β-decay study of neutron-rich Tl and Pb iso topes

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β-decay study of neutron- rich Tl and Pb isotopes CERN-ISOLDE, Switzerland, E.Rapisarda, J.Kurcewicz, M. Kowalska, V.N. Fedosseev, S. Rothe, , B.A. Marsh INFN, Sezione di Padova and LNL , D. Bazzacco, S. Lenzi, S. Lunardi, F. Recchia, C. Michelagnoli, A. Gottardo, G. de Angelis, J.J. Valiente-Dobón, P. John, D. Napoli, V.Modamio, D. Mengoni, IKS-KULeuven, Belgium, H. De Witte, M.Huyse, P.Van Duppen, R. Raabe, K.Wrzosek-Lipska, C.Sotty Instituto de Fisica Corpuscular, Universita’ de Valencia, Spain A.Algora 1 , University of York, U.K., A.N. Andreyev, D. Jerkins Department of Nuclear Physics and Biophysics, Comenius University, Slovakia S. Antalic 3 , Petersburg Nuclear Physics Institute, Gatchina, Russia, A.E. Barzakh, D.V.Fedorov, M.D. Seliverstov, University of Köln, Germany A. Blazhev 6 , P. Reiter, N. Warr, J. Jolii, University of Manchester,U.K. J.Billowes, T.E. Cocolios, T. Day Goodacre, K.T. Flanagan, I. Strashnov, University of Surrey, U.K., R.Carroll 8 , Z.Podolyak, P.M.Waker, C. Shand, Z. Patel, P.H. Regan University of Jyväskylä, Helsinki Institute of Physics, Finland, T. Grahn, P.T. Greenlees, Z. Janas, J.Pakarinen, P. Rahkila University of Warsaw, Faculty of Physics, Poland, C.Mazzocchi, , M. Pfützner, Institut fur Physik, Gutenberg Universitat, Germany, T. Kron, K.D.A.Wendt, S. Richter 14 Department of Physics, University of Liverpool, U.K., B.Cheal, D. Joss, R. Page, IFIN-HH, Bucharest R. Lica, N. Marginean, R. Marginean, C. Mihai, A.Negret, S. Pascu

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CERN-ISOLDE , Switzerland , E.Rapisarda , J.Kurcewicz , M. Kowalska, V.N. Fedosseev , S . Rothe, , B.A. Marsh - PowerPoint PPT Presentation

Transcript of β-decay study of neutron-rich Tl and Pb iso topes

Page 1: β-decay study of neutron-rich  Tl  and  Pb iso topes

β-decay study of neutron-rich Tl and Pb isotopes

CERN-ISOLDE, Switzerland, E.Rapisarda, J.Kurcewicz, M. Kowalska, V.N. Fedosseev, S. Rothe, , B.A. MarshINFN, Sezione di Padova and LNL , D. Bazzacco, S. Lenzi, S. Lunardi, F. Recchia, C. Michelagnoli, A. Gottardo, G. de Angelis, J.J. Valiente-Dobón, P. John, D. Napoli, V.Modamio, D. Mengoni, IKS-KULeuven, Belgium, H. De Witte, M.Huyse, P.Van Duppen, R. Raabe, K.Wrzosek-Lipska, C.SottyInstituto de Fisica Corpuscular, Universita’ de Valencia, Spain A.Algora1, University of York, U.K., A.N. Andreyev, D. JerkinsDepartment of Nuclear Physics and Biophysics, Comenius University, Slovakia S. Antalic3, Petersburg Nuclear Physics Institute, Gatchina, Russia, A.E. Barzakh, D.V.Fedorov, M.D. Seliverstov, University of Köln, Germany A. Blazhev6, P. Reiter, N. Warr, J. Jolii, University of Manchester,U.K. J.Billowes, T.E. Cocolios, T. Day Goodacre, K.T. Flanagan, I. Strashnov, University of Surrey, U.K., R.Carroll8, Z.Podolyak, P.M.Waker, C. Shand, Z. Patel, P.H. ReganUniversity of Jyväskylä, Helsinki Institute of Physics, Finland, T. Grahn, P.T. Greenlees, Z. Janas, J.Pakarinen, P. RahkilaUniversity of Warsaw, Faculty of Physics, Poland, C.Mazzocchi, , M. Pfützner, Institut fur Physik, Gutenberg Universitat, Germany, T. Kron, K.D.A.Wendt, S. Richter14

Department of Physics, University of Liverpool, U.K., B.Cheal, D. Joss, R. Page, IFIN-HH, Bucharest R. Lica, N. Marginean, R. Marginean, C. Mihai, A.Negret, S. Pascu

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Physical CaseNuclear-Structure beyond 208Pb

N = 126208Pb126Z =82

N=

126

g9/2

Study the development of nuclear structure in the nuclei beyond N=126

What the position of single particle orbitals? What does the effective proton-neutron interaction look like?

Page 3: β-decay study of neutron-rich  Tl  and  Pb iso topes

Physics Motivation

Seniority scheme Experimental level scheme for 210-216Pb, Hg consistent with (g9/2)n dominance low-lying states in odd-mass Tl described as (g9/2)2 (s-1

1/2) or (d-13/2)

Kuo-Herling realistic interaction (T.T.S. Kuo ans G.H. Herling, U.S. Naval Research Laboratory Report N.2258, 1971)

Inclusion of the three-body forces is essential A. Gottardo et al. PRL109, 162502 (2012)

The region around 208Pb has been very difficult to populate experimentally due to its large A and Z.

= 130

g7/2

d5/2

h11/2

d3/2

s1/2

h9/2

f7/2

h9/2

i13/2

p3/2

f5/2

g9/2

p1/2

= 81

50

82126

82

Lifetime measurements in 211,212,213Tl Lifetime measurements in 218,219Bi Three high-spin isomers in 211Pb and decay scheme 8+ isomers in 208Hg and 210Hg 8+ isomers in 212,214,216Pb 17/2+ isomer in 209Tl (95 ns) -decay of 215Pb, 215,216,217,218Bi

N. Al-Dahan et al., Phys. Rev. C80 (2009) 061302; A. Gottardo et al., Phys. Lett. B725 (2013) 292

A. Gottardo et al., Phys. Rev. Lett. 109 (2012) 162502

N. Al-Dahan et al., Phys. Rev. C80 (2009) 061302

G.J. Lane et al., Phys. Lett. B 606 (2005) 34

G. Benzoni et al., Phys. Lett. B715 (2012) 293

H. De Witte et al., Phys. Rev. C87 (2013) 067303; J. Kurpeta et al., Eur. Phys. J. A18 (2003) 31 H. De Witte et al., Phys.Rev. C 69, 044305 (2004)

f7/2

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Half-life of 211-215Tl

211Pb

g

g

211Bi

t1/2=88 s Q = 4.4 MeV

t1/2=36.1m

t1/2=2.14m

211Tl(1/2+)

G. Benzoni et al., Phys. Lett. B715 (2012) 293

(9/2+)

(9/2-)

211Tl t1/2=88 s 50% uncertainty212Tl t1/2=96 s 50% uncertainty213Tl t1/2=46 s 100% uncertainty

The -decay would be dominated by Gamow-Teller transitions to high energy states (partially occupied neutron shells 3d5/2 or 4s1/2 above g9/2)

State-of-the-art models used in r-process calculations underestimate the experimental results

Data collected at GSI (not published) show a change in structure with respect to 211Pb Low-lying states in the daughter Pb can be populated and studied.

= 130

g7/2

d5/2

h11/2

d3/2

s1/2

h9/2

f7/2

h9/2

i13/2

p3/2

f5/2

g9/2

p1/2

= 81

50

82126

82

f7/2

i11/2i13/2

Half-life measurements will shed further light on the discrepancy

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N. Al-Dahan et al., Phys. Rev. C80 (2009) 061302

Long-living isomers in 211,213Tl

- 211,213Tl: Experimental evidence (data not published) of different structure with respect to 209Tl;

- Shell model calculations suggest inversion of 9/2+ and 7/2+

- SPIN TRAP Long living isomers in 211,213Tl???

A. Gottardo, PhD thesis, unpublished

The occurrence of many high-spin single particle orbitals in the nuclei to be explored will give rise to several isomeric states

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G.J. Lane et al., Phys. Lett. B 606 (2005) 34

Long-living isomers in 213Pb

- experimental evidence of short-lived isomeric decay;- The decay of the isomers shows a change in nuclear structure compared to 211Pb- If (27/2)+ moves below (23/2)+ SPIN TRAP Long living isomers in 213Pb ???

A. Gottardo, PhD thesis, unpublished

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Proposed experiment

Laser Spectroscopy AIM o identify long-living isomers in 211,213Tl

and 213Pb

Decay Spectroscopy AIM o lifetime of 211-215Tl with 10% uncertainity o decay scheme in 211-215Pb by -decay Tl

4 Clovers 1 Miniball Triple cluster:

Total γ detection efficiency is about 8-9% at 1.3MeV

Total detection efficiency is about 60%

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Beam Time Request

Isotope Rate on tape /s Time Expected n. -g counts

211Tl 540 1 shift 1 10∙ 5

212Tl 225 1 shift 6 10∙ 4

213Tl 90 1 shift 3 10∙ 4

214Tl 36 3 shifts 3 10∙ 4

215Tl 12 6 shifts 2 10∙ 4

213Pb 250 3 shifts 2 10∙ 5

215Pb Reference 47 (*)

(*) H. De Witte et al., Phys. Rev. C87 (2013) 067303

UCx Target + quartz transfer line + LIST target Expected strong Fr and Ra contamination up to 1000 x surface ion suppression New development in RILIS micro beam gate = 100 x Surface ion suppression

A=214-215: Pulsed-release technique relatively longer lifetime of the -decaying isotopes of interest compared to the significantly shorter lived Fr and Ra;

• Laser Ionization: RILIS (27% and 7% for Tl and Pb respectively) We request therefore:

Need 21 Shifts measurement2 shifts for tuning the laser to Pb and Tl4 shifts for laser - spectroscopy

15

Successfully used to study 219Po (IS456)

T1/2 measurements 20% duty cycle

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CollaborationCERN-ISOLDE, Switzerland, E.Rapisarda, J.Kurcewicz, M. Kowalska, V.N. Fedosseev, S. Rothe, , B.A. MarshINFN, Sezione di Padova and LNL , D. Bazzacco, S. Lenzi, S. Lunardi, F. Recchia, C. Michelagnoli, A. Gottardo, G. de Angelis, J.J. Valiente-Dobón, P. John, D. Napoli, V.Modamio, D. Mengoni, IKS-KULeuven, Belgium, H. De Witte, M.Huyse, P.Van Duppen, R. Raabe, K.Wrzosek-Lipska, C.SottyInstituto de Fisica Corpuscular, Universita’ de Valencia, Spain A.Algora1, University of York, U.K., A.N. Andreyev, D. JerkinsDepartment of Nuclear Physics and Biophysics, Comenius University, Slovakia S. Antalic3, Petersburg Nuclear Physics Institute, Gatchina, Russia, A.E. Barzakh, D.V.Fedorov, M.D. Seliverstov, University of Köln, Germany A. Blazhev6, P. Reiter, N. Warr, J. Jolii, University of Manchester,U.K. J.Billowes, T.E. Cocolios, T. Day Goodacre, K.T. Flanagan, I. Strashnov, University of Surrey, U.K., R.Carroll8, Z.Podolyak, P.M.Waker, C. Shand, Z. Patel, P.H. ReganUniversity of Jyväskylä, Helsinki Institute of Physics, Finland, T. Grahn, P.T. Greenlees, Z. Janas, J.Pakarinen, P. RahkilaUniversity of Warsaw, Faculty of Physics, Poland, C.Mazzocchi, , M. Pfützner, Institut fur Physik, Gutenberg Universitat, Germany, T. Kron, K.D.A.Wendt, S. Richter14

Department of Physics, University of Liverpool, U.K., B.Cheal, D. Joss, R. Page, IFIN-HH, Bucharest R. Lica, N. Marginean, R. Marginean, C. Mihai, A.Negret, S. Pascu

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5 μs beam gating test

Narrow laser-ion bunch width + micro beam gate tests

Laser-ion time structure:5 μS FWHM!

Ga massmarker

High Ω cavities:1. Thin graphite 2. Pyrolytic graphite 3. Sigradur ‘glassy’ graphite ☐4. Pulsed heating for higher voltage ☐

Ga

0.0000 0.0001 0.0002

0

100

200

300

Cou

nts

Time (s)

6.5 V Voigt Fit

Model VoigtEquation y = nlf_voigt(x,y0,xc,A,wG,wL);

Reduced Chi-Sqr

21.57725

Adj. R-Square 0.99118Value Standard Error

Peak1(H) y0 0.80691 0.13008Peak1(H) xc 2.92636E-5 9.17292E-9Peak1(H) A 0.00151 1.06434E-5Peak1(H) wG 4.92994E-6 6.68324E-8Peak1(H) wL 5.8493E-7 9.11171E-8Peak1(H) FWHM 5.25016E-6 1.80362E-8Peak2(H) y0 0.80691 0.13008Peak2(H) xc 1.29282E-4 9.32479E-9Peak2(H) A 0.00151 1.0731E-5Peak2(H) wG 4.99076E-6 6.687E-8Peak2(H) wL 5.24769E-7 9.18146E-8Peak2(H) FWHM 5.27728E-6 1.82598E-8

0.00000 0.00002 0.00004 0.00006 0.00008 0.00010

0

200

400

600

800

1000

Cou

nts

Time (s)

1 μs beam gate is possible!

= 100 x Surface ion

suppression!

RILIS ionization

scheme

Solid-state switch~ 500 V @ 10 kHz

Courtesy of Richard Catherall

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210 211 212 213 214 215 216 217 2181E-07

1E-06

1E-05

1E-04

1E-03

1E-02 Tl_EPAX3_HTl_Hector_9BETl_COFRA_9BeTl_ABRABLATl_EPAX3_9Be

Mass

Cros

s Se

ction

s (m

barn

)

Tl isotopes

210 211 212 213 214 215 216 217 218

1E-06

1E-05

1E-04

1E-03

1E-02 Pb_EPAX3_H

Pb_Hector_9Be

Pb_COFRA_9Be

Pb_ABRABLA

Pb_EPAX3_9Be

Mass

Cros

s Sec

tions

(mba

rn)

Pb isotopes

540 ions/sec * 8h *3600 sec * 0.09 * 0.6 * 0.2 = 1.7 * 10^5

9% = gamma efficiency at 1.3 MeV60% = beta efficiency20% duty cycle

Page 12: β-decay study of neutron-rich  Tl  and  Pb iso topes

Courtesy of T.E. Cocolios

proton in s1/2 => mu = + 2.793 mu_N => g-factor = + 5.586neutron in g9/2 => mu = - 1.913 mu_N => g-factor = - 0.429 The additivity rule is given as:g_emp (I = Jp + Jn) = 0.5 * { gp + gn + (gp - gn) * (Jp*[Jp+1] - Jn*[Jn+1]) / (I*[I+1]) } = 2.58 + 3 * (3 - 4*Jn*[Jn+1]) / (4*I*[I+1])g_emp (9/2 = 1/2 + 4) = + 0.24 => mu = + 1.09 mu_Ng_emp (13/2 = 1/2 + 6) = +0.04 => mu = + 0.24 mu_Ng_emp (17/2 = 1/2 + 8) = -0.07 => mu = - 0.61 mu_N

The hyperfine parameters become A( 1/2) = 36 336 MHzA( 9/2) = 1 575 MHzA(13/2) = 240 MHzA(17/2) = - 467 MHz

We can definitely differentiate between the ground state and an isomer, but probably not tell which isomer we have.

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J = 1/2 -> 3/2 (for the 276.8 nm transition)Tl, I=1/2: using 205gTl, A = 21.31 GHz, mu = 1.638 mu_NTl, I=9/2: using 193mTl, A = 5.583 GHz (from Barzakh et al, PRC 2013)Tl, I=17/2: using 215Ac, mu = 8 mu_N => A = 6.122 GHz (using 205gTl as reference)0 GHz isotope shift between the isomers.1 GHz Gaussian x 1 GHz Lorentzian sigma.

Courtesy of T.E. Cocolios

Hyperfine Structure in 211Tl

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LIST target performances

D.A. Fink et al. submitted to NIMB

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Old run at ISOLDE in 2000 GPS separatorA= 215Laser tuned on Pb

Hilde de Witte, PhD thesis, KULeuven 2004

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Pb207Pb206 Pb208

Bi209

Tl205

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-spectroscopy: Experimental Setup

Windmill Chamber

Annular Si Si

pure 30 keV Tl beam from RILIS+ISOLDEIntensity = 104 pps

C-foils20 mg/cm2

Si detectors

SiAnnular Si

ff

ff

a

30 keV beam from ISOLDE

C-foil

Ge detector #1

Page 18: β-decay study of neutron-rich  Tl  and  Pb iso topes

technique based on in-source laser spectroscopy (Ü. Köster et al., NIM B, 160, 528(2000); L. Weissman et al., PRC65, 024315(2000)). set the laser frequency to select and maximize the production of the isomer of interest.

Isomeric Beams @ ISOLDE

2-

7+

10-

Inte

nsity

(a.u

.)

Frequency of the first transition (cm-1)

Two SET of DATA

No laser: Tl is Surface Ionized mixture of 2-, 7+, 10-

With laser: Laser set on 10- enhanced 10- state

Page 19: β-decay study of neutron-rich  Tl  and  Pb iso topes

Tl - Surface ionizedTl – laser ionized

445374

506

184Hg184Au

184Pt

184Pt

184Ir

2+ 0+

366 keV

192Au

4+ 2+

287 keVSi

ngle

γ-

sp

ectru

m

Page 20: β-decay study of neutron-rich  Tl  and  Pb iso topes

506 keV

445 keV374 KeV

LifeTime II

T1/2 = 50(0.39) ms

1/10 of the expected 500 ms