Addendum to Proposal P-242 to the INTC
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Transcript of Addendum to Proposal P-242 to the INTC
Addendum to Proposal P-242 to the INTC
SEARCH FOR NEW CANDIDATES FOR
THE NEUTRINO-ORIENTEDPRECISION MASS SPECTROMETRY
D. Beck, K. Blaum, M. Block, Ch. Böhm, Ch. Borgmann, M. Breitenfeldt, S. Eliseev, V. Fedoseev, S. George, F. Herfurth, A. Herlert, H.-J. Kluge,
M. Kowalska, S. Kreim, D. Lunney, V. Manea, S. Naimi, D. Neidherr, Yu. N. Novikov, M. Rosenbusch, S. Schwarz, L. Schweikhard,
M. Seliverstov, A. Sokolov, J. Stanja, F. Wienholtz, R. N. Wolf, K. Zuber
Spokesperson: Sergey EliseevMax-Planck Institut für Kernphysik, Heidelberg, Germany
MPIK-GSI-Mainz-Leuven-CERN-MSU-FAIR-Orsay-RIKEN-PNPI-Greifswald-Dresden
mn =0m
n =2 eV Qmn
status on antineutrino mass
the smaller the Q-value the higher the sensitivity
3H (Q=18.6 keV) 187Re (Q=2.57 keV)
Recent limit of m(νe) ≈ 2 eV is obtained from the
analysis of the end point of b--decay
There are only two suitable candidates
Limited number of suitable nuclides is a substantial restriction for future experiments!
Lobashev V M et al 1999 Phys. Lett. B 460 227Kraus Ch et al 2005 Eur. Phys. J. C 40 447
QECmn
status on neutrino mass
the smaller the QEC-B the higher the sensitivity
The most recent limit of m(νe) ≈ 200 eV is obtained from the analysis of de-excitation spectrum of electron capture (EC) in 163Ho
There are a lot of potentially suitable candidates !!!
but the choice of the suitable ones is hampered by poor knowledge of their Q-values
B-binding energy of captured electron
De Rujula A et al 1982 Phys. Lett. B 118 429Springer P T et al 1987 Phys. Rev. A 35 679
status on neutrino mass
163Ho is by far the best candidate QEC-B ≈ 0.5 keV
potential candidates
194Hg and 202Pb also arevery promising nuclides !!!
PROPOSAL P-242 (2008)
“A determination of the Q-values of ECin 194Hg & 202Pb by direct Penning trap
mass measurements of 194Hg/Au and 202Pb/Tl “
status of proposal
ISOLTRAP beam times scheduled for IS473Beam time Dedicated
forTarget/ion source Remark
May 2008 202Pb,202Tl UCx/Hot plasma canceled due to power failure
July 2008 194Au UCx/RILIS successful
August 2008
194Hg UCx/Hot plasma by-product of experiment IS461; successful
October 2008
202Pb UCx/Hot plasma by-product of IS463; successful
April 2009 194Hg UCx/Hot plasma unsuccessful; no 194Hg was seen
June 2011 202Pb202Tl
UCx/RILISUCx/Surface ionization
direct measurement of the QEC-value. The QEC-value is measured with insufficient accuracy
Masses of three out of four nuclides have been measured !!! 194Hg/Au and 202Pb
The Q-value of EC in 194Hg has been determined !!!
status of proposal
AME2003 Q-value of EC in 194Hgis (69±14) keV
New Q-value of EC in 194Hg is (29±4) keV
old scheme of EC in 194Hg new scheme of EC in 194Hg
?
QEC – BL1 = (15 ± 4) keV → It is possible to improve the upper limit onneutrino mass from 200 eV to 20 eV with
this nuclide
Eliseev S et al 2010 Phys. Lett. B 693 426
addendum to proposal
In order to determine the Q-value of EC in 202Pb, it remains to only measure the mass of 202Tl
Addendum to Proposal P-242
“Determination of the mass of 202Tl at ISOLTRAPwith an accuracy of 2 keV“
Beam time request
Nuclide Ion Source TargetExpected yield,
ions/mCReference masses № of Shifts
202Tl RILIS UCx 1·105 (RILIS) 133Cs 5*
* The number of shifts requested is based on the experience acquired during the previous runs