atlas intensity and efficiency upgrade atlas users meeting speaker: mike kelly physics division may...
TRANSCRIPT
ATLAS Intensity and Efficiency Upgrade
ATLAS USERS MEETING
Speaker: Mike KellyPhysics Division
May 15, 2014
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CARIBU
4. Split-ring cryomodules
109 MHz Energy Upgrade cryomodule
2013
2009
2013
The Present ATLAS Accelerator Cryomodules8 Cryomodules, 47 SC Accelerating Cavities
1992
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1. 60 MHz RFQ
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2. PII Cryomodules
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3. 72 MHz Module
5.5. 109 MHz Module
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Clean Assembly (left) and Cryogenics Assembly (right) for ATLAS Intensity Upgrade Cryomodule (2013)
Jan. 2013
June 2013
Clean room assembly (south side of beamline)
Assembly stand (north side of beamline)
Charged Particle Acceleration in a 2-gap Accelerating Cavity
z
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q
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RF Surface: (Simplified) Niobium Surface, Tc=9.2 Kelvin
Superconductivity ~40 nm
Electropolishing System for Low-beta Cavities
A unique ANL technical capability to electropolish cavities as the final step in fabrication
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Subcomponents: RF Couplers4 kW RF Power
ATLAS 4 kW Couplers
Issue of Maintaining the Clean Vacuum Space (a.k.a. Protection from the ATLAS Users)
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80 Kelvin ~1/2 meter long liquid nitrogen cooled cold traps installed at the entrance and exit for clean cryomodules
Volatiles, water, particulates adsorb to the surface of a 2.5” cm diameter copper tube
Gate valves at the entrance and exit of the cryomodule are interlocked to cold trap ion gauges
A fast acting valve (~10 mS) will isolate experimental areas from the accelerator in the event of a vacuum accident
Cold trap
Fast Valve
RGA
Cryomodule exit valve
The First Beam Delivered with the 72 MHz Intensity Upgrade Cryomodule
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First beam to experiment20Ne6+ on Feb. 18, 2014 (Ave. Cavity Voltage 2 MV/cavity, Ave. Power per Cavity 1.3 Watts)
Also of note, all cavities stable with respect to quench with EACC>12 MV/m, average value for field emission onset, EACC~9 MV/m (EPEAK~45 MV/m)
Testing at Liquid Helium Temperatures: Q versus E (Most Commonly Used Figure of Merit)
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Present Operations2.5 MV/cavity
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Context and Impact: SARAF Proton/Deuteron Accelerator
In operation since 2009
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Context and Impact: MSU Re-Accelerator (ReA3)
C
Planned for May 2014
In operation since 2011
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Context and Impact: ISAC-II Heavy-ion Linac, 6 Cryomodules
Commissioned 2006-2010
Peter Ostroumov – Accelerator R&D LeaderZachary Conway – Cryomodule assemblyMichael Kelly – Clean assembly, cavity testingScott Gerbick – Electropolishing design, up-to-air systemTom Reid – Chemistry operationsRyan Murphy – High-pressure rinsing, single-cavity assemblyMark Kedzie – Vacuum systems, cryomodule assemblySang-hoon Kim – Alignment, diagnosticsGary Zinkann – SRF Cavity TestingBrahim Mustapha – Simulation support (e.g. cavity tuning)Sergey Kutsaev – Power simulations & qualification
Also Acknowledge Efforts ofSteve MacDonald – Cryogenics upgradeSergey Sharmentov – New RF Control System
Team for ANL SRF Cavity/Cryomodule Work
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