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Working Group Summaries: Working Group Summaries: AcceleratorAccelerator
RF Technology and Structures
Systems and Instrumentation
Matthias Liepe
Cornell University
RF Technology and StructuresRF Technology and Structures
We are almost there,
But still a lot can and needs to be done.
Accelerator Working Group: RF Technology and StructuresAccelerator Working Group: RF Technology and Structures
Monday, July 14, 8:30-10:30 a.m.
8:30-8:55 Warm and Cold RF Structures Hasan Padamsee
8:55-9:15 Technology Development Program for a Oleg Nezhevenko / Future 34-GHz Linac Vyacheslav Yakovlev
9:15-9:30 Acoustic Localization of RF Structure Breakdowns George Gollin
9:30-9:45 Optimized Cavity Shape for TESLA Valery Shemelin
9:45-10:00 1500 MHz Nb Cavity made of Electro- polished Half-Cells Rongli Geng
10:00-10:15 DC Breakdown Studies Greg Werner
10:15-10:30 Control of Beam Loss in High-Repetition Rate High-Power PPM Klystrons Mark Hess
Accelerator Working Group: RF Technology and StructuresAccelerator Working Group: RF Technology and Structures
Monday, July 14, 8:30-10:30 a.m.
8:30-8:55 Warm and Cold RF Structures Hasan Padamsee
8:55-9:15 Technology Development Program for a Oleg Nezhevenko Future 34-GHz Linac
9:15-9:30 Acoustic Localization of RF Structure Breakdowns George Gollin
9:30-9:45 Optimized Cavity Shape for TESLA Valery Shemelin
9:45-10:00 1500 MHz Nb Cavity made of Electro- polished Half-Cells Rongli Geng
10:00-10:15 DC Breakdown Studies Greg Werner
10:15-10:30 Control of Beam Loss in High-Repetition Rate High-Power PPM Klystrons Mark Hess
20,600L = 21 km
18,500L = 11.1 km
Why 11.4 GHz?Peak RF Power needed to reach gradient 1/√ frequency
1.3 GHz
Niobium
1 m
RF Losses = 55 W ea.
Run pulsed at a duty factor of 0.7%
Need RF peak power = 1.2x109 watt
Dynamic heat load at 2 K = 10 kW
+ Static + safety =
30 kW refrigerator..AC power = 22 MW
RF Losses = 80 MW/m !
Total peak RF power = 1012 watt
Duty Factor = 0.006%
AC Power = 150 MW
Start withEa-loaded=50 MV/m(65MV/m-unloaded)Fewer structures
Strategy: start with 23.5 MV/mStructures tested to 35 MV/m before installation Copper
11.4 GHz
The best !
1.0E+09
1.0E+10
1.0E+11
0 10 20 30 40Eacc [MV/m]
Q0
CWCW after 20KCHECHIA 10 Hz ICHECHIA 5 HzCHECHIA 10 Hz IICHECHIA 10 Hz III
AC73 - Vertical and Horizontal Test Results1011
109
1010
37 MV/m in Fully Equppied Cavityi.e. high power test and 1/8th of a TTF Linac module
Accelerator Working Group: RF Technology and StructuresAccelerator Working Group: RF Technology and Structures
Monday, July 14, 8:30-10:30 a.m.
8:30-8:55 Warm and Cold RF Structures Hasan Padamsee
8:55-9:15 Technology Development Program for a Oleg Nezhevenko Future 34-GHz Linac
9:15-9:30 Acoustic Localization of RF Structure Breakdowns George Gollin
9:30-9:45 Optimized Cavity Shape for TESLA Valery Shemelin
9:45-10:00 1500 MHz Nb Cavity made of Electro- polished Half-Cells Rongli Geng
10:00-10:15 DC Breakdown Studies Greg Werner
10:15-10:30 Control of Beam Loss in High-Repetition Rate High-Power PPM Klystrons Mark Hess
Technology Development Program for a Future 34-GHz Linac
Oleg Nezhevenko
• Goal: extend present 11 GHz RF technology by a factor of 3 to 34 GHz with hope to increase achievable gradients.
• Built a 34 GHz magnicon (10 MW, 0.5 s) and cavity for pulsed heating tests.
• Designed a 34 GHz 19 cell accelerating cavity.
Accelerator Working Group: RF Technology and StructuresAccelerator Working Group: RF Technology and Structures
Monday, July 14, 8:30-10:30 a.m.
8:30-8:55 Warm and Cold RF Structures Hasan Padamsee
8:55-9:15 Technology Development Program for a Oleg Nezhevenko Future 34-GHz Linac
9:15-9:30 Acoustic Localization of RF Structure Breakdowns George Gollin
9:30-9:45 Optimized Cavity Shape for TESLA Valery Shemelin
9:45-10:00 1500 MHz Nb Cavity made of Electro- polished Half-Cells Rongli Geng
10:00-10:15 DC Breakdown Studies Greg Werner
10:15-10:30 Control of Beam Loss in High-Repetition Rate High-Power PPM Klystrons Mark Hess
Accelerator Working Group: RF Technology and StructuresAccelerator Working Group: RF Technology and Structures
Monday, July 14, 8:30-10:30 a.m.
8:30-8:55 Warm and Cold RF Structures Hasan Padamsee
8:55-9:15 Technology Development Program for a Oleg Nezhevenko Future 34-GHz Linac
9:15-9:30 Acoustic Localization of RF Structure Breakdowns George Gollin
9:30-9:45 Optimized Cavity Shape for TESLA Valery Shemelin
9:45-10:00 1500 MHz Nb Cavity made of Electro- polished Half-Cells Rongli Geng
10:00-10:15 DC Breakdown Studies Greg Werner
10:15-10:30 Control of Beam Loss in High-Repetition Rate High-Power PPM Klystrons Mark Hess
The hard limit for the increase in accelerating gradient in s.c. cavities is the surface magnetic field.
Optimize cavity shape:One can, for example, sacrifice 20 % of electric field to gain 10
% in magnetic field and so increase the Acc. Rate by 10 %.
old new
Accelerator Working Group: RF Technology and StructuresAccelerator Working Group: RF Technology and Structures
Monday, July 14, 8:30-10:30 a.m.
8:30-8:55 Warm and Cold RF Structures Hasan Padamsee
8:55-9:15 Technology Development Program for a Oleg Nezhevenko Future 34-GHz Linac
9:15-9:30 Acoustic Localization of RF Structure Breakdowns George Gollin
9:30-9:45 Optimized Cavity Shape for TESLA Valery Shemelin
9:45-10:00 1500 MHz Nb Cavity made of Electro- polished Half-Cells Rongli Geng
10:00-10:15 DC Breakdown Studies Greg Werner
10:15-10:30 Control of Beam Loss in High-Repetition Rate High-Power PPM Klystrons Mark Hess
Motivation: Do heat treatment and electropolishing on half cells to reduce cost in s.c. cavity production.
Accelerator Working Group: RF Technology and StructuresAccelerator Working Group: RF Technology and Structures
Monday, July 14, 8:30-10:30 a.m.
8:30-8:55 Warm and Cold RF Structures Hasan Padamsee
8:55-9:15 Technology Development Program for a Oleg Nezhevenko Future 34-GHz Linac
9:15-9:30 Acoustic Localization of RF Structure Breakdowns George Gollin
9:30-9:45 Optimized Cavity Shape for TESLA Valery Shemelin
9:45-10:00 1500 MHz Nb Cavity made of Electro- polished Half-Cells Rongli Geng
10:00-10:15 DC Breakdown Studies Greg Werner
10:15-10:30 Control of Beam Loss in High-Repetition Rate High-Power PPM Klystrons Mark Hess
• DC breakdown studies on copper and niobium surfaces.
• found starbursts and craters after breakdowns
• found Manganese on all heat treated copper samples
50 um
145MV/m
Accelerator Working Group: RF Technology and StructuresAccelerator Working Group: RF Technology and Structures
Monday, July 14, 8:30-10:30 a.m.
8:30-8:55 Warm and Cold RF Structures Hasan Padamsee
8:55-9:15 Technology Development Program for a Oleg Nezhevenko Future 34-GHz Linac
9:15-9:30 Acoustic Localization of RF Structure Breakdowns George Gollin
9:30-9:45 Optimized Cavity Shape for TESLA Valery Shemelin
9:45-10:00 1500 MHz Nb Cavity made of Electro- polished Half-Cells Rongli Geng
10:00-10:15 DC Breakdown Studies Greg Werner
10:15-10:30 Control of Beam Loss in High-Repetition Rate High-Power PPM Klystrons Mark Hess
Pencil Beam Model (Presented at Arlington
Meeting)
Finite Size Beam Model(New)
Diagrams of Bunched Beam Models
L
aVz
r
L
ra Vz
x
y
z
B
Theoretical studies: Why do some klystrons show beam loss (and some don’t)?
0.0 0.3 0.6 0.9 1.2 1.5af/bbc
0.0
0.1
0.2
0.3
0.4
0.5
8c2 I b/
c,
rmsa
2 I A
50 MW XL-PPM75 MW XP-175 MW XP-350 MW (C-Band)75 MW PPM-1
0.0 0.3 0.6 0.9 1.2 1.5af/bbc
Red Curve: Pencil Beam
Blue Curves: rb/a=0.5
bz/a=0.71
Comparison of Bunched Beam Models to Experiment
bz/a=0.36
bz/a=0.0
Systems and InstrumentationSystems and Instrumentation
Good controls and instrumentation are essential for LC.
Much work in progress, but a lot more needs to be done.
Accelerator Working Group: Systems and InstrumentationAccelerator Working Group: Systems and Instrumentation
Monday, July 14, 10:55-12:5510:55-11:15 Accelerator Instrumentation RD Marc Ross11:15-11:35 Prototype Synchrotron Radiation Telescope Jim Alexander11:35-11:55 Design and Fabrication of a Radiation-Hard
500 MHz digitizer K K Gan11:55-12:15 Nanometer resolution Beam Position Monitors Marc Ross12:15-12:35 Nanometer BPM supports and movers Jeff Gronberg
Tuesday, July 15, 1:50-3:50 p.m.1:50-2:10 TTF data acquisition Tim Wilksen2:10-2:30 Beam size diagnostics using diffraction radiation Bibo Feng2:30-2:50 A0 coherent radiation diagnostics Court Bohn
Accelerator Working Group: Systems and InstrumentationAccelerator Working Group: Systems and Instrumentation
Monday, July 14, 10:55-12:5510:55-11:15 Accelerator Instrumentation RD Marc Ross11:15-11:35 Prototype Synchrotron Radiation Telescope Jim Alexander11:35-11:55 Design and Fabrication of a Radiation-Hard
500 MHz digitizer K K Gan11:55-12:15 Nanometer resolution Beam Position Monitors Marc Ross12:15-12:35 Nanometer BPM supports and movers Jeff Gronberg
Tuesday, July 15, 1:50-3:50 p.m.1:50-2:10 TTF data acquisition Tim Wilksen2:10-2:30 Beam size diagnostics using diffraction radiation Bibo Feng2:30-2:50 A0 coherent radiation diagnostics Court Bohn
• Overview of beam instrumentations and controls; importance and influence on cost, performance and reliability of LC.
• Examples:
• correlation monitors
• Multibunch behavior of u-wave cavity BPM’s
• Long. phase space diagnostics based on deflecting RF
• Marc’s Conclusion:
•HEP must aggressively attack Controls/Instrumentation issues
Accelerator Working Group: Systems and InstrumentationAccelerator Working Group: Systems and Instrumentation
Monday, July 14, 10:55-12:5510:55-11:15 Accelerator Instrumentation RD Marc Ross11:15-11:35 Prototype Synchrotron Radiation Telescope Jim Alexander11:35-11:55 Design and Fabrication of a Radiation-Hard
500 MHz digitizer K K Gan11:55-12:15 Nanometer resolution Beam Position Monitors Marc Ross12:15-12:35 Nanometer BPM supports and movers Jeff Gronberg
Tuesday, July 15, 1:50-3:50 p.m.1:50-2:10 TTF data acquisition Tim Wilksen2:10-2:30 Beam size diagnostics using diffraction radiation Bibo Feng2:30-2:50 A0 coherent radiation diagnostics Court Bohn
• Present: explore parameter space, identify key issues.
• Next: system pro-design
• Future: Test structures,…
• Image synchrotron radiation from damping rings
Snapshot from transverse bunch shape, single bunch resolution
Accelerator Working Group: Systems and InstrumentationAccelerator Working Group: Systems and Instrumentation
Monday, July 14, 10:55-12:5510:55-11:15 Accelerator Instrumentation RD Marc Ross11:15-11:35 Prototype Synchrotron Radiation Telescope Jim Alexander11:35-11:55 Design and Fabrication of a Radiation-Hard
500 MHz digitizer K K Gan11:55-12:15 Nanometer resolution Beam Position Monitors Marc Ross12:15-12:35 Nanometer BPM supports and movers Jeff Gronberg
Tuesday, July 15, 1:50-3:50 p.m.1:50-2:10 TTF data acquisition Tim Wilksen2:10-2:30 Beam size diagnostics using diffraction radiation Bibo Feng2:30-2:50 A0 coherent radiation diagnostics Court Bohn
• radiation hard (> 60 MRad)• somewhat beyond state-of-the-art• started with design, are funded by DOE for
design/simulation in first year• goal: has most circuit blocks ready for
prototyping by end of first year
Accelerator Working Group: Systems and InstrumentationAccelerator Working Group: Systems and Instrumentation
Monday, July 14, 10:55-12:5510:55-11:15 Accelerator Instrumentation RD Marc Ross11:15-11:35 Prototype Synchrotron Radiation Telescope Jim Alexander11:35-11:55 Design and Fabrication of a Radiation-Hard
500 MHz digitizer K K Gan11:55-12:15 Nanometer resolution Beam Position Monitors Marc Ross12:15-12:35 Nanometer BPM supports and movers Jeff Gronberg
Tuesday, July 15, 1:50-3:50 p.m.1:50-2:10 TTF data acquisition Tim Wilksen 2:10-2:30 Beam size diagnostics using diffraction radiation Bibo Feng2:30-2:50 A0 coherent radiation diagnostics Court Bohn
What are the uses of nanometer-resolution BPMs?
– Measure beam position with accuracy better than support stability• Use the beam as a mechanical ‘device’ to prove active stabilization?
– Measure beam parameters other than position• Many applications in beam manipulation
• RF BPM ideal
• 3 Balakin BPMs installed at ATF.
• Started to study performance.
Accelerator Working Group: Systems and InstrumentationAccelerator Working Group: Systems and Instrumentation
Monday, July 14, 10:55-12:5510:55-11:15 Accelerator Instrumentation RD Marc Ross11:15-11:35 Prototype Synchrotron Radiation Telescope Jim Alexander11:35-11:55 Design and Fabrication of a Radiation-Hard
500 MHz digitizer K K Gan11:55-12:15 Nanometer resolution Beam Position Monitors Marc Ross12:15-12:35 Nanometer BPM supports and movers Jeff Gronberg
Tuesday, July 15, 1:50-3:50 p.m.1:50-2:10 TTF data acquisition Tim Wilksen2:10-2:30 Beam size diagnostics using diffraction radiation Bibo Feng2:30-2:50 A0 coherent radiation diagnostics Court Bohn
• To demonstrate nanometer resolution the BPMs must be stable at the nanometer level with respect to one another.
• Designed 3 hexapod-structure to hold and align BPMs.
• Mechanical modes of the structure should be above 200 Hz, where they do not harm.
• Vibration simulations are done, alignment frame is under construction.
• Beam test at ATF in October 2003.
Accelerator Working Group: Systems and InstrumentationAccelerator Working Group: Systems and Instrumentation
Monday, July 14, 10:55-12:5510:55-11:15 Accelerator Instrumentation RD Marc Ross11:15-11:35 Prototype Synchrotron Radiation Telescope Jim Alexander11:35-11:55 Design and Fabrication of a Radiation-Hard
500 MHz digitizer K K Gan11:55-12:15 Nanometer resolution Beam Position Monitors Marc Ross12:15-12:35 Nanometer BPM supports and movers Jeff Gronberg
Tuesday, July 15, 1:50-3:50 p.m.1:50-2:10 TTF data acquisition Tim Wilksen2:10-2:30 Beam size diagnostics using diffraction radiation Bibo Feng2:30-2:50 A0 coherent radiation diagnostics Court Bohn
•Cornell, DESY and OSU initiated a joined project to design and develop a TTF 2 data acquisition by using collaboration technologies as an example for a possible future GAN scenario.
• Built on top of the DOOCS accelerator control system.
•Development of collaborative tools.
• First application: TTF2 FEL (2004). 50 to 100 GB/day.
Accelerator Working Group: Systems and InstrumentationAccelerator Working Group: Systems and Instrumentation
Monday, July 14, 10:55-12:5510:55-11:15 Accelerator Instrumentation RD Marc Ross11:15-11:35 Prototype Synchrotron Radiation Telescope Jim Alexander11:35-11:55 Design and Fabrication of a Radiation-Hard
500 MHz digitizer K K Gan11:55-12:15 Nanometer resolution Beam Position Monitors Marc Ross12:15-12:35 Nanometer BPM supports and movers Jeff Gronberg
Tuesday, July 15, 1:50-3:50 p.m.1:50-2:10 TTF data acquisition Tim Wilksen2:10-2:30 Beam size diagnostics using diffraction radiation Bibo Feng2:30-2:50 A0 coherent radiation diagnostics Court Bohn
Why use diffraction radiation for beam diagnostic?
• Non-invasive: Diffraction radiation through a slit. • Beam size diagnostics: longitudinal and transverse• Beam position monitor: radiation intensity vs. beam position• More beam information: beam energy and emittance
xy
z e-
a
Status and Plans at Vanderbilt FEL:
•Studies of diffraction radiation
•Designed and built a interferometer
•Future:•Radiator: vacuum chamber and slit actuator
•Longitudinal bunch length experiments
•Measurement of DR angular distribution
•Transverse beam dimension experiments
Accelerator Working Group: Systems and InstrumentationAccelerator Working Group: Systems and Instrumentation
Monday, July 14, 10:55-12:5510:55-11:15 Accelerator Instrumentation RD Marc Ross11:15-11:35 Prototype Synchrotron Radiation Telescope Jim Alexander11:35-11:55 Design and Fabrication of a Radiation-Hard
500 MHz digitizer K K Gan11:55-12:15 Nanometer resolution Beam Position Monitors Marc Ross12:15-12:35 Nanometer BPM supports and movers Jeff Gronberg
Tuesday, July 15, 1:50-3:50 p.m.1:50-2:10 TTF data acquisition Tim Wilksen2:10-2:30 Beam size diagnostics using diffraction
radiation Bibo Feng2:30-2:50 A0 coherent radiation diagnostics Court Bohn
• Coherent radiation studies at A0 for beam diagnostic
• Built a new, compact Michelson interferometer
• Future goal: single shot measurement (with Fresnel mirror, no moving parts)
Thank you Speakers!
This was fun!