2008/3/19 1

Intensity monitor for GARIS

D. KajiNishina Center for Accelerator Based Science, RIKEN

2008/3/19 2

Contents

1.1. SHE study by GARISSHE study by GARIS

2.2. Irradiation monitorIrradiation monitorPhase probePhase probeCCD cameraCCD camera

3.3. Intensity monitorIntensity monitorPINPIN--diodediodeGas scintillation measurementGas scintillation measurement

4.4. SummarySummary

2008/3/19 3

1. SHE study @ RIKEN

2008/3/19 4

Proton drip lin

e

Neutron number

Prot

on n

umbe

r

Rf

Ds

Mt

Hs

Bh

Sg

Db

112

113

114

115

116

117

118

119

120

Rg

176

175170165160155150145140135130

Cm

No

Md

Fm

Es

Cf

Bk

Lr

Pu

Np

U

Pa

Th

Am

Decay modeDecay modeα SF EC

SHE study by GARISSHE study by GARIS(From 2001 to 2008 year)(From 2001 to 2008 year)

2002-2003, 14atoms208Pb(64Ni,n)271Ds

2002, 10atoms208Pb(58Fe,n)265Hs

2003, 14atoms209Bi(64Ni,n)272Rg

2004, 2atoms208Pb(70Zn,n)277112

2003-2008, 2atoms209Bi(70Zn,n)278113

1

2002197Au(40Ar,3n)234Bk

3

2006238U(22Ne,5n)255No

2007238U(26Mg,5n)259Rf 2

11

3322

Cold fusion studyHot fusion study for SHE chemistryNew neutron deficient actinide isotope search

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Apparatus for SHE synthesis

1 Accelerator to provide intense heavy-ion beam

2 Target to stand against heavy-ion bombardment

Apparatus for SHE identification

3 Separator with good separation and high efficiency

4 Detector to identify with one atom

Backgroundparticles

Reactionproducts

Experimental method for SHE study

4 4 DetectorDetector1 1 AcceleratorAccelerator

Heavy-ionbombardment

2 2 TargetTarget 3 3 SSeparatoreparator

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D1D1 Q1Q1 Q2Q2 D2D2

Target

Beam envelope of reaction product

Projectile

Detectionsystem

HeHe gas gas

VacuumVacuum

GARIS(GAs-filled Recoil Ion Separator)

Characteristics of GARIS

0.97 cm/%

12.2 msr

-1.99

-0.76

Gas pressure

Filled gas

Max. Bρ

Total path length 5.76 mMagnification (X)

2.16 TmMagnification (Y)

HeAcceptance

30～80 PaDispersion

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Detectionsystem

Projectile

D1D2 Q2 Q1

GARIS (GAs-filled Recoil Ion Separator)

Target

Reactionproducts

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Monitor around GARIS

SHE detection monitor(Decay energy & time)

Irradiation monitor1

33/18(TUE) 9:30 Morimoto’s talk

Intensity monitor2

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Yield estimation Yield estimation Yield estimation

100 105 110 11510-2

10-1

100

101

102

103

104

105

106

107

Atomic number

Cro

ss s

ect

ion

[p

b]

48Ca

50Ti

54Cr

58Fe64Ni

70Zn

S. Hofmann, Rep. Prog. Phys. 61, 639(1998).S. Hofmann, private communication.

208Pb,209Bi(HI,n)反応における反応断面積の系統性

: 0.1 pb (10-37 cm2)

: 450 μg/cm2 of 209Bi

(1.2x1018 atoms/cm2)

: 0.5 pμA (3x1012 ions/s)

: 0.8

= Nｘσｘφｘε

= 2.8 x 10-7/s = 1 / 40 day

Yield/s

Cross Section σ

Target Thickness N

Beam intensity φ

Efficiency ε

1pb

0.1pb

長期間にわたる実験条件の

安定性が必要不可欠

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2. Irradiation monitor

Phase probeCCD camera

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Beam energy monitor1 Bρ measurement of 90°bending magnet2 TOF measurement by phase probe

GARIS

Up-grade RILAC

18GHzECR-IS

RFQ LINAC

RILAC(RIKEN Heavy-ion linear accelerator)

L=4.004m

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Energy measurement by phase probeEnergy measurement by phase probe

Projectile

E = 0.15%

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10210-2 10110010-1 Vacuum [Pa]

Top view

Projectile

MBP140 l/s

MBP280 l/s

TMP150 l/s

TMP280 l/s

Side view

GARISTargetchamber

DifferentialPumping

Beam line

Gas-cooled rotating target

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16Number of target frame

7.85 cm2Target area

76%Duty cycle

3000 rpmRotating speed

30.0 cm

Parameters of target system

Diameter of wheel

Target chamber, rotating wheel, and sector target frame

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CCD #3CCD #3

CCD #3CCD #3

CCD #1CCD #1

CCD #1CCD #1

CCD #1CCD #1

CCD #2CCD #2

CCD #2CCD #2

CCD #2CCD #2

CCD #4CCD #4

CCD #4CCD #4

CCD #4CCD #4

Top view Side viewSide view

Irradiation monitor by CCD camera

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Irradiation monitor by CCD camera

CCD cameraMTV-34K0N(秋月電子通商, Japan)¥7,800

11

3322

Irradiation monitorStatus monitor of TargetStability monitor of Accelerator & Ion source

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3. Intensity monitor

PIN diodeGas scintillation measurement

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Intensity monitor by PIN-diode

Top view

Projectile 4545°°

1.41.41515

mm

CurrentMonitor

3.6 x 3.6 mm2

Ω=6.47x10-6sr

Pulse height [chn]

Co

un

ts p

er

chn

.

0

50

0 1000 2000 3000 4000

PIN-photo diodeS1223(Hamamatsu, inc, Japan)¥1,500

Elastically scattered particles from the target at 45°forward angle

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Status of the target

Pulse height [chn]

Co

un

ts p

er

chn

.

0

50

0 1000 2000 3000 40000

50

Initial state

Present state

The number of scattered particles [x109]

I [p

uA

]FP

D/

Ela

stic

FW

HM

[ch

n]

PH

[ch

n]

0

0.5

1

0

0.5

0

50

0 1 2 3 4

2500

ビーム強度

FPDへ異常な入射がある？

標的の均一性

PIN diodeの劣化

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D1D1 Q1Q1 Q2Q2 D2D2

Gas scintillation

Inside view of GARIS

Gas scintillation along beam trajectory

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Projectilefrom RILAC

Monochomater Photo-multiplier

ACRYLITE R

PC (WinXP OS)

Currentmeter

0.5 m

Fiber optics4.0 m

with GPIB-USBinterface

Gas-filled regionof the GARIS

High voltagesupplyTo D2 magnet

of the GARIS

Measurement of gas scintillationMeasurement of gas scintillation

400 500 600 7000

50

100

Wave length [nm]Inte

nsi

ty [

arb

. u

nit

]

Keithley PicoammeterModel 6485

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1s2

s-1

s3p

1

s2p

-1s4

d

1s2

p-1

s4d

1s2

p-1

s4s

1s2

p-1

s4d

1s2

s-1

s3p

1s2

p-1

s3d

1s2

p-1

s3d

1s2

p-1

s3s

1s2

p-1

s3s

Intensity distribution

400 500 600 7000

50

100

Wave length [nm]

Inte

nsi

ty [

arb

. u

nit

]

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0.50 0.50 puApuA

0.17 0.17 puApuA0.05 0.05 puApuA

0.90 0.90 puApuA

Very rough intensity monitorVery rough intensity monitor

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Application as intensity monitor

400 500 600 7000

50

100

Wave length [nm]

Inte

nsi

ty [

arb

. u

nit

]

2008/3/19 25

10-3 10-2 10-1 100 10110-3

10-2

10-1

100

101

Beam intensity [pμA]

Emiss

ion

stre

ngth

[arb

. uni

t]

Scintillation/Elastic ratio

2008/3/19 26

Summary

1.1. GARISGARISによる最近の超重元素探索の現状を紹介した。による最近の超重元素探索の現状を紹介した。

2.2. GARISGARIS実験における照射モニターを紹介した。実験における照射モニターを紹介した。Phase probePhase probeCCD cameraCCD camera

3.3. GARISGARIS実験におけるビーム強度モニターを紹介した。実験におけるビーム強度モニターを紹介した。PINPIN--diodediodeGas scintillation measurementGas scintillation measurement

2008/3/19 27

K. Morita (RIKEN)K. Morita (RIKEN) K. Morimoto (RIKEN)K. Morimoto (RIKEN)

Y.Y.--L. ZhaoL. Zhao ((IHEP)IHEP)E. E. IdeguchiIdeguchi((CNS)CNS)

H. HabaH. Haba ((RIKEN)RIKEN)

((Univ. of Tsukuba)Univ. of Tsukuba)A. OzawaA. Ozawa

((IMP)IMP)H. H. XuXu

T. T. SudaSuda ((RIKEN)RIKEN)

T. YamaguchiT. Yamaguchi ((Saitama Univ.)Saitama Univ.)

S. GotoS. Goto ((Niigata Univ.)Niigata Univ.)

H. KouraH. Koura ((JAERI)JAERI)K. K. SuekiSueki ((Univ. of Tsukuba)Univ. of Tsukuba)

A. YoshidaA. Yoshida ((RIKEN)RIKEN)

((RIKEN)RIKEN)T. OhnishiT. Ohnishi

H. H. KudoKudo ((Niigata Univ.)Niigata Univ.)

A. A. YonedaYoneda ((RIKEN)RIKEN)T. Akiyama (Saitama Univ.)T. Akiyama (Saitama Univ.)

Collaborators

D. D. KajiKaji (RIKEN)(RIKEN)

T. SatoT. Sato ((Tohoku Univ.)Tohoku Univ.)K. K. OzekiOzeki ((RIKEN)RIKEN)