Bulletin #08                                       November 25, 1999

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                 ATOMIC        MASS        DATA       CENTER

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    I - GENERAL INFORMATION

    Please see the general information given in bulletin #01.

    To  retrieve  one or more of the documents or files available on the
    AMDC, connect to the AMDC by anonymous-ftp:
           ftp csnftp.in2p3.fr    cd pub/AMDC    get document.list
    or access to the AMDC Web:   http://csnwww.in2p3.fr/amdc/
    "document.list"  is  the  comprehensive  list of documents and files
    available from AMDC.

    The  AMDC  bulletin is sent electronically 3 to 5 times per year. To
    subscribe / unsubscribe please send an email to: audi@csnsm.in2p3.fr



    II - NEWS FROM EXPERIMENTS ON MASSES

    New Results from MIT           /      Simon Rainville  November 1999

    New values for the atomic masses of 133Cs, 87Rb, 85Rb, and 23Na were
    recently  measured at MIT with uncertainties less than 0.2 ppb. This
    is  a  factor  of  more  than  100  improvement over the accuracy of
    previously measured values. These results were obtained by isolating
    single  ions  in  a  Penning  trap,  and  carefully  measuring their
    cyclotron  frequencies.  With  the  measurement  of  133Cs,  we have
    increased  the  mass  range  for  sub-ppb measurements done with our
    apparatus by a factor of 3; our mass table extends now from 1 to 133
    amu.

    These  values  are important for new ppb-level determinations of the
    molar  Planck constant NAh and the fine-structure constant. Combined
    with   photon  recoil  measurements  of  h/m(alkali),  they  open  a
    high-precision  route  to  alpha  founded on simple physics and thus
    very  valuable to test the unity of physics and QED. Furthermore, Cs
    and  Rb  are  used  as  reference  masses  for measurements of heavy
    radioactive nuclei.

    The preprint where this work is described is available from the AMDC
    as post-script file "experimental/mit1999.ps" (199 kb).



    III - ADDRESS

    Address:   Atomic  Mass  Data  Center
               C.S.N.S.M. (IN2P3-CNRS)
               Batiment 108
               F-91405 Orsay campus (France)

    Telephone: +33 1 6915 5223   E-mail: audi@csnsm.in2p3.fr
    Telefax:   +33 1 6915 5268   WWW: http://csnwww.in2p3.fr/amdc/