMDC to: audi@csnsm.in2p3.fr AMDC Web: http://csnwww.in2p3.fr/amdc/ click:"access to files" or: http://csnwww.in2p3.fr/AMDC/ for self-navigation The AMDC bulletin is sent electronically 5 to 8 times per year. To subscribe / unsubscribe please send an email to: audi@csnsm.in2p3.fr Atomic Mass Data Center C.S.N.S.M. (IN2P3-CNRS) Batiment 108 F-91405 Orsay campus (France)