2008/3/19 1 Intensity monitor for GARIS D. Kaji Nishina Center for Accelerator Based Science, RIKEN
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
2008/3/19 5
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
2008/3/19 6
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
2008/3/19 7
Detectionsystem
Projectile
D1D2 Q2 Q1
GARIS (GAs-filled Recoil Ion Separator)
Target
Reactionproducts
2008/3/19 8
Monitor around GARIS
SHE detection monitor(Decay energy & time)
Irradiation monitor1
33/18(TUE) 9:30 Morimoto’s talk
Intensity monitor2
2008/3/19 9
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
2008/3/19 10
2. Irradiation monitor
Phase probeCCD camera
2008/3/19 11
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
2008/3/19 12
Energy measurement by phase probeEnergy measurement by phase probe
Projectile
E = 0.15%
2008/3/19 13
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
2008/3/19 14
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
2008/3/19 15
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
2008/3/19 16
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
2008/3/19 17
3. Intensity monitor
PIN diodeGas scintillation measurement
2008/3/19 18
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
2008/3/19 19
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
2008/3/19 20
D1D1 Q1Q1 Q2Q2 D2D2
Gas scintillation
Inside view of GARIS
Gas scintillation along beam trajectory
2008/3/19 21
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
2008/3/19 22
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
]
2008/3/19 23
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
2008/3/19 24
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)