Masses of tripline nuclei

Frank Herfurth, ISOLDE/CERN

Mass measurements

ReactionA(a,b)B

Q = MA + Ma – MB – Mb

Alpha-decayA B + Q = MA– MB – M

Time of flight TOFI (LANL) SPEG/CSS2 (Ganil) SARA (ISN) ESR (GSI)

Cyclotron frequency Penning traps MISTRAL (ISOLDE)

Schottky noise analysis ESR (GSI)

INDIRECTINDIRECT DIRECT (mass spectrometry)DIRECT (mass spectrometry)

ISOLTRAP

G. Bollen et al., NIM A 368 (1996) 675H. Raimbault-Hartmann, NIM B 126 (1997) 378

F. Herfurth et al., NIM A 469 (2001) 254

accumulation & bunching of

ISOLDE 60 keV beam

coolingisobar separation

Rm

m

1 105

determination of cyclotron frequency

Rm

m

5 106

1m

Bunches,3keV energy

60keV ISOLDE-

ion beam

1 cm

5 cm

60 000 V

B = 4.7 T

B = 6 T

Linear RFQ trap

Past

Required Yield Half-life Relative mass accuracy yT1/2 m/m

103

104

105

101

102

100ms

1s

10s

1ms

10ms

10-8

10-7

10-6

10-10

10-9

Future

32Ar 74Rb 34Ar

Present

ISOLTRAP performance

ISOLTRAP measurements

74Rb

32, 34Ar

76Sr

132Sn

1995 ... 1999

72Kr

74Rb

72Kr

76Sr

132Sn

216Bi

32, 34Ar

2000 .. 2002

Highlights:

ISOLTRAP measurements

150Ho and the dripline

NEUTRONS

PR

OT

ON

S

150Ho

150Ho is an anchor point for long decay chains

Influence of ISOLTRAP data

-1500

-1000

-500

0

500

1000

1500

2000

2500

81 83 85 87 89 91 93 95

NEUTRON NUMBER N

Sp

[keV

]

Liran +Zeldes

Ho

Tm

Lu Ta ReIr Au Tl

150Ho

149Ho

151TmAME95 excl. TRAP(-chain to150Ho)

AME95 incl. TRAP

Argonne

Dripline changed by the ISOLTRAP measurement of 150Ho

rp-process above Z = 32N=Z

Ge70 Ge72 Ge73 Ge74

Se74

As75

Ge76

Se76 Se77 Se78

Kr78

Br79

Se80

Kr80

Br81

Kr82

Sr84

P

P

P

Ge62 Ge63

As63

Ge64

As64

Ge65

As65

Se65

Ge66

As66

Se66

Ge67

As67

Se67

Br67

Ge68

As68

Se68

Br68

Ge69

As69

Se69

Br69

Kr69

As70

Se70

Br70

Kr70

Ge71

As71

Se71

Br71

Kr71

Rb71

As72

Se72

Br72

Kr72

Rb72

As73

Se73

Br73

Kr73

Rb73

Sr73

As74

Br74

Kr74

Rb74

Sr74

Ge75

Se75

Br75

Kr75

Rb75

Sr75

As76

Br76

Kr76

Rb76

Sr76

Ge77

As77

Br77

Kr77

Rb77

Sr77

Y77

Ge78

As78

Br78

Rb78

Sr78

Y78

As79

Se79

Kr79

Rb79

Sr79

Y79

Br80

Rb80

Sr80

Y80

Kr81

Rb81

Sr81

Y81

Rb82

Sr82

Y82

Rb83

Sr83

Y83 Y84 Y85

34

35

36

37

38

Z = 39

(H. Schatz et al. Phys. Rep. 294 (1998) 167)

possible waiting points

possible rp - process main path

mass excess not yet measured (AME95)

Mass model – experiment comparison

H. Schatz et al. Phys. Rep. 294 (1998) 167

mass number A

possible waiting point

Sr and Kr results

0

ISOLTRAP

AME95

CSS2 (GANIL)A.S. Lalleman et al., Hyp. Int. 132 (2001) 315

0

ISOLTRAP

AME95

possible waiting point

- correlation – 32Ar decay

E.G. Adelberger et al., Phys. Rev. Lett. 83 (1999) 1299

0

2

4

6

8

10

MeV

31S32Cl

32Ar

IAS

+

p

0+,2

0+,2

1/2+

32Ar 32Cl* 31S

e+

R

Precursor

p

Intrinsic shape of the proton-group

a = +1

a = -1

32Ar – search for scalar currents

present limit:a = 0.9989 ± 0.0052(stat) ± 0.0039(sys)

but Q from IMME and:a/Q = -1.2·10-3 keV-1

0

2

4

6

8

10

MeV

31S32Cl

32Ar

IAS

+

p

0+,2

0+,2

1/2+

32Ar 32Cl* 31S

e+

R

Precursor

p

-40 -30 -20 -10 0 10 20 3080

100

120

140

160

180

200

220

32Ar

Me

an

TO

F ( s

)

RF

- 2842679 (Hz)

m/m ~ 1·10-7, i.e. m ~ 3 keV

371 ions, Tobs = 100ms

ISOLTRAPISOLTRAP

Summary

Direct and indirect techniques are needed to access dripline nuclei

ISOLTRAP provides both very precise measurements to anchor long

decay chains direct access to nuclei very close to the

dripline

The ISOLTRAP collaboration

Dietrich Beck

Klaus Blaum

Jürgen Kluge

Daniel Rodríguez

Christoph Scheidenberger

Günther Sikler

Christine Weber

NSCL/MSU EastLansing

Georg Bollen

Stefan Schwarz

GSI Darmstadt CERN Geneva

Alban Kellerbauer

Markku Oinonen

Frank Herfurth

Emanuel Sauvan

LMU Munich

Friedhelm Ames

Michael Kuckein

Sylvain Henry

Jurek Szerypo

McGill Univ. Montreal

Robert B. Moore

CSNSM Orsay

Georges Audi

David Lunney

Univ. of Jyväskylä

Veli Kolhinen

and the ISOLDE collaboration