contentm(28si)= 27.976 926 532 6 u δm = 0.000 000 001 9 u rel. precision = 6x10-11 distance...

www.quantum.physik.uni-mainz.de/mats/

ContentKlaus Blaum: University of Mainz and GSI Darmstadt

High-precision Penning trap experiments for fundamental studies

Motivation and history

Experimental setup and measurement procedure

Summary

High-precision g-factor measurements

High-precision mass measurements

Seattle, Fundamental Symmetries, 19.09.2007


Part I

High-precisionmass measurements


Requirements for mass spectrometry

B(Z,N) = [(Nmn + Zmp + Zme – m(Z,N)]·c2

= N ·

– binding energy

+ Z · + Z ·

High-accuracy mass measurements allow one to determine the atomic and nuclear binding energies reflecting all forces in the atom/nucleus.

K. B., Phys. Rep. 425, 1-78 (2006)


Requirements for mass spectrometryHigh-accuracy mass measurements allow one to determine the atomic and nuclear binding energies reflecting all forces in the atom/nucleus.

δm/m

General physics & chemistry ≤ 10-5

Nuclear structure physics- separation of isobars

≤ 10-6

Astrophysics- separation of isomers

≤ 10-6

Weak interaction studies ≤ 10-8

Metrology - fundamental constants ≤ 10-9

CPT tests ≤ 10-10

QED in highly-charged ions- separation of atomic states

≤ 10-11

K. B., Phys. Rep. 425, 1-78 (2006)


Precision: A brief history of mass spectrometry

1930 1940 1950 1960 1970 1980 1990 2000 201010-12

10-11

10-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

Mas

s U

ncer

tain

ty

δm/m

year

28Si

PTMS

Reaction Q

RF Spectrometers

MassSpectrographs

single ion

ion cloud

m(28Si)= 27.976 926 532 6 uδm = 0.000 000 001 9 uRel. Precision = 6x10-11

Distance Mainz-Seattle8000km ± 0.5mm

SMILETRAP, MIT-TRAP (now at FSU), Seattle-TRAP, Mainz-TRAP

38Ca (T1/2 = 440ms)

CPT, ISOLTRAP, JYFLTRAP, LEBIT, SHIPTRAP


Penning trap facilities worldwide

K.B., Phys. Rep. 425, 1 (2006)


Principle of Penning trap mass spectrometry

Cyclotron frequency:

Bmqfc ⋅⋅=

π21

B

q/m

PENNING trapStrong homogeneous magnetic fieldWeak electric 3Dquadrupole field

z0

r0

ring electrode

end capTypical frequenciesq = e, m = 100 u,B = 6 T⇒ f- ≈ 1 kHz

f+ ≈ 1 MHz

Brown & Gabrielse, Rev. Mod. Phys. 58, 233 (1986)


Time-of-flight ion cyclotron resonance detection

MCPDetector

(1) Excitation of theion motion

(3) TOF measurement

(2) Energy conversion

e

e

mmmm

ff

--

=refc

refc,Determine atomic mass from frequency ratio

with a well-known “reference mass”.

Bmq

πf 21

=c

Centroid:

0 1 2 3 4 5 6 7 8 9240

270

300

330

360

390

63Ga T1/2 = 32.4 sMea

n tim

e of

flig

ht /

μs

Excitation frequency νRF - 1445125 / Hzfrf


ISOLDEbeam (DC)

HV platform

RFQ structure

MCP 5

precisionPenningtrap

coolingPenningtrap

carbon clusterion source

2.8-keV ionbunches

laser beam

MCP 3

MCP 1

60 keV

stable alkaliion referencesource

C60 pellet

80

100

120

140

160

180

200

220 32ArM

ean

TOF

(μs)

νRF − 2842679 (Hz)-40 -30 -20 -10 0 10 20 30

F. Herfurth, et al., NIM A 469, 264 (2001)K. Blaum et al., NIM B 204, 478 (2003)

cluster ion source

preparation Penning trap

precision Penning trap

stable alkali ionreference source

ion beam cooler and buncher

removal of contaminant ions

(R = 105)

determination of cyclotron frequency

(R = 107)

B = 4.7 T

B = 5.9 T

Nd:YAG 532 nm

1.2

m

10 cm10 cm

Triple-trap mass spectrometer ISOLTRAP

8 m

8 m


Resolution and isolation of nuclear isomers

1+

6-

1+

240

270

300

330

360

390

240

270

300

330

360

390

260

280

300

320

340

360

380

400

mea

n TO

F (u

s)

fexc - 1338940 (Hz)0 5 10 15 20 25 30 35

6-

Isomerism in 68Cu: as producedby ISOLDE

isolation of the 1+ ground state

isolation of the 6- isomeric state

Preparation of an isomerically pure beamClear state-to-mass assignmentsTrap-assisted decay and laser spectroscopy

0+

1+

721.6 keV6-

g: T1/2 = 31.1 sm:T1/2 = 3.75 min

IT 84%

16%

100%68Cu

68Zn

K. Blaum et al., Europhys. Lett. 67, 586 (2004)

Applications


Applications: Nucleosynthesis studiesK. Blaum et al., Phys. J. 5, 35 (2006); H. Schatz et al., Europhys. News 37, 16 (2006)

M. Mukherjee et al., Phys. Rev. Lett. 93, 150801 (2004) D. Rodríguez et al., Phys. Rev. Lett. 93, 161104 (2004)

Questions addressed:

• Why is iron so muchabundant than heavierelements such as gold?

• Why are there heavy elements at all and how did they come into existence?

• How can we explain theisotopic composition in the Universe?


Determination of Determination of thethe 7676Ge Ge ββ--DecayDecay QQ--ValueValue

?)2(27634

7632 eveSeGe ++→ −

Question: Is there a ν-less double β-decay?

Reaction:

Mass determination of 76Ge and 76Se

0 22 23-30

-20

-10

0

10

20

76Ge

Mea

sure

d de

viat

ion

[ppb

]

Ion charge state

0 22 23

-30

-20

-10

0

10

20

0 24 25-30

-20

-10

0

10

20

76SeM

easu

red

devi

atio

n [p

pb]

Ion charge state

0 24 25

-30

-20

-10

0

10

20

Q-value of 76Ge (0vββ) :

1 2 32038.0

2038.5

2039.0

2039.5

2040.0

2040.5

2041.0

2041.5

Q-v

alue

Measurement number

7-fold improvement of the Q-value (δm/m = 1 10-9)G. Douysset et al., Phys. Rev. Lett. 86 (2001) 4259.H.V. Klapdor-Kleingrothhaus et al., Mod. Phys. Lett. A 16 (2001) 2409.Performed at SMILETRAP (Stockholm)


Isobaric Multiplet Mass Equation

Tz -3/2 -1/2 1/2 3/2

Me

T=1/2T=1/2

T=3/2 T=3/2T=3/2

T=3/2

33Ar 33Cl 33S 33P

M = a + bTz + cTz2

Commonly usedquadratic form ?

+ dTz3

A = 33, T = 3/2 quartet:

Mass formula for multiplets of nuclear states with same mass and isospin


Most stringent test of IMME (with 32,33Ar)

0 10 20 30 40 50 60-60

-40

-20

0

20

40

60

A

1

-10

Ground state quartets Excited state quartets Ground state quintets

d/

keV

A = 33, T = 3/2 quartet:A = 32, T = 2 quintet:

d = -0.13(45) keVd = -0.11(30) keV

ISOLTRAP measurements 2003:– 33Ar with u (m ) = 0.44 keV– 32Ar with u (m ) = 1.8 keV

New status:K. B. et al., Phys. Rev. Lett. 91, 260801 (2003).


Recent results of fundamental studies

Population inversion of nuclear states andnuclear structure studies:

J. Van Roosbroeck et al., Phys. Rev. Lett. 92, 1112501 (2004)K. Blaum et al., Europhys. Lett. 67, 586 (2004)Sz. Nagy et al., Phys. Rev. Lett. 96, 163004 (2006)C. Rauth et al., Phys. Rev. Lett., submitted (2007)

Why are there elements heavier than iron?D. Rodríguez et al., Phys. Rev. Lett. 93, 161104 (2004)M. Mukherjee et al., Phys. Rev. Lett. 93, 150801 (2004)

Are there scalar currents present in the Weak Interaction?F. Herfurth et al., Phys. Rev. Lett. 87, 142501 (2001) K. Blaum et al., Phys. Rev. Lett. 91, 260801 (2003)

Vud – is unitarity violated in quark mixing?F. Herfurth et al., Eur. Phys. J. A 15, 17 (2002)A. Kellerbauer et al., Phys. Rev. Lett. 93, 072502 (2004)M. Mukherjee et al., Phys. Rev. Lett. 93, 150801 (2004)S. George et al. Phys. Rev. Lett. 98, 162501 (2007)

See talk by J. Hardy and I. Towner tomorrow

d's'b'

dsb

Vud

Vcd

Vtd

Vus Vub

VcbVcs

VtbVts

= ·

1+

6-

260

280

300

320

340

360

380

400

νexc – 1338940 (Hz)

Mea

ntim

e of

flig

ht(μ

s)

1+

6-

260

280

300

320

340

360

380

400

νexc – 1338940 (Hz)

Mea

ntim

e of

flig

ht(μ

s)

www.quantum.physik.uni-mainz.de/mats

Future perspectivesWe want to perform mass measurements on rarely produced heavynuclides. (~1 particle per minute)

Need for

Nucleus Win, NUBASE Data

Cf

Bk

Cm

Am

Pu

Np

U

a non-destructive detection technique

single-particle sensitivity

a low-noise and cold environment


Non-destructive ion detection

x

y

Pickup-Electrode

Pickup-Electrode

ion current signal

Current

time

C. Weber, PhD thesis, University of Heidelberg (2004) and C. Weber et al., Eur. Phys. J A 25, 65 (2005)

Applications

– Mass measurements on heavy/superheavy rare elements– Fast identification and effective use of stored ions

Operation of traps and electronics at cryogenic (4 K) temperature.

„FT-ICR“ Fourier-Transform-Ion Cyclotron Resonance

f p

mass/frequency spectrum

Amplitude

frequency

very smallsignal ~fA

Amplification

Transformation


Status FT-ICR mass spectrometry• traps assembled• 4K reached

• electronic testet• ion traping in progress

R. Ferrer and J. Ketelaer, PhD Thesis, University of Mainz, in preparation (2007)

Precision Penning trap

Cryogenic electronics

9 cm

Single ion sensitivity (singly charged heavy ion)!

www.quantum.physik.uni-mainz.de/mats

SpectroscopySpectroscopy setupsetup at at thethe Mainz TRIGA Mainz TRIGA reactorreactor

ion source

dipole massseparator

collinear laser beam line

Penning trap

laser table

TRIGAreactor

ion source

dipole massseparator

collinear laser beam line

Penning trap

laser table

TRIGAreactor

mass spectrometryandcollinear laser spectroscopyon transuranium elements(Np-Cf) and neutron-rich nuclides

B

In Collaboration with:Klaus Eberhardt Gabriele HampelNorbert Trautmann

Laser spectroscopyteam:Christopher GeppertJörg KrämerWilfried Nörtershäuser

and GSI Darmstadt


Laser and Laser and massmass spectroscopyspectroscopy at FAIRat FAIR

2007 2008 2009 2010 2011 2012 2013 2014 2015

MATS

LaSpec

RFQ

dipole

ions

atoms

gas catcher

ions from Super-FRS


Part II

High-precisiong-factor measurements


The g – factor

relation between magnetic dipole moment and angular

momentum

free lepton: gs = g-factor of the spin


Measurement principle for a proton

precisiontrap

analysistrapelectric potential

magnetic field lines

precisiontrap



precisiontrap



Eigenmotions of the particle cyclotron frequency

Bme

pc =ω

We aim for δg/g < 10-9.

Zeeman splitting in the spin eigenstates Larmor frequency

BmegB

ppL 2

2=

⋅=

h

μω

Lωh

c

Lpg

ωω

⋅= 2


magnetic moment (g - 2)

(g - 2)

q/m

charge/mass

mass difference

10-610-910-1210-1510-18

1s–2s two-photon spectroscopy

rel. precision

e+ e-

μ+ μ-

e+ e-

H H

K0 K0

p p

Test of CPT invariance– Currently believed to hold– CPT transforms particle into its

antiparticle (P. Dirac 1928)

ωc: cyclotron frequencyωL: Larmor frequency

c

Lpg

ωω

⋅= 2

PDG: gp = 2×2.792847337(29) gp = 2×2.800(8)

With our double Penning-trap technique we aim for δg/g = 10-9.

1s-2s two-photon spectroscopy

gg--factorfactor of of thethe protonproton and and thethe antiprotonantiproton


Hybrid analysis trap

1 cm ± 1 μmManufactured at the

Institute for MicrotechniqueMainz (IMM).

J. Verdú et al., AIP Conference Proceedings 796, 260-265 (2005)

Status of the (anti)proton g-factor experiment


- Unitarity test of the CKM matrix:δm/m<10-8 for short-lived radionuclides

- Test of E=mc2: δm/m<10-10 for 32S, 33S

- Test of CPT invariance: δg/g<10-9 for proton and antiproton

- Test of bound-state QEDδg/g<10-9 for hydrogen-like highly-charged ions

- Determination of fundamental constants:me, mp, α, Nah, μ, …

Penning traps are ideal tools to perform high-precision experiments for fundamental studies!

Summary

Email: [email protected] www.quantum.physik.uni-mainz.de/en/mats

Thanks a lot for your attention.


The Helmholtz-Research-Group MATS

In collaboration with: H.-J. Kluge, H. Kracke, M. Kretzschmar, W. Quint, L. Schweikhard, S. Stahl, J. Walz, G. Werth

and the ISOLTRAP team

„Mass“-Team

„g-Factor“-Team

M. Dworschak (PhD), G. Eitel (Dipl.), R. Ferrer (PhD), S. George (PhD), J. Ketelaer (PhD), S. Nagy (PostDoc), D. Neidherr (PhD), J. Repp (Dipl.), Ch. Smorra (Dipl.) S. Kreim (PhD), C. Rodegheri (PhD), S. Sturm (PhD), B. Schabinger (PhD), S. Ulmer (PhD), A. Wagner (Dipl.)

contentm(28si)= 27.976 926 532 6 u δm = 0.000 000 001 9 u rel. precision = 6x10-11 distance...

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