Transcript Progress of AVF cyclotron

A Report to the Advisory Committee of CNS
The Accelerator Group
Upgrade of AVF Cyclotron
•Outline
•Progress in April – December 2006
•Schedule in Jan. 2007 – March 2008
Shigeru Kubono, Yukimitsu Ohshiro, Shin-ichi Watanabe. Syoichi
Yamaka(CNS)
Sergey B. Vorozhtsov, Alexey S. Vorozhtsov, Evegeny E. Perepelkin
(JINR)
Akira Goto, Masayuki Kase (RIKEN)
Toshinori Mitsumoto (SHI), Mitsuhiro Fukuda (RCNP)
2007/2/11
1
Layout of AVF Cyclotron
FC-I10
Cycro center
HyperECR
FC-I36
FC-C01a
１０GHｚECR
Room E7
AVF Cyclotron
Rext=0.714m
Bmax=1. 7 T
Vrf = 50 kV
h =2
F0=12~24MHz
2007/2/11
CRIB
FC-F0
2
Specifications of RIKEN AVF
K-value
Acc.Beam
Average Max.field
Extraction radius
Dee angle
Voltage
RF frequency
RF power
Main coil power
Circular coil
Harmonic coil
Vacuum pump
Manufactured
2007/2/11
70 MeV M/Q2
14N5+ 8.4 MeV/u
17 kG
714 mm
83°x2 Dees
peak 50 kV
12-24 MHz
2 x 50 kW
180 kW (1100 A)
8 pairs
4 pairs
1500 l/s TMP x1
4000 l/s CRYO x1
8500 l/s CRYO x1
1989
3
10 years over view
Contribution to AVF upgrade
１９９７
HyperECR
Atomic
Improve
SF ECR BT
Charge breeder
AVF Flat top
High power RF
Main & Trim coil
Center region
Improvements
Beam line
E7(CRIB)
SF clean up
PA
Monitor
DCCT
Cluster
Rf buncher
VIS
JSPS foundation
2007/2/11
Physics
１９９８
１９９９
２０００
Move to RIKEN
２００１
２００２
２００３
２００４
２００５
Installation
２００６
２００７
Operation
Metal IS
Accel-decel
Metal ions
Design
Cold model
hot model
Tuning
Beam test
Operation
R&D
Improvement
Insulator
Insulator
K=80
Condenser
Design
Deflector
H=2,3
H=1
Glaser lens
Modify
CRIB
Monitor
F0 focus
Move to RIKEN
Mesh
HiECR
Sputtering
Ion source
Rf buncher
Sputtering IS
VIS
SQUID monitor
4
The main point of AVF Upgrade
High Energy by K80,15N5+ 9MeV/u, 10pmA
Acceleration harmonics h = 1, 2, 3
ｈ＝３
ｈ＝１
ｈ＝２ (K-value）
center region
center region
①
②
②
①High energy by K value
reinforcement (acceleration h =
2)
→ Main coil & trim coil power
supply reconstruction
Now in
used
磁場 (T)
Directivity of upgrade of the RIKEN
AVF cyclotron (K70) *The
advancement which aimed at the
beam performance needed for
Nuclear Astrophysics research.
②Extension of an
acceleration energy domain
2
2007/2/11
4
15
Energy per Nucleon (MeV/u)
60
(Acceleration harmonics h = 1, 3)
→ Center region reconstruction
5
What is advanced in 2006?
1. Ion source
HyperECR Ion source / Metal ions
New ion source /Charge breeder ECR, Super ECR
2.
Development of AVF Cyclotron
Glaser lens
New AVF control room / Shared RIBF space
Dee RF / up to 52 kV
3. Upgrade of RIKEN/CNS AVF cyclotron
Design study of B-field, E-field, Centering, Inflector, Dee
chips, RF-shield, Injection, Extraction, Beam losses
2007/2/11
6
1. Ion Source
A. Hyper ECR
The half of the machine schedule of RIKEN cyclotron
uses the our HyperECR ion source.
B. Metal Ion Source
Si, Ca, P extracted from HyperECR
C. Super ECR
5.5K is continued
D. CBECR
Under the setup and vacuum test
2007/2/11
7
Y. Ohshiro
A. Hyper ECR Ion Source
Table 1
Ion
Energy
(MeV/u)
C10
(emA)
C01/I36
(%)
H+
14
9.1
11
H2+
3.97
2.8
8.23
6
9.5
1.55
2.6
7
Li2+
3.4
3.7
3.7
12 4+
C
7
1.3
3.3
13 4+
C
5.54
6.2
18.2
14 6+
N
8.2
5.2
34.7
15 4+
5
3.8
4.8
18
O5+
3.89
2.5
9.6
18
O6+
6.27
5.2
14.4
20
Ne7+
7
0.77
10.7
22
Ne７+
6.25
4.6
35.4
83
Kr23+
5.45
0.033
4.5
Li3+
N
★Extracted beam from AVF cyclotron
○The typical beam intensity in this year
(2006) is shown in the Table 1.
○Beam transmission efficiency of ECRAVF cyclotron (C01/I36) 35% is realized.
○The half of the machine schedule of
RIKEN cyclotron uses the our HyperECR
ion.source.
★Metal ion
○ Since the hot liner in the plasma
chamber is attached, Li ion generation
which used crucible can be stable and can
take out the ions of large intensity.
○By having doubled the capacity of
crucible, sample use time for one week or
more was realized.
2007/2/11
8
Y. Ohshiro
B. Development of Metal Ions
Y. Ohshiro
⑦
⑥
Fig. 2. The distance of the tips of the crucible and
the rod placed in the plasma chamber.
⑤
④
⑧
①
②
③
Table 2. Beam intensities of metallic ions obtained
Center
Ion
Second stage
ECR zone
First stage
ECR zone
wECR
This year
Bz (kG)
7
3+
Li
7 2+
Li
28 9+
Si
40
Ca11+
31 9+
P
Beam Intensity Charged Material
(emA)
75
200
32
Li pure metal (crucible)
Li pure metal (crucible)
SiO2 (rod)
50
29
CaF2 (rod)
P2O5 (Crucible)
★Sample insertion optimum position
○When a crucible or a rod is placed near 1st
ECR zone with efficient consumption rate, the
Fig. 1 Schematic drawing of Hyper ECR ion source
together with mirror field distribution used for 40Ca11+
ions production. ①Plasma chamber, ②RF wall, ③Solid
2007/2/11
material,
④Movable rod, ⑤Sextupole magnet, ⑥MC1,
⑦MC2, ⑧Extractor
metal ions of large intensity is obtained.
○The metal ions which can be used now
is shown in Table 2.
9
C. Development of SC-ECR Ion Source
Fig. 3. The superconductivity ECR ion source
installed by the test bench at RIBF-B1 (SC-ECR)
2007/2/11
Y. Ohshiro,
Tsukuba Univ.
★Purpose.
Extraction of multicharge ion beam
reinforcement by AVF cyclotron.
For example, since an Ar11+ ion beam is
100emA, compared with HyperECR, an about 3
times as many increase as this is expected.
* Present condition.
O It installed on the test bench of RIBF-B1.
O Electric power and cooling water were fixed.
O The freezer was overhauled.
O The cooling test of a superconductivity wire
was completed.
O Cooling temperature is stable at 5.5 k.
10
O A mirror coil power supply is under
manufacture.
D. Development of CNS Charge Breeder
Y. Ohshiro
Fig. 4. The charge breeder attached in
the electromagnetic analyzer
2007/2/11
* Purpose.
1) Inject Ar+ to CBECR, and
generates Ar11+ of large intensity.
2) Inject the metal ion from the
external metal ion source, and
generate the metal ion (Li, etc) of
large intensity.
* The feature.
1) More than Ar+ 10emA incidence.
2)Large differential pumping
system because of an improvement
of the vacuum pressure.
3) Strengthening of slowdown
efficiency.
* Present status.
1) Under an setup end and a
vacuum test.
2) Source test; end of the volume
type ion source = 40Ar+ 100 emA
O sputtering type ion source; Test
end.
Al+=66 [enA],
Li+=2 [enA]. .
11
14GHz RF
20
cm
0
⑤
Charge Breeder (continued)
③
②
④
①
⑧
⑦
TMP1
⑥
TMP3
TMP2
Voltage [kV]
Incident beam energy (10 keV +5 eV)
ΔV
0
Deceleration
E1
E2
Acceleration
E4
E3
Fig. 5. A cross-sectional view of the CNS
charges breeding system and potential map
for injection of interest ions. ①Volume
type ion source, ②④Insulator (MC nylon),
③Einzel lens (E1-4), ⑤Charge breeder
ECR ion source (CBECR), ⑥Plasma
chamber, ⑦Decelerator, ⑧Conical wall.
Table 3. Specification of each device
designed.
2007/2/11
First stage ion source (IS)
・Volume type IS
・Spattering type IS
・Extraction voltage
Beam transport system
・Max. Einzel lens voltage
・Deceleration voltage
Charge breeder ECRIS
・RF frequency
・Max. Mirror field
・Surface field of sextupol
・Correction coil
・Acceleration voltage
+ 15
+
E.g. Ar , N production
+
+
E.g. Li - Cu production
10 kV + 5 V
20 kV (E1 - E4 )
10 kV
14 GHz
12 kG
10.4 kG
13500 AT (C1 - C3 )
10 kV
12
Y. Ohshiro
2. Development of AVF in 2006
Glaser Lens
•Old Glaser lens was damaged by coil trouble
•New Glaser lens 'GLI38' is installed.
Pull out the old lens
2007/2/11
New Glaser lens
13
S. Watanabe
2. Development of AVF in 2006
Glaser Lens (continued )
Beam focusing power is improved up to 2 times (F ∝B2)
Performance
of GLI38
MCI vs GLI
350
Magnetic Field of Glaser Lens
GLI38
300
GLI37 (Imax)
(A)
current
Glaser lens GLI
(A)
Magnetic field (Gauss)
GLI38 (Imax)
New /
Old
250
系列1
系列2
系列3
系列4
200
150
100
GLI37
50
Distance from medium plane
0
With New GLI38
With Old GLI38
2007/2/11
0
200
400
600
800
1000
1200
(A)
Main coilMCIcurrent
(A)
14
S. Watanabe
2. Development of AVF in 2006
Beam Extraction
•Magnet channel and Deflector chips are improved.
•Extraction efficiency h is confirmed by using 14N6+ 8.2 MeV/u.
h~ 97%
obtained
I825
h = I825 /I645
I645
I825 ; after magnetic channel
I645 ; Before deflector entrance
8.2 MeV/u, Iecr=17emA,
I645=4.1emA, I825=4.0emA
2007/2/11
15
Goto/Kubono
Beam Extraction (continued)
Transmission efficiency of ESD, h = I825 /I645, is optimized by changing the Deflector
Chip & Magnetic Channel to new one’s. The h of 97 % was then obtained when ECR
current is 17 emA*1. The ratio of A/DrN. in proportional to h is evaluated as follows.
Table. Calculated A/DrN
SF
Te (MeV)
*2=measured by main probe
PSI
42 (p) 590 (p)
TRIU
MF
AVF
520
(p)
114.8 (14N6+)
Details of parameters
DrN =
Rext (m)
0.73
4.45
7.8
0.714
DrN
0.98
3.9
1.3
3.05/3.07*2
e (pmm mrad)
10
5
5
16
11
5
A (mm)
3.8
3.7
5.2
3.36/3.52*2
2.78
1.9
A/Dr
3.9 at R 0.95
2.4
1.10/1.17
A =N beam envelope
ext , DrN = Turn separation at Rext
0.91
0.6
(mm)
Rext
qnVd
 e  e  1 Te
n=number of Acc. Gap=4
*1 Data; Nov. 28, 06 R&D, Dec. 11, 06 Exp. 8.2 MeV/u, Iecr=17emA,
I645=4.1emA, I825=4.0emA. Beam emittance, eECR, of 110 pmm mrad
to be taken into account A/DrN., is derived from former Exp at
2007/2/11
E=6.4
MeV/u.
Vd= Dee voltage=45kV
eRext
p
e = e ecr  e
A=
 
16
3. Upgrade of RIKEN/CNS
AVF cyclotron - Subjects
1. TOSCA model construction
Magnetic field calculation
Electric field calculation
2. Study of Beam dynamics (examples)
AVF beam dynamics modeling in the 3D E-map
Bunch acceleration from the inflector exit to the final energy
Optimization perspectives
Transmission increase, beam quality improvement
3. Report / Proposal /Schedule
Report to RIKEN/CNS from Accelerator group
Proposal of New Inflector, RF shield, Dee chips for h=1, 3
2007/2/11
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1. TOSCA model construction
AVF magnetic field
►Field
at the surface are compared
with measurements in the radial
range 0-75cm.
The optimizations of remaining differences
in the simulations and measurements are still
in progress.
In the first stage, mesh
model is generated from
the drawings. In the
second stage, corrective
mesh model has been
made on the basis of
measurement.
2007/2/11
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A.S. Vorozhtsov
1. TOSCA model construction
AVF Electric Field
Central region model
Acceleration region model
Number of nodes = 3.2 million.
grid size in the very
center is less than 1
mm
2007/2/11
19
A.S. Vorozhtsov
1. TOSCA model construction
Acceleration region DC-E map
R(150mm-750mm)
2007/2/11
20
A.S. Vorozhtsov
1. TOSCA model construction
Central region DC-E map Rmax=149mm
2007/2/11
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A.S. Vorozhtsov
2. Study of Beam Dynamics
Confirmation of Inflector parameter and Trajectory
B & E fields model are taken into account the beam dynamics calculation.
Inflector (center) , RF shield and Dee chips are shown.
2007/2/11
22
A.S. Vorozhtsov & E.E. Perepelkin
2. Study of Beam Dynamics
Confirmation of Acceleration parameter and Trajectory
Injected bunched beam is accelerated along with reference orbits
2007/2/11
23
A.S. Vorozhtsov & E.E. Perepelkin
2. Study of Beam Dynamics
Flat-top acceleration
FT OFF
ESD
Expanded radial distribution
2007/2/11
FT ON
ESD
Narrowed radial distribution
24
E.E. Perepelkin
3. Report / Proposal /Schedule
• Resume of the RIKEN/CNS AVF cyclotron
upgrade meeting is distributed to the meeting
member.
• Presentations at the RIKEN/CNS AVF cyclotron
upgrade meeting are distributed to the meeting
member.
• Report on Study of h=2 acceleration will be
published
• Following meeting will be held in August, 2007.
2007/2/11
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Summary
• Status of ECR Ion sources
HyperECR, Metal IS, Super ECR, Charge breeder are
advanced.
• Development of the AVF cyclotron
Axial injection line is improved. Dee voltage and Extraction
efficiency are improved.
• Upgrade of AVF cyclotron
TOSCA model of AVF is completed, Beam dynamics model
is advanced, Center region for h=1, 3 is to be proposed.
Fine tuning of the TOSCA model is required. electrode, etc.
2007/2/11
26