Transcript Radiological Issues of ILC

가속기 개발 현황
1. ILC-Korea and International Collaboration
2. Modulator R&D
제3회 한국 국제선형가속기 워크숍
(The Third Korean ILC Workshop)
건국대학교
2005년 4월 1일-4월 2일
ILC-Korea Task Force Team
PAL/POSTECH
1. ILC-Korea and
International Collaboration
ILC-Korea Task Force Team, PAL/POSTECH
H. Matsumoto, KEK
ILC-Korea Task Force Team at PAL
TFT Head: W. Namkung
WG1: J. Choi, M.H.Cho
WG2: J.S.Oh, W.H.Hwang
WG3: S.J.Park, E.S.Kim
WG4: J.Y.Huang, H.S.Lee
WG5: S.H.Kim, Y.U.Son
Possible PAL Contributions
- Diagnostics (J. Y. Huang)
- Damping Ring (E. S. Kim)
- Injector, MBK Development (J. S. Park)
- Klystron Power Supply (J. S. Oh)
- RF Power Distribution (W. H. Hwang)
- Beam Dump (H. S. Lee)
- Superconducting Cavity (Y. U. Son)
H. Matsumoto, KEK
Collaboration with PAL/POSTECH
1 9 8 9 : Prof. Won Namkung (PAL) visit KEK to investigate high power
klystron for 2-GeV injector linac. We started to collaborate for
linac technologies.
1994: Prof. Moo-Hyun Cho (PAL) introduce us a new modulator technology,
which use an inverter power supply for the PFN charging.
(compact: 48cm x 35cm x 65 cm, stable: +/-0.1%)
1996~1997: Dr. Jong-Seok Oh (PAL) developed a first new klystron
modulator (smart modulator No.1) using inverter power supply for
the C-band 50-MW klystron. (compact: 1.5m x 2m x 1.2m, low
EMI, cost reduction)
2002~2003: We (KEK/RIKEN/PAL) developed second smart modulator, which
is oil filled closed metal case. (compact: 1.5m x 1m x 1m, low EMI,
low cost)
2003~2004: Shanghai light source group accepted the concept of smart
modulator No.1, and made it their self.
We are going to collaborate each other for the modulator and brazing
technologies as a starting period.
H. Matsumoto, KEK
Collaboration with Asian Area for ILC 45 MV/m
Possible items are;
1) Power modulator
We have developed the first smart modulator with PAL/POSTECH in
1997 at KEK. In 2003, this modulator concept was accepted in China for
the Shanghai light source. They fabricated it there themselves, and it
was tested in May 2004. Also, RIKEN developed an oil-filled closed type
modulator, which was evolved from first modulator.
We would like to develop the new power modulator, which realize the
electric circuit simple, compact size and low cost.
2) Input coupler  very urgent work
It was just started to develop the new coupler, which meet an aim
of the high gradient acceleration at 45 MV/m. One of key technologies
are materials and brazing.
We would like to realize structure simple, good reliability and low
cost.
3) Waveguide components
It was just started only a paper work. So far, waveguide use
natural air with atmosphere pressure, which seems to be not enough
margin at 5-MW peak rf power and 1-msec pulse width. We would like
to develop vacuum type waveguide components, especially circulator.
2. ILC Modulator R&D
J. S. Oh, W. Namkung, PAL/POSTECH
H. Matsumoto, KEK
TESLA 500/800 RF Requirements
TESLA Energy Upgrade
TESLA500
TESLA800
TESLA1000
572 RF Unit
606 RF Unit
606 RF Unit
1 Modulator/Unit
1 Klystron/Unit
3 Cryomodule/Unit
2 Modulator/Unit
2 Klystron/Unit
3 Cryomodule/Unit
3 Modulator/Unit
3 Klystron/Unit
3 Cryomodule/Unit
Total
572 Modulators
572 Klystrons
1,716 Cryomodules
Total
1,212 Modulators
1,212 Klystrons
1,818 Cryomodules
Total
1,818 Modulators
1,818 Klystrons
1,818 Cryomodules
Power Supply for 10 MW Klystron
Klystron Gun Voltage
115 (120) kV
Klystron Gun Current
130 (140) A
HV Pulse Width (70% to 70%)
< 1.7 (1.7) ms
HV Rise and Fall Time (0 to 90%)
<0.2 (0.2) ms
HV Flat Top
1.37 (1.5) ms
Pulse Flatness during Flat Top
< ±0.5 (±0.5)%
Pulse-to-Pulse Voltage Fluctuation
< ±0.5 (±0.5)%
Maximum Energy Deposit of Gun Spark
< 20 (20) J
Pulse Repetition Rate
5 (10) Hz
Transformer Turn Ration
1:12
Filament Voltage
9 (11) V
Filament Current
50 (60) A
Principle of TESLA Modulator
• Pulse cable : 4 parallel, 6.45 Ohm, max. ~2.8 km
• Pulser unit : 2.8m(L) x 1.6m(W) x 2.0 m(H)
• Pulse transformer tank : 2m(L) x 1.2m(W) x 1.4m(H), 6.5 ton!
New Magnetic Material is available!
FINEMETTM : Nano-crystalline Fe-based Soft Magnetic Material
with High Saturation Flux Density and Low Core Loss
What is FINEMET?
The precursor of FINEMET is amorphous ribbon (non-crystalline) obtained by rapid quenching
at one million °C/second from the molten metal consisting of Fe, Si, B and small amounts of
Cu and Nb. These crystallized alloys have grains which are extremely uniform and small,
“about ten nanometers in size”. Amorphous metals which contain certain alloy elements show
superior soft magnetic properties through crystallization.
It was commonly known that the characteristics of soft magnetic materials are “larger crystal
grains yield better soft magnetic properties”. Contrary to this common belief, soft magnetic
material consisting of a small, “nano-order”, crystal grains have excellent soft magnetic
properties.
Crystallization Process of FINEMET
Amorphous metal as a starting point, Amorphous  Cu-rich area  the nucleation of bcc Fe
from Cu bcc  Fe(-Si) shows the crystallization process. At the final stage of this
crystallization process, the grain growth is suppressed by the stabilized remaining amorphous
phase at the grain boundaries. This stabilization occurs because the crystallization temperature
of the remaining amorphous phase rises and it becomes more stable through the enrichment of
Nb and B.
Synergistic effects of Cu addition, “which causes the nucleation of bcc Fe” and Nb addition,
“which suppresses the grain growth” creates a uniform and very fine nano-crystalline
microstructure.
Features of FINEMET
1) Satisfy both high saturation magnetic flux density and high permeability
High saturation magnetic flux density comparable to Fe-based amorphous metal. High
permeability com-parable to Co-based amorphous metal.
2) Low core loss
1/5th the core loss of Fe based amorphous metal and approximately the same core loss
as Co-based amorphous metal.
3) Low magnetostriction
Less affected by mechanical stress. Very low audio noise emission.
4) Excellent temperature characteristics and small aging effects
Small permeability variation (less than ±10%) at a temperature range of -50 °C~150 °C.
Unlike Co-based amorphous metals, aging effects are very small.
5) Excellent high frequency characteristics
High permeability and low core loss over wide frequency range, which is equivalent to
Co-based amorphous metal.
6) Flexibility to control magnetic properties “B-H curve shape” during annealing
Three types of B-H curve squareness, high, middle and low remanence ratio,
corresponding to various applications
Modulator R&D items
1.
2.
3.
4.
5.
6.
7.
8.
Efficiency improvement
Pulse transformer with new materials
Cost reduction
New switching devices
New designs
Charging supply technology
Power distribution
Standardization