Search for Permanent Electric Dipole Moments of Francium Atom

Yasuhiro SAKEMI Research Center for Nuclear Physics (RCNP), Osaka University

For EDM collaboration

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

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

Overview of beam line for EDM search experiment

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

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

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)

ED

M a

ccura

ct

(e c

m)

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

2007/LHC start, 2009/LHC high luminosity

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

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

Char

ge :

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

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

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

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

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

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

eff

icie

ncy

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)

Cro

ss s

ecti

on (

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)

Cro

ss s

ecti

on (

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

Cro

ss S

ection (

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

19F beam possibility

Beam intensity

0

20

40

60

80

100

120

140

160

180

4 5 6 7 8 9

charge

Cu

rre

nt

(pu

A)

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

分析ビームラインの現状

分析ビームラインの機能1. ビーム診断：AVFからのビームを診断し、高分解能ビーム調整時に活用。

2. ビーム伝送：中性子、西、東 各実験室にビームを伝送する。3. EDM探索実験のためのフランシウム生成用ビームライン。（検討中）

分析ビームライン（AVF Beam Analyzer）

Optics: Dispersive Mode ~ Dispersion 12.6m

真空箱A-1BV-Inj2a:ビューアーDG:ディグレーダー

真空箱A-2BV3:ビューアー

真空箱A-3BV6: ビューアーTPM7: ３線式プロファイルモニターESH7/ESV7: 固定幅スリット 真空箱B

BV2-a:ビューアーBV2-b:ビューアー

真空箱CTPM8: ３線式プロファイルモニターGEM: ガス電子増幅検出器

真空箱DBS7: ビームストッパー

真空箱EＢＶ8: ビューアー

VS3: 真空排気セット

VS7: 真空排気セット

四極磁石QA-2

四極磁石QA-1

四極磁石QA-3

四極磁石QA-5

四極磁石QA-4

四極磁石QA-6

四極磁石 QA-7U

四極磁石 QA-7D

四極磁石 QA-8U四極磁石 QA-8D

偏向電磁石BA-1偏向電磁石

BA-2

偏向電磁石BA-3

焦点面（ＢＶ６，ＴＰＭ７）

焦点面（ビューアー：ＢＶ６，3線式モニタ：ＴＰＭ７）

分析ビームライン全景

表面イオン化器設置候補場所

偏向電磁石（BA1/2/3)設計方針

Geometricalな情報はすべてIncludeしたモデル

1. シム形状2. ロゴスキー3. フィールドクランプ

決定パラメータ

BA1/31. 磁極曲率：フラット2. FC折り返し：151.0mm

BA21. 磁極曲率：上流 746.6mm2. FC折り返し：上流 175.5mm3. 下流はFC1/3と同じ

1. 偏向電磁石の磁場分布計算（シム形状等はすでに決定済み）。（TOSCA）2. 磁場Inhomogenetyの情報を、Opticsにとりいれて計算。（Optics）3. Focal Planeの傾きが入射軸に対して直角になるように磁極端面の曲率を決定。(Optics)4. 必要な磁極曲率を実現するように、磁極・フィールドクランプの（実際の）曲率を決定。(TOSCA)

TOSCAによる3次元モデル計算

シム形状

1. 磁極幅 ：300 mm2. 端面曲率

BA1（上流偏向磁石）出口 ：1882.7 mm ⇒2036.1 mmBA2（下流偏向磁石）入口 ： 541.6 mm ⇒ 679.5 mm

3. 端面角度 ：角度つけない。

4. シム形状位置

内側シム ：磁極中心から１１２mmの位置よりシムをつける。外側シム ：磁極中心から１１１mmの位置よりシムをつける。

厚さ ： 1 mmC面サイズ ：18 mm

150 mmX mm

1 mm18 mm

18 mm磁極中心

磁場均一度：磁石位置依存性（TOSCA）

５度：磁極端面に近づくと①一様な領域は狭くなる。

⇒ただし、ビームの広がりは磁石中央付近で最大となり、端面では小さいので、許容範囲。

②磁場中心は磁極中心に近づく。

この位置依存性を考慮し、磁極端面の曲率を修正：

①双極磁石を５つの領域に分割。（端面部：0-10度/10-22.5/中央部：22.5-67.5/67.5-80/端面部：80-90）②磁場inhomogeneity DataをIncludeして、Optics計算。③Focal Planeがまっすぐになるよう、端面曲率を最適化。

...12

0

+

+

−=

Rx

Rxn

BB β

Reg

ion

1Re

gion

2

Region 3

Region 4

Region 5

300 mm

磁場均一度：励磁強度依存性（TOSCA）

1.1 T以下は一様な領域（11cm以上）を確保。1.2 T以上になると、急激に狭くなる。

300 mm

磁場一様性測定結果

0

2000

4000

6000

8000

10000

12000

14000

16000

-400 -300 -200 -100 0 100 200 300 400

B=0.7T B=0.9T B=1.3T

0.999

0.9992

0.9994

0.9996

0.9998

1

1.0002

1.0004

1.0006

1.0008

1.001

-150 -100 -50 0 50 100 150

B=0.7T B=0.9T B=1.3T

R(mm) R(mm)

B(Gauss) B(r)/B(r=0)

•目標とした一様性：±50mmの範囲で10-4を実現。•TOSCAでの計算結果と同じ傾向を示す。～後ページ参照。

•多重極成分等の検討～詳細解析必要。

EFB測定結果

-1000

1000

3000

5000

7000

9000

-300 -200 -100 0 100 200 300 400

x=0 at 0.9T x=-100 x=-50 x=50 x=100

-1000

1000

3000

5000

7000

9000

-300 -200 -100 0 100 200 300 400

x=0 at 0.9T x=-100 x=-50 x=50 x=100

曲率を持った磁極端面 平坦な磁極端面

Ｘ＝０：磁極中心

Optics

Focal Plane

Dispersive Transport Achromatic Transport

Vertical Vertical Horizontal Horizontal

Beam size <120mm

New Beam Line

WS beam Line

Dispersion = 30 m

Target

Transport to WS (High Resolution) Beam Line

ビューアーおよび3線式モニターによるビーム診断

ＡＶＦ：64.63 MeV 陽子ビーム

ビューアー：ＢＶ６ 3線式モニター：ＴＰＭ７

10mm~100keV 10mm

ＡＶＦ新位相スリットによるビーム調整１

ＴＰＭ７～２成分あり

新位相スリット：ＰＯＳ～1成分きる

Before AVF tuning

ＡＶＦ新位相スリットによるビーム調整２

新位相スリット：ＧＡＰ～ビーム幅細くなり、

裾もなくなる

After AVF tuning

分析ビームラインの現状と今後の予定

現状：• Dispersive modeとAchromatic modeのビーム伝送テスト完了。

• 中性子実験室での伝送テスト完了～共同利用実験開始。• ビーム診断テスト～基本的なテストは完了。継続してビーム診断を行う。

今後の予定：• ビームエミッタンスの測定、秋にソフトウエアの作りこみ完了。• 西実験室への伝送テスト～アクロマおよび分散モード。• 重イオンビーム伝送時に、伝送効率の測定を行う。• EDM探索実験へ向けての準備。

表面イオン化器

収束電極：Focusing electrode: Outer diameter ~ 68.7mmHalf-aperture angle ~ 75 deg.

性能：金ターゲット表面での温度を 1200 Kに保つ。1. チェンバー形状：直径100mm×長さ300mm2. 均熱ゾーン寸法：金ターゲット部分：直径8mm、厚さ2mm3. 加熱温度：常用：1200K4. 加熱資料：金ターゲット＋タングステンサポートロッド＋セラミック5. 真空度：10-6 ~ 10-7 Torr6. 使用雰囲気 高真空容器中

セラミックの外枠：電極とタングステンロッドとの絶縁

ターゲット：金直径 ~ 8mm厚さ ~ 2mm

81 mm

Tungsten rod

コイルヒーター

モリブデン熱シールド

タングステンロッド

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

①ターゲット

②ヒーター

③収束電極

④温度モニター

⑤真空排気系

フランシウムイオン

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

Overview of Laser cooling and trapping

2. Surface Ionizer

1. Beam Line

3. Fr transfer line

4. Neutralizer

5. Decelerator 6. MOT

7. Laser Trap

8. EDM detector

?

< 10×δ

~ δ/2

Laser detuning Beam size

~ 10 nKEvaporation cooling

~ 1cm/sDipole force~ uKRecoil limit

>>Is=2.67~ 30 cm/sMOT~ 100 uKDoppler limit

>>Is=2.67~100 cm/sDoppler cooling~ mKOptical cooling

Laser power(mW/cm2)VelocityCoolingKTemperature

Beam collimation laser

Atom cooling laser

Atom trapping laser

Atom transfer laser

Atom trapping laser

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

6. MOT (6)ver1 – Cell design Design principle : 1. Laser beam size (diameter > 20 mm, 30 mm@SUNY) ~ Cell size (diameter/cubic < 30 mm)2. Windows for laser beam ~ 6 for MOT including 1 for Decelerator , 6 for Laser Trap3. Dry film coating4. Material ~ Quartz ~ less metal material for the EDM search 5. Shape ~ Cubic (5 cm, corner ~ 1.5 cm diameter window, glass neck 1.5 cm neck)

cell

trapv V

Vf =

植野氏＠ジャパンセル1. 製作困難：形状の複雑さ2. 8面体、12面体は実績あり

3. 材質：パイレックスあるいは石英4. 表面：ＡＲコーティングの実績5. ガラスからメタルフランジ：アネルバ

1. セル2. オプティカルコンタクト3. バーナー4. パイレックス菅5. 膨張率の違うガラス6. メタルフランジ

6. 内径26ミリは製作中

1

1

2

2 3

3 4

4 5

5

6

6 7

7 8

8 9

9

A

B

C

D

E

F

A

B

C

D

E

F

No. D A T E DESCRIPTION OF CHANGE

日付 DATE第３角法 単位 m m

作成 DRAWN BY検討 CHECKED BY承認 APP'D BY尺度 SCALE 材質 MATERIAL 処理 FINISH

品名 DESCRIPTION

図面番号 DWN NUMBER

株式会社 ジャパンセル

O.UENO

1:2 ﾊﾟｲﾚｯｸｽ

直方体真空ガラスセル

切り欠き位置の指示

接合：オプティカルコンタクト

4面マルチARコート

λ＝400、 650、 770nm θ＝0°

※AOI＝0 設計シミュレーションによる

3C -0692

2004/10/27

-1

2004/11/01 寸法変更（図番-1）

120（有効110）

90

4面マルチARコート 4面マルチARコート

90

5

セル断面A-A'

A A'

φ32

（φ28）

（φ24）

4面マルチARコート4面マルチARコート4面マルチARコート4面マルチARコートICFφ70フランジ

□40□50

Laser cooling and trapping

K

mK

uK

nK

3

300

30

3

300

30

3

300

30

3

300

30

3

Surface of the sun

Laboratory

Resonant collisions

Liquid He

He cryostat

Dilution refrigerator

Optical cooling

Doppler limit

-

Recoil limit

Raman processes

Evaporation cooling –BEC

Sub-kHz bandwidth

Collisions

Radiative

Laser cooling

Evaporation

Decelerator

MOT

Laser Trap

Neutralizer

Goal : Temperature ~ μK

Fusion reaction ~ MeV

Neutralizer

Surface ionizer ~ keV

Cooling ~ uK

4. Neutralizer (3) – Velocity distribution

Oven (Y) temperature : 1000 K~ vapor pressure = 1 Torr~ heater temperature for Fr atom releaseCapturing velocity : Vc~1 m/sFraction of trapping atoms : 10-4 ~ 10-5

Velocity distribution

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0 100 200 300 400 500 600 700 800

Atom velocity (m/s)

frac

tion

210Fr@T=1000K 85Rb@T=568K

vFr~281 m/s, vrms~345 m/s

vRb~333 m/s , vrms~408 m/s

5. Decelerator (1) –Beam deceleration

( )[ ] 2/212/

20

0 γγωδ

γγ ks

skkamFD

p

rhr

hr

hrr

→+++

===

F

Stopping length and time

0.73 0.88 0.94

3.59

5.53 5.43

0

1

2

3

4

5

6

50 100 150 200 250

Atom Mass Number

Lengt

h(m

) / T

ime(m

s)

min stopping length min stopping time

maxmin

max

2

min3

22

3

2

avt

kTk

Mk

MTk

avL B

B

=

===γγ hh

6. MOT (5) – Laser Transport

Type 1 Type 2

Laser wave length 718nm(817nm)@Fr, 780nm(795nm)@RbLaser power >>Is~3 mW/cm2 : SUNY ~ 18 mW/cm2(3 mW/cm2) Line width ~ 1 MHzTuning range > 10γ~ 10 MHz~100 MHz~1 GHz (detuning : 15~25 MHz) Beam size 15 mm ~ 30 mm

MOPA (Master Oscillator Power Amplifier): LD with ECLD +Taper amplifierFor MOT : Calibration

1. 780 nm@Rb D2 line ~ need! ◎ ~100 mW ~ OK? , in future Taper amplifier extension2. 795 nm@Rb D1 line ~ rental

For MOT : EDM search 1. 718 nm@Fr D2 line ~ need! ◎ > 500 mW ~ possible ?2. 817 nm@Fr D1 line ~ need! ◎ > 200 mW ~ sufficient power ?, necessary ?

For Laser TrapFiber laser ~ same as polarized 3He ion source ~ rental

Trapping Efficiency

( )( )[ ]

Laser

cvbounces

cvDnLasercMOTDntrap

vPfN

vPfvPP εεηεεη ⋅−

−−

⋅⋅=⋅⋅⋅=

1

1

1111

)(Goal : Cooled atom number ~ 108 → Trap efficiency : Ptrap~ higher !

ηn Neutralizer efficiency : material, LEDεD Decelerator efficiency : Collimation laserPMOT MOT efficiency : Decelerator

fv trap size : Laser sizeP1(vc) trap efficiency : Laser detuning, powerNbounce Bounce : Coating, LED

εLaser Laser trap efficiency : Laser power

Efficiency with Decelerator

0

0.2

0.4

0.6

0.8

1

1.2

star

t

Neutra

lizer

Decele

rato

r

MO

T Tr

ap Cell

Bounc

e

Lase

r Tra

p

Cooling/Trapping item

Eff

icie

ncy

Efficiency Total efficiency

Efficiency w/o Decelerator

0

0.2

0.4

0.6

0.8

1

1.2st

art

Neutra

lizer

Decele

rato

r

MOT Tra

p

Cell

Bounc

e

Lase

r Tra

p

Cooling/Trapping item

Eff

icie

nc

y

Efficiency Total efficiency

4. Neutralizer (1) – Material

−

=

−

=+

11600)(

)()(exp21exp

21

0 KTeVEeVE

kTEE

nn IPWFIPWF

21254.056.84Zr

17993.16.38Y

3.83210Fr

Comments Melting point(K)Work function(eV)Ionization potential(eV)Atom

atom production efficiency

1000,0.999894969

0.99

0.992

0.994

0.996

0.998

1

1.002

300 500 700 900 1100 1300 1500 1700

Temperature (K)

Eff

icie

ncy

atom production efficiency

Temperature ~ diffuse from the inside materialY, T=1000 K

Boiling point (950K)Melting point (300K)

stopping range

0

5

10

15

20

25

0 2 4 6 8 10 12

Fr ion energy (keV)

range

(A)

stopping range

1 layer

5 layers

4. Neutralizer (2) – Production efficiency

Heater

Material surface

LED1. Fr ion energy ~ embedded depth 2. Fr atom production

(1) Deep region ~ heating (2) Surface region ~ light

3. Neutralizer efficiency ~ rate equation

)()(

TNTN

dtd

τρξ −=

5. Decelerator (2) – Laser requirement

( )[ ] 2/212/

20

0 γγωδ

γγ ks

skkamFD

p

rhr

hr

hrr

→+++

===

1'

1

3 3

0

<<⋅−+−=+

>>=≡

vkB

hcI

IIs

ALD

s

rr

h

µωωωδ

τλπ

Laser power >> Saturation intensity : Is

Detuning ~ position dependence B

> 140 mW2.67Fr

1.09Cs

> 117 mW~ 90 mW~120 mW1.67Rb

Trap@Φ30mmCollimationDecelerationIs (mW/cm2)Atom

5. Decelerator (3) – Zeeman slower

Zeeman slower

0

50

100

150

200

250

300

350

400

0 20 40 60 80 100 120

distance (cm)

Magn

eti

c f

ield

(G

)

Fr-1 Fr-2 Rb-1 Rb-2

( )

Bggee uMgMgkvB

kMvz

zzBzB

)(

1

00

20

0

00

−≡

≡

−=

h

h γη

z0: magnet length ~ minimum stopping length > Lmin

5. Decelerator (5) – Cooled atom distribution

Cooled Fr distribution

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

0 2 4 6 8 10 12 14 16 18 20

Velocity (m/s)

fracti

on

Fr@0.01m/s Fr@0.1m/s Fr@1m/sCapturing velocity ~ 1 m/s

0.66

0.04

0.001

Velocity distribution

0

0.02

0.04

0.06

0.08

0.1

0 100 200 300 400Velocity

Fra

cti

on

Fr@1000K Fr@1K Fr@0.1K Fr@0.01K

Doppler limit : mK ~ 100 uK

7. Laser trap (4) – Trap lifetime

)(10~)(

8

TorrPsTtrap

−

life time

0.001

0.01

0.1

1

10

100

1000

1.E-12 1.E-11 1.E-10 1.E-09 1.E-08 1.E-07 1.E-06 1.E-05 1.E-04

vacuum (Torr)

Life t

ime (

s)

life time

Beam lineFr transfer line

MOTLaser trap

High vacuum

Francium Yield – from production to dump through trapping

Fr yield

0.01

0.1

1

10

100

0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000

Time (msec)

Yeild

(A.U

.)

Fr-yield with efficiency Fr-yield raw

Transport to neutralizer < 1 msCollection time < 30 sAtom decelerator ~ 10 msMOT cooling/dumping ~ 5 msLaser transfer ~ Laser trap and DAQ ~ 60 s

Cooling and Trapping time ~ 20 ms : Atom decelerator (10ms) + MOT damping(5ms)+Laser transfer()

Collection time ~ 30 s

Atom dump

Data Acquisition time ~ 60 s

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

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