Transcript Slides
LANL Proposals to Support ILC
Proposers: T. Tajima and W. A. Reass
Rich Sheffield
Senior Advisor
LANSCE Division
Los Alamos National Laboratory
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Proposal for WBS 3.9.3: Cavity Processing
Propose WBS 3.9.3.5: Gradient Spread Investigation
• With a small amount of modifications to our
existing facilities, we will be able to process and
test up to eight 9-cell cavities in one cooldown
cycle, which saves time and cryogens cost.
• While testing one cavity at a time is typical,
testing multiple cavities simultaneously after the
same process/procedure will give a more accurate
evaluation of the process/procedure in a shorter
time.
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Proposal is to improve quality and
consistency in cavity production
• Present gradient spread is 20 ≤ E(MV/m) ≤ 35 at DESY for
the electro-polished cavities
• It is difficult to find the reason for the spread due to a
variety of factors that could cause the spread, e.g., wrong
EP parameters, insufficient rinsing, particle contamination
during the following processes, etc.
• We do not have statistically enough data to predict the
yield of successful cavities.
• A number of tests and statistical analysis are required in
the next year or two.
• LANL has facilities and resources available for this
purpose with a small scale modifications to our existing
equipment.
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LANL has facilities available for testing a
number of SRF cavities
38” cryostat inserts
2600 ft2 class-100 Clean
room, 10-ft high
Ultra-pure water with 2000 G/day
and 1500 G storage tank
140 ft.
Vertical cryostats with
movable radian shield
100 ft.
High-pressure rinse in a clean room.
Pumps for cryostats
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Control, tuning
8 cavities
Proposed Configuration
of the Testing Setup
• Input coupler will be a fixedlength coupler. (The optimum
coupler length will be
determined by previous data
and/or initial tests.)
Circle A
RF feed
• The cavity position can be
adjusted along circle A
Vacuum manifold
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Work to be performed
• Confirm the quality of the facility (clean room,
ultra-pure water system, high-pressure rinsing
system, BCP, etc.)
• Modify existing RF measurement system for 1.3
GHz cavities.
• Modify fixtures for high-pressure water rinsing
system and cryostat insert.
• Test cavities after various process/procedures
(EP/BCP parameters, HPR parameters, etc.)
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Cost and Schedule
Labor
(K$)
M&S
(K$)
Indirect cost
(K$)
Total cost
(K$)
154
357
230
741
January 31, 2007: Build RF measurement system for 1.3
GHz cavities and test several single- and/or 9-cell cavities.
March 31, 2007: Modify the cavity insert, vacuum system
and RF feed-throughs to accommodate up to eight 9-cell
cavities.
September 30, 2007: Get a statistically-significant data set to
analyze the gradient data spread occurring from various
cavity treatments and provide appropriate feedback to the
various collaborators.
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Expectations for FY08 and beyond
• The work will continue to narrow the spread
of the cavity performance until it reaches an
acceptable level.
• Then, the focus will be shifted to the
investigation into how to simplify various
processes to reduce time and cost for
processing cavities toward industrialization
while maintaining the narrow spread.
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Proposal for WBS 3.8.4: Optimized
Converter-Modulator Development
• Developed for Oak Ridge SNS accelerator
• Can be optimized for ILC application
• Should save ~$100M in RF systems cost
and be electrically efficient
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Los Alamos High Frequency “Polyphase Resonant Power
Conditioning” Compared To Conventional 60Hz
Technology Is Significantly Smaller
SNS 10 Megawatt Pulse, 20 KHz, 140 kV
Polyphase Resonant Converter-Modulator
• Developed for Oak Ridge SNS Accelerator
• Can be Optimized for 30 MW Long Pulse
• Operates 2 Multi-Beam Klystrons
• Resonant Conversion is Fault Tolerant
• Can Operate with Kilometer Cable Lengths
• No Crowbars Needed
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Polyphase Resonant Power Conditioning Uses New
LANL/LANL Funded Technology Developments
• Low Inductance Self-Clearing Capacitors
– Thomson Passive Components (AVX), France
• Low Inductance High Power Capacitors
– General Atomics Energy Products, San Diego, Ca.
• Nanocrystalline Core Manufacturing
– MK Magnetics (Stangenes), Adelanto, Ca.
– Uses Hitachi FT-3 Alloy
• New Engineering Techniques
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Polyphase Resonant Voltage Multiplication
Resonant Rectification
Self DeQing (No crowbars and self protective)
Snubberless IGBT Switching
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Tank Basket Assembly:
1 MW Average, 10 MW Long Pulse
Filter Network
Transformers
Tank Basket Assembly
Output Sockets
&
Varistor Assembly
Transformer Resonating
Capacitors
Oil Pump & Voltage Divider
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Diode Rectifiers
Operational Efficiency
• 140 kV (5 MW Klystron), 800 kW Average Power
– ~94% efficient
• 75 kV, “12 Pack” (550 kW klystrons)
– ~93% efficient
• “Zero-Voltage-Switching” works
• Can be optimized to ~96% efficient for ILC Application
• Can Achieve ~90% Overall System Pulse Utilization
Efficiency
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View Of Proposed 30 MW ILC Pentaphase
Converter-Modulator System
Size: 7’ X 8’ X 14’
• Operates 2 MBK’s
• Fault tolerant, automatic fault “ridethrough”
• Can operate with long output cables
(over 1 kilometer)
• Cannot harm klystron
• Multiple units operate from
common DC bus
• Lower IGBT Loading than SNS
Application
–
–
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900KW / IGBT (SNS)
750KW / IGBT (ILC)
Suggested Development Path
• Operate SLAC Unit
• Upgrade SLAC System to one MBK Operation
– “Dually” Switch Plate
– Higher Current Diode Assemblies
• Test with >1KM Cable
• Improve Adaptive Control Method
• Complete Development of Pentaphase “Dually”
– Operate 2 MBK’s
– Operate with >1KM Cable
– Evaluate Adaptive Controls
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Cost and Schedule
Cost Element
Direct
Indirect
Staff
$94 k
$102 k
Designer
$70 k
$76 k
Tec-6
$70 k
$76 k
M&S
$200 k
$76 k
Total
$434 k
$330 k
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Conclusion
• Polyphase Resonant Power Conditioning design topology and
techniques now proven
– Easily Optimized
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Better understanding of component performance
Inherently self and load protective
Significant change in high power, power conditioning topology
Testing, teaming, and prototypes for ILC applications
Design is very cost effective (should save ~$100M in RF
systems cost) and electrically efficient
• Installation space minimized
• Beam Tunnel space minimized
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