Spin alignment and g-factor measurements with RISING Maria Kmiecik IFJ PAN NZ22 IFJ PAN Review 5-6 Feb. 2009 IFJ PAN Review 5-6 Feb. 2009.

Spin alignment and g-factor Spin alignment and g-factor measurementmeasurementss with RISING with RISING Spin alignment and g-factor Spin alignment and g-factor measurementmeasurementss with RISING with RISING

Maria KmiecikMaria Kmiecik

IFJ PANIFJ PAN

NZ22NZ22

IFJ PAN Review 5-6 Feb. 2009IFJ PAN Review 5-6 Feb. 2009

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

IFJ PAN, Kraków: A. Maj, P. Bednarczyk, M. Ciemała, J. Grębosz, K. Mazurek, W. Męczyński,

S. Myalski, J. Styczeń, M. Ziębliński, MK

GSI Darmstadt: J. Gerl et al. ...

KU Leuven: G. Neyens et al. …

UJ Kraków: R. Kulessa,

UW Warszawa: M. Pfützner,

University of Sofia: D.L. Balabanski et al. …

g-RISING collaborationg-RISING collaboration

Rare Isotope Spectroscopic INvestigation at GSI

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

motivationmotivation

magnetic moments =g*I – probe for investigation of single-particle configuration properties (spin, parity, proton/neutron characters)

spin aligned nuclei – necessary for the magnetic moments study

spin alignment of nuclei with isomeric states produced in the fragmentation reaction has been studied so far only in: light nuclei intermediate energies of projectiles

K. Asahi et al., Phys. Rev. C43, 456 (1991) – 14B (beam 18O at 60 MeV/u) W.-D. Schmidt-Ott et al., Z. Phys. A50, 215 (1994) – 43Sc (beam 46Ti at 500 MeV/u) G. Georgiev et al., J. Phys. G28, 2993 (2002) – 68Ni (beam 76Ge at 61.4 MeV/u) I. Matea et al., Phys. Rev. Lett. 93, 142503 (2004) – 61Fe (beam 64Ni at 54.7 MeV/u)

fragmentation is the important reaction that can be used for production of exotic, e. g. neutron-rich nuclei

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

method - g-factor measurement method - g-factor measurement

Bg NL

))(cos(1),,(

);,,()exp(),,(

22

0

tPABtW

BtWtIBtI

L

TDPAD (time dependent perturbed angular distribution) method

)2sin(43

)(

45

2

2 taa

tR

for

L

))(2cos(43

)(2

2 taa

tR L

),,(),,(

),,(),,()(exp

BtIBtI

BtIBtItR

alignment

Larmore frequency

beam

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

spin alignmentspin alignmentin fragmentation reactionin fusion reaction

oblate alignment (-)

Asahi modelK. Asahi et al.; Phys. Rev. C43 (1991) 456

FRS

selected in the experiment

Is the alignment produced by reaction preserved after transport through FRS?

v0

projectile

target

v

prolate alignment (+)

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

spin alignmentspin alignment

FRS

Is the alignment produced by reaction preserved after transport through FRS?

The spin alignment can be lost due to pick-up of electron(s) by the fully stripped ion when it passes materials in the beam line hyperfine interaction reduces/cancels the reaction-produced spin-orientation

Larger probability of picking-up electrons have heavy nuclei (with larger Z)

In order to minimize lost of spin alignment one can: increase the ion velocity (~ 300 MeV/u) reduce material on the way of transported ion

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

K. Vyvey et al.;Phys. Rev. C69, 064318 (2004)Ch. Stenzel et al., Nucl. Phys. A411, 248 (1983)

goal of the experimentgoal of the experiment

known:known:- lifetime:lifetime: 1.57(6)1.57(6) ss- g-factor:g-factor: - 0.173(2)- 0.173(2)

M. Ionescu-Bujor et al.; Physics Letters B 650 (2007) 141

Do we have alignment in heavy isotopes produced in fragmentation reaction?

192192PbPb

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

beambeam

g-RISING setupg-RISING setup

Al degraderAl degrader

SC41SC41

slitsslits

Pb-wallPb-wall

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

G

C

D

L

K J

A

B

primary beam

Be+Nbtarget

FRSdipoles

FRSdipoles

sc1

we

dg

e

sc2MW

1

MW

2

MU

SIC

valida-tion

veto

plexi + Cu

magnet

TOF

Zx,yx,y x,y

A/Q ~ Br bg/

HPGe clusters

experimentexperiment

Reaction: fragmentation of 238U at 1GeV/u

9Be

g-RISING campaign at GSIg-RISING campaign at GSI

B=0.16T

2.30 2.32 2.34 2.36-60

-40

-20

0

20

40

189Tl188Tl

193Bi194Bi

190Pb

191Pb xf

A/Q

192Pb

2.30 2.32 2.34 2.36-60

-40

-20

0

20

40

gate3gate2

XS

C1

A/Q

gate1

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

final focal plane

A/Q

X

secondary fragments: o 193193Bi,Bi, 194 194BiBio 190190Pb,Pb, 191 191Pb,Pb, 192192PbPbo 188188Tl,Tl, 189 189TlTl

analysisanalysis

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

Consistent with published values: = 1.57(6) sg = - 0.173(2)

Ch. Stenzel et al., Nucl. Phys. A411, 248 (1983);K. Vyvey et al., Phys. Rev. C69, 064318 (2004);M. Jonescu-Bujor et al., Phys. Lett. B650, 141 (2007)

fusion-evaporation exp.

12+ state described by configuration )( 2

2/13i

resultsresults)2sin(

4

3)(

2

2 ta

atR L

= 1.54(9) = 1.54(9) ss|g| = 0.17(1)|g| = 0.17(1) = 1.54(9) = 1.54(9) ss|g| = 0.17(1)|g| = 0.17(1)

aa22 = = 0.12(3)0.12(3)

aa22 = = 0.12(3)0.12(3)

proven feasibility of g-factor studies proven feasibility of g-factor studies in heavy nuclei producedin heavy nuclei produced i in fragmentation of n fragmentation of

relativistic beam relativistic beam

aa22 = = 0.400.40

Yamazaki value for fully aligned spins

aa22 ~ ~ 0.300.30

Alignment Alignment ≈ 30%≈ 30%

M. Kmiecik et al. - to be published

M. Kmiecik, Feb.’09M. Kmiecik, Feb.’09

conclusionsconclusions

g-factor in heavy nucleus was measured for the first time in the fragmentation reaction of relativistic beam

preserved spin alignment was found to be large enough for the feasibility of future g-factor investigations in heavy exotic nuclei