DEVELOPMENT OF INDUCTION MODULATOR FOR HIGH POWER ACCELERATORS

1
DEVELOPMENT OF INDUCTION MODULATOR FOR HIGH
POWER ACCELERATORS

• K.Horioka1, M.Nakajima1, M.Nagata1, E.Hotta1,
  M.Shiho1
• K.Tatayama2, E.Nakamura2, K.Torikai2
• J.Kishiro3, M.Watanabe3,
• T.Kikuchi4, T.Katayama4
• Department of Energy Sciences, Tokyo Institute of
  Technology1,
• High Energy Accelerator Research Organization,
  KEK2
• Japan Atomic Energy Research Institute, JAERI3
• Research Center for Nuclear Science, University
  of Tokyo4

2
HIF Drivers (High Power Accelerators) have
following issues
R.O.Bangerter Fusion Engineering and Design 44,
p.71 (1998)
1. Ion Source Injector Section
2. Beam Acceleration Minipulating Section
3. Final Bunching, Focusing and Target
Irradiation Section
3
RD on Repetitive, Controllable High Average
Power Induction Voltage Modulators
4
Controlled waveforms are essential for beam
acceleration manipulation in high average power
accelerators
Bi-directional
Asymmetric
V
V
Time
Time
Acceleration

KEK-Recirculator
Buncher
5
Experimental Arrangement for FET-Driven Module
Element and Typical Output Waveforms
Typical Core Voltage Current
M.Watanabe et.al., Rev. Sci. Instr., A464, p.440
(2001)
6
Magnetization curves and core loss scaling are
clarified at minor hysteresis loops
Magnetization Curves
Core-loss Scaling
7
Examples of module voltage, core-current, and
Hysteresis Loops (For Stacked Modulator)
M.Watanabe et.al., Rev. Sci. Instr., A464, p.440
(2001)
8
R D on Solid-state-SW based Induction
Pulse-Modulator at TIT
SIThy-Based Power Modulator
FET-Based Power Modulator
SI Thyristor T335R-40 (NGK Insulators Ltd.
Co.) Peak Hold Off Voltage 4 kV DC Hold Off
Voltage 3.2 kV Effective On Current 200 A Peak
On Voltage 5.4 V
9
Operation Performance of Induction
Pulse-Modulator at KEK (RD3)
Output- 2.6kV (100Ohm), Rep-rate1MHz
Set-up for Induction Accelerating Module
Pulse Modulator
Trans. Cable
DC Power Supply
Pulse Modulator (Inner Structure)
Single period
by KEK Induction Synchrotron Project
10
Concept of Induction Synchrotron
Principle
Image of Accelerator
RF Synchrotron
for confinement
Acceleration gap
RF voltage
Super-bunch
RF bunch
Combined function of accel./confinement
Voltage with gradient
Modulator Circuit
Pulse voltage
for acceleration
for confinement
Separate function
Induction Synchrotron
MHz operation -gt serious heat-deposit
K.Takayama and J.Kishiro, Induction
Synchrotron, Nucl. Inst. Meth. A451, 304(2000).
11
Exploratory Research Project (2003-2007) Super-bun
ch Acceleration Experimental Demonstration of
Induction Synchrotron Project leader Ken
Takayama(KEK)
Laser-asist H- injection
Feed-back system Impedance management

• Applications
• Proton Driver
• Modification
• of existing RF
• Synchrotrons
• Super-bunch
• Hadron Collider

2000-2003
Induction Acceleration System RD,
manufacturing Power Modulator Cavity
Super-bunch Acceleration in KEK 12GeV PS
2003 - 2005
Switching element RD
MOSFET SI-Thy in low temp. SiC-MOSFET
2006 - 2010
Budget US 5M In collaboration with TIT,
JAERI and Japanese industries
12
Operation Performance of Pulse-Modulator at KEK
(RD)
Output2.6kV?Rep-rate1MHz
Set-up for Induction Accelerating Module
Pulse Modulator
Trans. Cable
DC Power Supply
Vacuum duct
Pulse Modulator (Inner Structure)
Timemsec
0 1
2 3
4 5
Single period
by KEK Induction Synchrotron Project
13
Using induction modulator, beam acceleration and
manipulation will be demonstrated at KEK 12GeV PS
Main Ring circumference339m
500MeV Booster
40MeV H- - Linac
750kV Pre-injector
Experimental Hall
by KEK Induction Synchrotron Project
14
Arrangement of Devices/Cables
Pulse modulator
12GeV Main Ring
Induction Accelerating Cavity
DC Power Supply
Booster
CW 1MHz 2kV/unit, 250nsec FT operation
15
Impedance Management is Critical for Waveform
Control
Miss-matching
Resonant Condition
Induction Modulator (L,C)
Power Transmission Line (Z0)
HV (Z0)
16
Concept for Waveform Control
Typical Waveform of Module (4kV-100nsec-kHz)
Parallel Stacking (4kV-500nsec)
Module Structure Operational Range
100kV-kHz(FET-Driver) Waveform Stacking (Can
make Step, Rising, Sinusoidal Waveforms) Robust
against Load Condition
Series Stacking (20kV-100nsec)
Voltage Driver
17
Induction Cell based on Sinusoidal Modulator

• Module Structure based on Sinusoidal Unit
• Operational Range 100kV-kHz(FET-Driver)
• Waveform Stacking
• (Can make Step, Rising, bipolar)
• Robust against Load Condition

Test Stand for Basic Induction Unit
Voltage Driver
Induction Modulator Unit
18
RD of Induction Modulator at Intermediate
Parameter Region (10s kV-kHz level ) is also
progressing
Operational Regime
Pulse Power Technology
100
This Project
Voltage kV /Module
10
KEK Project
H.V.
1
PAV100kW
10
1k
1M
Operational Frequency ( Hz )
Voltage Modulator driven by SI-Thy
Basic Concept of Induction Cavities((3.2kV8)4
100kV)
19
Summary

• We have
• Developed a Controllable Induction Cell based on
  Modular Structure
• Clarified the magnetic characteristics at minor
  hysteresis loops
• Operated the Module Elements at -2.5kV-1MHz
• Installed a Test Module in the 12GeV Proton
  Synchrotron at KEK
• We are planning
• to make demonstration of beam manipulation at KEK
• to continue component development (kHz-100kV
  Induction Unit)
• to make programmed switching, feedback control of
  the device

20
Concluding Remarks

• Although there is a long missing link between the
  high flux ion injector and the final transport
  region in HIF driver design , we believe that we
  will be able to find out a solution based on the
  efforts for these issues.
• We think that these efforts allow us to extend
  the design space of accelerator system and
  significant RD efforts are on going in Japan,
  at government laboratory (KEK) and also at
  Universities (TIT, Utsunomiya, Tokyo and Osaka)

21
HIF driver based on High-Rep-rate, bi-polar
inductive acceleration

• Basic concept
• Positive and (Negative) Ions are accelerated by
  High-Rep rate (kHz) inductive
• Bi-polar waveforms
• Longitudinal stacking of them in re-circulator
  rings with MHz Induction Modulators
• Advantages
• Can extremely reduce the core volume and the ion
  source requirement
• Can avoids a risk of transverse beam merging

MHz Induction Modulators
Re-circulator for making a super-bunch
High Rep-rate Ion Injector
High Rep-rate (kHz) Induction Modulators
Final Buncher
Re-circulator for making a super-bunch
Merging
Conceptual Diagram of HIF Driver based on High
Rep-rate Induction Technology (By T.Kikuchi,
Okamura, K.Horioka)
22
Thank you for your attention.