ATLAS Intensity and Efficiency Upgrade ATLAS USERS MEETING Speaker: Mike Kelly Physics Division May 15, 2014.

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

2.

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)

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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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