Search for Permanent Electric Dipole Moments of Francium Atom

Yasuhiro SAKEMI Research Center for Nuclear Physics (RCNP)

Osaka University

For EDM CollaborationK.Hatanaka, A.Tamii, S.Morinobu, Y.Shimizu, K.Fujita, Y.Tameshige, H.Matsubara (RCNP)

K.Imai, Y.Takahashi, T.Murakami (Kyoto Univ.)T.Wakasa (Kyushu Univ.), Bhanau P. Das (Indian Institute of Astrophysics)

B-PAC on 21-Feb.-2005

AVF Cyclotron Upgrade Project at RCNP

SC ECR Heavy Ion Source

AVF Cyclotron

Diagnosis Beam Line

EDM search with Laser Trap Apparatus

New Technique = Radioactive Atom Production with Accelerator + Laser Trapusing

New machines constructed in AVF Upgraded Project in 2004/2005

Search for permanent EDM

CPT ~ invariant in quantum field theory : No evidence of violationT: Time Reversal ~ No evidence of violation CP: violation was found ~ K0, B decayCPT theorem + CP violation → T violation ?

Window to look at Beyond the Standard Model

Time Reversal Symmetry ~ Violation ? ~ Test !

+-

+-

Td

s

Electron EDM

dn=Δu・du+Δd・dd+Δs・ds

Electric Dipole Moment

if EDM is observed ~ Beyond the Standard Modelif EDM is measured ~ signal of supersymmetry~ mechanism of SUSY violation

Best current limit EDM : |de|<1.5×10-27 e・cm from E.D.Commins et al (California), 205Tl

A challenge is set !

de < 10-28 e・cm

EDM and MSSM

2

sin~

Mµθ

Electron EDM in MSSM → limit to CP-violating phase in MSSM

EDM Measurement and Sensitivity

TNEKehd

⋅⋅⋅⋅⋅=

τδ 111

2

EdhEdBhEdBh

⋅=∆⇒

⋅−⋅=

⋅+⋅=

↑↓

↑↑

42222

νµνµν

E E

Sensitivity :

K: Enhancement factor ~ Atom EDM = Largest ~ FranciumE : Electric Field ~ Strong, 100 kV/cm = Laser trap in high vacuumN : Number of Particles ~ Many particles ! = Ion Source + Ion guideτ: Coherence Time (Stored time) ~ Long ! = Laser trapT : Lifetime of Experimentalist ~ Long !

Electric dipole moment : d

20

252

23

)0(~

~

aeVZ

Zd

d

s

e

atom

αψ

α

∑

∑∑∑

∑

⋅−+

⎥⎦

⎤⎢⎣

⎡∇⋅+⎥

⎦

⎤⎢⎣

⎡∇⋅=

−=

≠

iiiie

kjjk

iii

e

iii

e

iiiie

Ed

BedH

ed

EdH

σβ

σσ

σβ

)1(

21,,

'

0

Enhancement factor

0

200

400

600

800

1000

1200

1400

0 20 40 60 80 100

K

Charge : Z

Enhancement factor simple

RbXe Cs

Tl

Fr

Enha

ncem

ent f

acto

r

Charge :Z

Enhancement effects for Atomic EDM

Heaviest Alkali Atom : Francium 210Fr ~ K=1150

1939 found Atomic number 87 Average atomic weight 215 Ionization Potential 4.08 eVRadioactive lifetime of Fr210 =3.2 minNo stable isotopes ~ longest lifetime 223Fr: 22min.

Relativistic effect

Present status

MOT+Laser Trap

MOT+Laser Trap

Atomic beamMOTMOT/PenningMOTTrap

171Yb (p) KyotoXe (p)T.I.T.

TISOLTRIUMF~10-27Best limit 205Tl (e)California / LBL

~10-28This proposal210-212FrRCNP

First beam Ra (p)TRIuPKVIAtomic structure210FrSUNY

Goal Status Elements ProjectInstitute

Dy,Sm,BaFr

Yb

205TlRa

129Xe 3P2

Others199HgRn129Xe 1S0Nucleus OthersFe3+CsRbElectron

Elements EDM

Experimental Overview

Au targetY neutralizer

Ion transport lenses

18O beam from AVF cyclotron

Cell

Trapped Francium

Chip for Magnetic Trap

Laser Beam

Fr+ ion

Francium Production with Heavy Ion Fusion Reaction :

197Au(18O,xn)209-211Fr

Advantage

Atom Production(Francium)

Atom Trap(Laser Trap)

TNEKehd

⋅⋅⋅⋅⋅=

τδ 111

2

~10-3 s~101410 kV/cm585205Tl(atomic beam)~102 s~108100 kV/cm1150210Fr(trap)

Coherence timeAtom numberElectric fieldEnhancement factorτNEK

No systematic influence of motional magnetic field ~ v×E effect

This proposal

Francium production

Fusion Reaction : 18/16O + 197Au → 207-211Fr + Xn

Francium desorbs from the target surface as atoms/ions according to

⎟⎠⎞

⎜⎝⎛ −

=+

kTEE

nn IPWFexp

21

0

Target : Gold (Au) ~ EWF(5.1eV)>EIP(4.1eV) → Fr+ ionTarget : Yttrium (Y) ~ EWF(3.1eV)<EIP(4.1eV) → Fr atom

18O beam from AVF

Au target Y targetFr+ ion

Fr atom

To Trap/Cooling

Fr/sec

0

50000

100000

150000

18O Beam Energy (MeV)70 80 90 100 110 120

Francium intensities @ 0.1 uA at SUNY

210/211Fr

208/209Fr

Surface Ionization Efficiency

⎟⎠⎞

⎜⎝⎛ −

+=

+ kTEE WFIPexp1

10

ωω

ε

Ion production efficiency ~ from Langmuir-Saha equation:

Ionization efficicency

0.85

0.9

0.95

1

1.05

74 76 78 80 82 84

Target element number

efficiency

efficicency

Re Os Ir Pt Au Hg Tl Pb Bi

Melting point ~ highWork function ~ high

•EIP(Fr)=3.83 eV•EWF(Au)=5.1 eV•EWF(Pt)=5.65 eV

Fusion reaction cross section

210Fr ~ t1/2= 3.18 min. / limit = 370 kBq/day, 4.44 MBq/year211Fr ~ t1/2= 3.08 min. / limit = 370 kBq/day, 4.44 MBq/year212Fr ~ t1/2= 19.3 min. / limit = 20 kBq/day, 0.24 MBq/year

11B+208Pb Fr production

0.01

0.1

1

10

100

1000

50 70 90 110 130

beam energy (MeV)

Cross section (mb)

216Fr 215Fr 214Fr 213Fr 212Fr 211Fr

210Fr 209Fr

18O+197Au Fr production

0.01

0.1

1

10

100

1000

50 70 90 110 130

beam energy (MeV)

Cross section (mb)

212Fr 211Fr 210Fr 209Fr 208Fr

11B+208Pb 18O+197Au19F+198Pt Fr production

0.01

0.1

1

10

100

1000

50 70 90 110 130

Beam Energy

Cross Section (mB)

212Fr 211Fr 210Fr

19F+198Pt

Best choice ~ 19F ~ 212Fr : 19F beam …Better choice ~ 18O ~ 210Fr : 197Au ionizer ~ low melting point

18O+197Au

Fr

Rn

At

Po

Bi

209 210 211

206 207 208

209 210

207 208

204 205 206

Ionization Potential

(eV)

3.83

10.748

9.65

8.43

7.289

19F+198Pt

Fr

Rn

At

Po

Bi

211 212 213

211 212 213

208 209 210

206 207

208

1 4 7

10

13

16

19

22

25

28

31 n

1

10

100

1000

10000

event(arb. unit)

energy (MeV)

particle

emitted particles

n p alpha gamma

Background

Neutron ~ a few MeV→ damage to detector (CCD chip) to diagnose the accumulated atoms→ Laser trap equipments ~ should be located far from production target

MC~5000 events generated

Beam intensity from ECR ion source

6 pμA

1.1 pμ A

18O beam intensity ~ Information from Dr. Nakagawa at RIKEN

Plasma electrode hole diameter 10mm

•6+ > 500μA ~ 1 mA (>80pμA)•7+ > 200μA (>30pμA)•8+ > 50μA (>6pμA)

Normalized emmitance(covering 99% beam intensity)•1~2mA 0.1πm mrad•~5mA 0.3~0.4πm mrad

evaluated by Dr.Ninomiya

Ring Cyclotron

New Beam Line

Beam Line

Electrostatic Lenses

Laser Trap

Required to construct

~ 12 m

①②

③④⑤

Surface Ionizer

Beam dump

Beam diagnosis

Beam emittance

This Proposal

Beam Optics

18O beam from AVF

Fr production target •Focus point •Beam size tuning ~ possible •Surface ionizer locate

Optics ~ designed by Transport/Gios

Laser Trap

Concrete shield

Fr+ ion beam Electrostatic lenses

Fr ion guide •Small emittance ~ surface ionizer electrode •Electrostatic lenses ~ transport all Fr isotopes•Transmission ~ surface ionizer and beam line design

Production efficiencies

0.10.60.90.40.99Efficiency

4.28E+044.28E+057.13E+057.92E+051.98E+062.00E+060.2 puAIntensity

SUNY

0.210.60.950.60.990.1Efficiency

1.21E+075.76E+079.60E+071.01E+081.684E+081.701E+085.5 puA19F 55 puAIntensity

Phase3

0.030.60.950.60.990.1Efficiency

2.00E+061.73E+065.76E+079.60E+071.01E+081.684E+081.701E+085.5 puA19F 55 puAIntensity

GoalPhase2

0.030.60.950.60.99radiation limitEfficiency

6.09E+052.03E+073.38E+073.56E+075.94E+075.998E+076 puA18O 100 puAIntensity

Phase1

0.030.60.90.30.99radiation limitEfficiency

2.89E+059.62E+061.60E+071.78E+075.94E+075.998E+076 puA18O 100 puAIntensity

Exsiting technique

laser coolingextractionvacuumtransmissionextractionionizationFr productiontransmissionion sourceEfficiency

GoalMOTNeutralizerIon guide Surface IonizerTargetBeam lineAVFECREquioments

ECRIon source Accelerator Beam line Surface

Ionizer Ion guide Neutralizer MOTCell

Y(Atom in MOT/s)=Y0(produed in fusion reactoin)×εion・εext・εtrans・εvac・εneu・εMOT

Fr EDM search strategyExisting technique

Extraction efficiency ~ high

Max beam intensity ~ radiation protection…

19F+198Pt ~ ion source… 19F beam

19F+198Pt~ high extraction efficiency

Max beam intensity of 19F~ radiation protection

19F+198Pt~high trap efficiency

SUNY

accyracy

1.0E-29

1.0E-28

1.0E-27

1.0E-26

1.0E-25

0 5 10 15 20 25 30 35

measurement time (days)

EDM accuract (e cm)

210Fr 210Fr+high extraction210Fr+high intensity 212Fr212Fr+high extraction 212Fr+high intensity

SUSYLarge CP phase

SUSYSmall CP phase

Current limit ~ 205Tl 5yeras data

SUNY

Phase1 ~surface ionizer

Phase2 ~ion source

Phase3 ~MOT

Goal

•Surface Ionizer ~ high extraction efficiency •Ion Guide ~ high transmission efficiency•19F beam ~ ion source•Trap efficiency ~ MOT design

19F beam possibility

Beam intensity

0

20

40

60

80

100

120

140

160

180

4 5 6 7 8 9

charge

Current (puA)

18GHz ECR 18O 18GHz ECR 19F (estimated)

10GHz ECR 18O 10GHz ECR 19F

Information from Dr.Nakagawa

10GHz ECR ion source at RIKEN19F ~ tested by Hatanaka-san

Used gas ~ CHF3

Beam intensity ~ up to radiation protection limit (6puA)

want to challenge to obtain high intensity 19F beam → decision by Accelerator group

Trap Apparatus

Au targetY neutralizer

Ion transport lenses

18O beam from AVF cyclotron

Cell

Trapped Francium

Chip for Magnetic Trap

Laser Beam

Fr+ ion

MOT Trap efficiency ~ depends on 1. Beam diameter of trap laser → beam expand2. Fr : alkali atom ~ sticky → dry film coating inside cell3. Vacuum → high vacuum

Beam expand

Surface ionizer design Surface ionizer at SYNY

30 mg/cm2

Fr production

100 mg/cm2 ~50 um

•Focus elements ~ design•Beam emittance ~ small

18O Beam

Beam time schedule1. Ion guide test with 18O(197Au,xn)Fr reaction ~ 1 day

~ basic test 2. Check the number of produced Fr ions and beam transport optimization ~ 2 days

~ surface ionizer efficiency, transmission efficiency 3. Measurement of Fr atoms extracted from neutralizer ~ 2 days

~ extraction efficiency of neutralizer

TOTAL ~ 5 days beam time

Ion Guide with electrostatic lenses

Surface Ionizer

18O beam from AVF

Fr+ ion

1. FC

2. CatcherProduced atom

3. NeutralizerExtracted atom

2 days 2 days1 day

Required budget

¥80,300,000総計

¥3,800,0005 合計

GND外部資金・共同利用¥3,000,000computer, electronicsDAQ system205

浜松外部資金・共同利用¥300,000photon detector 195

外部資金・共同利用¥200,000silicon detector185

SONY外部資金・共同利用¥300,000CCD cameradetector175

¥5,300,0004 合計

外部資金¥2,000,000ion pump etc..Vacuum164

Keopsys科研費（萌芽）申請中¥3,000,000fiber laser trap laser 154

ホリゾン科研費（萌芽）申請中¥300,000chamber science chamberLaser Trap144

¥55,500,0003 合計

メレスグリオ外部資金¥3,000,000mirror, beam expander, bread board …optical elements133

CoherentCollabolation、外部資金¥50,000,000Ti-sapphire lasertrap laser 123

タカノ技研外部資金¥500,000coil for MOTcoil 113

ホリゾン外部資金¥2,000,000chamber vacuum chamberMOT103

¥11,000,0002 合計

Project apply¥3,000,000ocntrol/interlock92

Project apply¥2,000,000vacuum system82

Project apply¥1,000,000shield72

Project apply¥5,000,000rotary shutterbeam line extension62

¥4,700,0001 合計

This proposal¥150,000silicon detectordetector51

This proposal¥1,000,000pumpVacuum system41

高砂This proposal¥400,000Power supply and controlPower supply31

KTサイエンスThis proposal¥2,400,000electrostatic lenses, beam pipe, support frameFr beam line 21

日本VacsメタルThis proposal¥750,000W rod, extraction electrode, heaterSurface ionizerFr production11

contactbudgetcostcontentsEquipmentsFunction00