Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Study of the odd-A, high-spin isomers in
neutron-deficient trans-lead nuclei with
ISOLTRAP
Mass difference
α identification
Shifts
A.N. Andreyev, D. Beck, K. Blaum, Ch. Böhm, Ch. Borgmann,
M. Breitenfeldt, R.B. Cakirli, T.E. Cocolios, F. Herfurth,
A. Herlert, M. Huyse, M. Kowalska, S. Kreim, D. Lunney,
S. Naimi, M. Rosenbusch, S. Schwarz, L. Schweikhard,
J. Stanja, P. Van Duppen, F. Wienholtz, R. Wolf, K. Zuber
INTC Meeting
Februay 4th , 2011
An area of extensive isomerism
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
Shifts
Low- and High-spin isomers
In the region of the nuclear chart around Z = 82 and
N = 104, a prolific number of isotopes present isomerism. In
the even-Z
, odd-A isotopes, these manifests as a low-spin
+
3−
isomer
and a high-spin 13
isomer, interpreted as
2
2
single particles in the νp3/2 and νi13/2 orbitals, respectively,
coupled to the neighbouring even-even core.
Migration of the νi13/2 orbital
. . . or its closest approximation in the migration of the lowest
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
Shifts
13 +
2
state
ISOLTRAP
Mass-difference measurement: textbook case of
70
Cu
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
Shifts
J. Van Roosbroeck et al., PRL 92(2004)112501
ISOLTRAP
Mass-difference measurement: real case of
187
Pb
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
Shifts
C. Weber et al., PLA 347(2005)81-87
ISOLTRAP
Mass-difference measurement: real case of
187
Pb
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
Shifts
Limits
Hg not connected to the
others by α decay;
Pb too low energy;
Po cannot make sufficiently
pure isomeric beams;
Rn too low production rates;
Ra too low production rates;
C. Weber et al., PLA 347(2005)81-87
ISOLTRAP
Mass-difference measurement: real case of
187
Pb
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
Shifts
Limits
Hg not connected to the
others by α decay;
Pb too low energy;
Po cannot make sufficiently
pure isomeric beams;
Rn too low production rates;
Ra too low production rates;
T.E. Cocolios et al., JPG 37(2010)125103
ISOLTRAP
Mass-difference measurement: using polonium
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
N
105
107
109
111
113
115
117
A
187
189
191
193
195
197
199
Pb
E [keV]
33(13)
90(60)#
50#
165#
202.9(7)
319.31(11)
430(7)
A
191
193
195
197
199
201
Po
E [keV]
74(21)
100(30)#
230#
204#
310(2)
424.1(23)
A
Rn
E [keV]
195
197
199
201
203
93(26)
#
180(70)#
#
362(5)
A
201
203
205
Ra
E [keV]
#
#
#
Shifts
Yields from RILIS with a standard UCX target, 1.4 GeV protons from PSBooster, using the Cu vapour
lasers.
i
h
A
N
I
T1/2 [s]
Eα [MeV]
Yield ions
µC
3 −
193
109
0.45
6949
7·101
2
13 + 0.24
7004
1·102
2
195
111
197
113
199
115
3−
2
13 +
2
3−
2
13 +
2
3−
2
13 +
2
4.64
1.92
6606
6699
2.5·104
5.5·104
53
25.8
6282
6385
5.8·105
2·106
312
252
5952
6059
>·106
>·106
α-decay station
identify exotic heavy isotopes
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
Shifts
CRIS Windmill 2.0
UHV standard;
magnetic coupling to
motor outside the
vacuum;
currently being built and
tested in IKS;
expected resolution ≤ 25
keV.
Shifts request
Target: UCX ; Source: RILIS (optionally narrowband)
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
Shifts
193 Po
195 Po
197 Po
199 Po
MR-ToF
1 shift
1 shift
1 shift
1 shift
development
Precision Trap
5 shifts
2 shifts
2 shifts
1 shift
2 shifts
Windmill
2 shifts
1 shift
1 shift
1 shift
We propose to perform this study over two campaigns:
Part 1: 9 shifts
Part 2: 12 shifts
TOTAL: 21 shifts
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
Shifts
The importance of the i13/2 shell
. . . as supported by the δhr 2 i
Polonium
T.E. Cocolios
Motivation
Isomers
νi13/2
Technique
Mass difference
α identification
Shifts