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In-source laser spectroscopy of Pb, Bi and Po isotopes at ISOLDE. Maxim SELIVERSTOV Institut für Physik, Johannes Gutenberg Universität, Mainz Petersburg Nuclear Physics Institute, Gatchina. Charge Radii around Z = 82 and N = 104 In-source resonant photoionization spectroscopy at ISOLDE - PowerPoint PPT Presentation
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In-source laser spectroscopy of Pb, Bi and Po isotopes at ISOLDE
Charge Radii around Z = 82 and N = 104In-source resonant photoionization spectroscopy at ISOLDE182-190Pb: charge radii, magnetic moments…189,191Bi: isotope shifts and magnetic moments Po: photoionization schemes and yield testsDiscussion and outlook
Maxim SELIVERSTOVInstitut für Physik, Johannes Gutenberg Universität, MainzPetersburg Nuclear Physics Institute, Gatchina
Contents:
ISOLDE Workshop and Users meeting 2006/200712-14 February 2007 CERN
Level systematics for the neutron-deficient lead isotopes.R. Julin et al., J. Phys. G: Nucl. Part. Phys. 27 (2001)
100 105 110 115 120 125 130
Pt (Z = 78)
Bi (Z = 83)
Po (Z = 84)
Hg (Z = 80)
N =
10
4
N =
12
6
r 2 ,
fm2
N
Ground state Isomer Droplet model prediction
Pb (Z = 82)
= 0.1 fm2
Charge radii below and above Z = 82
???
???
???
nuclear ground and isomeric state properties : δ r 2
98 100 102 104 106 108 110 112 114 116 118 120 122
N
In-source resonant photoionization spectroscopy at ISOLDE
I , Q S
Isotope shift
r 2
Procedure:• measurement of radioactive Pb isotopes• measurements of stable 206,207,208Pb• reference measurements Advantages:• sensitivity: e.g. 183Pb 10 atoms/s at resonanceLimitation:• large Doppler broadening
Laser Ion Source (LIS)
target
ionizer
Laser beams
Mass separator
Pb: atomic spectroscopy
35285.7 35286.0 35286.3 35286.6 35286.9 35287.2 35287.50
10000
20000190Pb
wavenumber, cm-1
10 GHz
0
2000
4000 188Pb
0
500
1000
1500 187Pb I = 13/2
187Pb I = 3/2
189Pb I = 13/2 189Pb I = 3/2
0
5000
10000 186Pb
co
un
ts
0
500
1000
1500 185Pb I = 13/2
185Pb I = 3/2
0
500
1000
1500
184Pb
0
500
1000
183Pb I = 13/2
183Pb I = 3/2
0
20
40
60
182Pb
0
4000
8000
Isotope shift A,A’:
A,A’= F * A,A’ + (NMS+SMS)
F = 20.26(18) GHz.fm-2
MS =0 .19(25)*NMS(Anselment et al, NPA451 (1986) 471)
Rms charge radius :
A,A’ = r 2 + C2r 4 + … = 0.93 r 2
Relative line position (Hyperfine splitting) hyperfine constants A & B μI & (QS) :A = A (μI , I ), B = B (QS , I )
182Pb: T1/2= 55 msYield: ~1 s-1
189Pb: combination of nuclear and laser spectroscopy
3 -lines belonging to the 189Pb decay have been observed with energies: 5727, 5764 and 5619 keV
40 gamma lines belonging to the β/EC decay of 189Pb have been identified: 386, 480, 700, 399....and 667keV are the main ones.
New isomer identified (I = 3/2)Alpha decay scheme has been established
35286,2 35286,4 35286,6 35286,8 35287,0 35287,20,0
0,2
0,4
0,6
0,8
1,0
1,2
sig
nal,
no
rmaliz
ed
wavenumber, cm-1
High spin isomer (I = 13/2), 480 keV Low spin isomer (I = 3/2), 667 keV
Ground state characteristics of 183–190Pb
Reference value r2190,208 = -0.840(10)
fm2
S.B. Dutta et al., Z. Phys. A 341, 39 (1991)
Isotope I *A,208(GHz) **A (GHz) *r2A,208 (fm2)*** ** (n.m.)
182Pb 0+ -24.56(25) — -1.299(12) —
183m1Pb 3/2– -22.95(15) -5.742(25) -1.2145(75) -1.158(5)
183m2Pb 13/2+ -23.54(15) -1.423(6) -1.2455(75) -1.245(5)
184Pb 0+ -21.74(10) — -1.150(5) —
185m1Pb 3/2– -20.66(15) -5.652(25) -1.0930(75) -1.141(5)
185m2Pb 13/2+ -21.26(15) -1.405(12) -1.1245(75) -1.229(10)
186Pb 0+ -19.81(10) — -1.048(5) —
187m1Pb 3/2– -18.78(12) -5.584(25) -0.993(6) -1.127(5)
187m2Pb 13/2+ -19.37(12) -1.383(6) -1.025(6) -1.210(5)
188Pb 0+ -17.57(12) — -0.930(6) —
189m1Pb 3/2– -16.82(15) -5.36(4) -0.8904(75) -1.081(8)
189m2Pb 13/2+ -17.36(20) -1.374(7) -0.9184(75) -1.202(7)
190Pb 0+ -15.86(10) — -0.839(5) —
* H. de Witte et al., „Nuclear charge radii of neutron deficient lead isotopes beyond N=104 mid shell investigated by in-source laser spectroscopy”, to be published in PRL, 2007 ** Preliminary
*** Errors due to the isotope shifts measurements‘ uncertainties are given only. The total errors are 0,013 fm2
for 183-185Pb and 0.010 fm2 for heavier isotopes.
Nuclear magnetic moments
Magnetic moments for the neutron deficient odd-A lead isotopes. The theoretical curve, labelled "Bauer '73", is taken from Bauer R. et al., Nucl. Phys. A 209 (1973), 535.
100 102 104 106 108 110 112 114 116 118-2,0
-1,9
-1,8
-1,7
-1,6
-1,5
-1,4
-1,3
-1,2
-1,1
-1,0
-0,9
m
ag
neti
c m
om
en
t, n
.m.
N
Dutta'91 (I = 13/2+)
This work (I = 13/2+)
This work (I = 3/2-)
Hg (I = 13/2+)
Schmidt line
Bauer'73
1i13/2
3p3/2
Charge radii for Pb chain
our data
The experimental error bar is smaller than the symbol size. The distance between the different chains is chosen arbitrarily for better display. One minor division on the vertical scale corresponds to 0.1 fm2
.
100 105 110 115 120 125 130
Pt (Z = 78)
Hg (Z = 80)
N =
104
N =
126
r
2 ,
fm2
N
Ground state Isomer Droplet model prediction
Pb (Z = 82)= 0.1 fm2
182-190Pb charge radii: experiment
100 102 104 106 108 110 112
-1.4
-1.2
-1.0
-0.8
-0.6
r2 A
,208
, fm
2
I = 0 low spin I = 3/2 high spin I = 13/2literature dataDroplet Model prediction
|2| = 0.2 |
2| = 0.15
|2| = 0.1
|2| = 0
NH. de Witte et al., „Nuclear charge radii of neutron deficient lead isotopes beyond N=104 mid shell investigated by in-source laser spectroscopy”, to be published in PRL, 2007
182-190Pb charge radii: theoretical models
100 102 104 106 108 110 112
-1.4
-1.2
-1.0
-0.8
-0.6
r2 A
,208
, fm
2
MF MF* IBM
|2| = 0.2 |
2| = 0.15
|2| = 0.1
|2| = 0
N
Beyond Mean Field (MF*)Reduced pairingM. Bender et al., Phys. Rev. C 73, 034322 (2006).
Beyond Mean Field (MF)M. Bender et al., Phys. Rev. C 69, 064303 (2004).
H. de Witte et al., „Nuclear charge radii of neutron deficient lead isotopes beyond N=104 mid shell investigated by in-source laser spectroscopy”, to be published in PRL, 2007
Interacting Boson Model (IBM)J. Pakarinen et al., to be published (2006).V. Hellemans et al., Phys. Rev. C 71, 034308 (2005).R. Fossion et al., Phys. Rev. C 67, 024306 (2003).
Bi: atomic spectroscopy
IP = 58761.65 cm-1
6p3 4So3/2
Ground state
6p27s 4P1/2
32588.22 cm-1
Continuum
= 306.770 nm
= 555.205 nm
= 510.554 nm and = 578.213 nm
(CVL)
209Bi I = 9/2F = 5
F = 4
Hyperfine splitting
24.6 GHz
F3456
6.6 GHz
Bi 32586.9 32587.2 32587.5 32587.8 32588.1 32588.40
2000
4000
6000
wavenumber, cm-1
191Bi (I = 1/2)
10 GHz
0
5000
10000
15000191Bi (I = 9/2)
cou
nts
0
2000
4000
6000 189Bi (I = 9/2)
189,191Bi: isotope shifts
105 110 115 120 125 130
-25
-20
-15
-10
-5
0
5
10
, G
Hz
N
literature data
9/2- (ground state)
1/2+ (isomer)
N =
126
our data
Isotope 209,A , GHz
189Bi (I =9/2-) -21.8(3)191Bi (I =9/2-) -20.4(3)191Bi (I =1/2+) -17.9(3)
preliminary
189,191Bi: charge radii
From the comparison of isotopes shifts of Bi and Pb: F = 27(3) GHz/fm2
P. Campbell et al., Phys. Lett. B 346 (1995) 21
105 110 115 120 125 130
-1.2
-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
r A
,209 ,
fm
2
2= 0.15
2= 0.1
N
literature data
9/2- (ground state)
1/2+ (isomer) droplet model prediction
N =
126
2= 0
our data
No reliable values for electronic factor and specific mass shift constant
preliminary
MCDF calulations are under wayS. Fritsche (Univ. of Kassel)
Bi: magnetic moments
105 110 115 120 125 1303.00
3.25
3.50
3.75
4.00
4.25
,
N
N
N =
126
our dataIsotope A, GHz , N
189Bi (I = 9/2-) -0.405(4) 3.73(4)191Bi (I =
9/2-)-0.403(3) 3.71(3)
191Bi (I = 1/2+) -1.45(2) 1.49(2)Reference:
189Bi (I =9/2-)
-0.44697(4)
4.1106(2)
preliminary
Po: photoionization schemes and yield test
ContinuumIP=67885.3 cm-1
6p4 3P2
6p37s 5S2
6p37p 5P2
6p37s 3S1
6p38p ? 10
6p38p ? 12
255.8 nm245.011 nm
843.38 nm 538.89 nm532.34 nm
510.6 nm 510.6 nm IsotopeHalf life,
sYield,
Atoms/μC
193gPo 0.42 7101
193mPo 0.24 1102
194Po 0.392 2.5103
195gPo 4.64 2104
195mPo 1.92 5104
196Po 5.8 4.7105
197gPo 53.6 2.5105
197mPo 25.8 1.75106
198Po 106.2 7106
a bPo yields (scheme „a“)
Conclusions & future perspectives
Laser spectroscopy and nuclear structure:Extention of laser spectroscopy studies to the very neutron deficient isotopes (and isomers) of Pb and Bi Extention of Pb charge radii systematics beyond mid-shell (e.g. 182Pb, T1/2= 55 ms)Comparison with calculations: Ground states of Pb remains spherical189Pb decay scheme has been established189Pb low spin isomer identifiedPhotoionization scheme for Po was developed
Method:Improved precision & reproducibility of in-source laser spectroscopy techniqueUltra high sensitivity
Future:Extension to other elements e.g. Po isotopes
CERN-ISOLDE project IS407: Study of the neutron deficient Pb and Bi isotopes by simultaneous atomic- and nuclear- spectroscopy
A. Andreyev, N. Barré, M. Bender, J. Billowes, T.E. Cocolios, S. Dean, D. Fedorov, V.N. Fedoseyev, L.M. Fraile, S. Franchoo, J. Genevey, V. Hellemans, P.H. Heenen, K. Heyde, G. Huber, M. Huyse, A. Ionan, H. Jeppesen, K. Johnston, U. Köster, Yu. Kudryavtsev, P. Kunz, S.R. Lesher, B.A. Marsh, I. Mukha, B. Roussière, J. Sauvage, I. Stefanescu, E. Tengborn, K. Van de Vel, J. Van de Walle, P. Van Duppen, Yu.M. Volkov, H. De Witte
CERN-ISOLDE project IS407: Study of the neutron deficient Pb and Bi isotopes by simultaneous atomic- and nuclear- spectroscopy
A. Andreyev, N. Barré, M. Bender, T.E. Cocolios, S. Dean, D. Fedorov, V.N. Fedoseyev, L.M. Fraile, S. Franchoo, J. Genevey, V. Hellemans, P.H. Heenen, K. Heyde, G. Huber, M. Huyse, A. Ionan, H. Jeppesen, K. Johnston, U. Köster, Yu. Kudryavtsev, P. Kunz, S.R. Lesher, B.A. Marsh, I. Mukha, B. Roussière, J. Sauvage, I. Stefanescu, E. Tengborn, K. Van de Vel, J. Van de Walle, P. Van Duppen, Yu.M. Volkov, H. De Witte,
CERN Isolde Institut für Physik, University of Mainz,
Germany Institut de Physique Nucléaire, Orsay , France
Instituut voor Kern- en Stralingsfysica, K.U. Leuven, Belgium
Petersburg Nuclear Physics Institute, Gatchina, Russia
Oliver Lodge Laboratory, University of Liverpool, Liverpool, U.K.
LPSC Grenoble , France