MCTF

C. Johnstone All Exp. Meeting 14 Mar 2011 1

First Beam to Muon Test Area

Description and commissioning of beam to MTA Experimental Hall

C. Johnstone, T. Kobilarc, D. Newhart – commissioning team

Special thanks to AD support departments

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Purpose: MuCool Test Area and Beamline

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• A new experimental area, the Muon Test Area,(2003) has been constructed to develop, test, and verify muon ionization apparatus using the 400-MeV proton beam from the Fermilab Linac

• Since muon facilities involve the capture, collection and cooling of ~1013 muons at a repetition conclusive tests require

• ~1013 protons/pulse (full Linac beam)

• The beamline designed for MTA experiments included specialized insertions for linac beam diagnostics and beam measurements, greatly enhancing the functionality of the beamline.

• Installation of the beamline was complete fall, 2008.

• As such it represents the only facility in which experiments have direct access to a primary beam

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Background/Recent History, MTA Beamline

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• Original proposal 1995– Re-proposed for MuCool Test Area

• Large-aperture (LANL) magnets– 12” beam-size acceptance for cooling tests

– Re-designed for dual purpose• MTA beamline

– Re-use existing resources

» Modest 2” beam sizes

• Linac beam diagnostic line– Transverse emittance measurement

» Phase space tomography (w/o dispersion)

– Momentum spread measure (high dispersion)

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As-built MTA Beamline, Nov., 2007

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You are Here

To MTA

Beamline installation: F. Garcia

March, 2007

Nov, 2007

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Extraction from Linac

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• Pulsed C magnet – capable of 15 Hz Linac “pulse” selection– Entire Linac pulse is extracted

– low loss operation

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Emittance Measurement section

• Takes advantage of

shield wall

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10 m straight between quads3 MW profile monitors for tomographydisp suppressed straight

3 profiles

MTA hall

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MTA beam event

• Initial startup – – Reuquired dedicated studies

(HEP beam)– Booster beam event

• Interim configuration -– Parasitic to HEP– Commandeer Linac Study event

• Final configuration– Dedicated MTA event TLG– “single-pulse” extraction– Parasitic to HEP

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MTA Beam to 1st Beamstop

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1st beam stop

MTA exp hall

Beamstop cave Beampipe exit

• Initial beam: linac enclosure only– 1st beam stop with present

hatch shielding

• Beam to Exp Hall– Additional shielding primarily:

• Hatch, penetrations, rollup door

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MTA Issues 2009-2010

• UVB01– Air-core, old Booster corrector, used as

vertical bend in MTA– Large, unacceptable steering effect in 400-MeV line

• UQ01:– Used as combined-function to achieve 1.5 degree slope of Linac access ramp– Smaller, millimeter impact on Booster transfer line

• Stray field shielding required

• UHB03– Power supply borrowed from TEL group was reclaimed– 150 kW supply from Switchyard identified as

new MTA supply• MW1-4

– Not Working

UVB01

UQ01

MTA line

Booster injection line

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MTA/Linac shutdown work/beam tests

• Jan 2009– Installation of permanent magnet

• Fall, 2009– Switchyard 150 kW supply reworked, installed in

Linac basement for MTA (connected to L3 switchgear)

• Jan 2010– Alignment of permanent magnet– Re-alignment of UQ01 (centered rather than

offset)• Feb 2010

– 1st beam test after PM installation/CRD PS replacement

– Minimal beam observed (1/4 of extracted intensity) on UTR01; no beam on BPM#2

– High losses on UQ02– C-magnet/Linac steering did not improve

transmission– No beam observed on UMW1 @exit of linac– High losses in Linac absorber area/toroid– Possible cause: alignment of downstream

elements after PM installation still pending

UTR01

ULMQ02

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Beam Stop: Critical Device

Shield wall

Linac Extraction Point

The layout of the MTA beamline upstream of shield wall.

UTR01

BPM#7

ULMQ02

UHB03A

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MTA/Linac shutdown work/beam tests continued

• April 2010– Re-alignment of rest of remaining

beamline from permanent magnet to UVB02

– PM inspected and polarity checked– Beam test

• Little improvement in transmission to UTR01• Still high losses in Linac diagnostic line• No beam observed on 1st MW• Steering out of linac made no improvement• Turning off UHB03 no impact on losses!• Last pulse, closed gate valve to confirm valve

status and polarity of “C” magnets• Positive beam profile now on UMW1!

– Subsequent vacuum tests indicate gate valve properly wired and reported

– UMW1 wire scanner not able to detect negative (H-) signals

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MTA/Linac shutdown work/beam tests continued

• April 2010– Scanner upgraded– UMW1 temp hooked to UMW2– UMW1 H- beam now observed– No beam on UMW2– UHB03 polarity reversed

• Nothing impacts or increases transmission

• May 2010– Another beam test– Loss monitors plotted at right– Linac steering tests

• no impact on transmission or linac losses in diagnostic line

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MTA/Linac Shutdown work/beam tests

• July 2010– Investigation of permanent magnet field

• 1.4 kG verified with Hall probe

– UHB03A check• Highly activated beampipe downstream of UHB03 on east side indicating beam exiting at

this location• Found ¼ field strength with Hall probe based on current read-out• Tap was incorrect downstream

of current monitor; fixed• This is the transmission problem

– Beam test• Full transmission to UTR01• BPMs indicate primary beam to

Beam stop• Only allowed 10 pulses • Shielding assessment and DOE

approval required

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Commissioning to 1st Beam Stop

• Nov., 2010– Clean profiles recorded to Beam stop

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Commissioning the MTA Beamline

• Two modes– Emittance (linac diagnostics)

• Beam stops in Emittance Absorber• Allowed rate 10 pulses/min @full Linac intensity

– Experimental• Beam is fully absorbed in experimental apparatus or• Beam is cleanly transported to high-intensity beam absorber• Allowed rate 1 pulse/minute @full Linac intensity

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The MTA beamline downstream of shield wall.

Final beam absorber

Emittance beam absorber

Shield Wall

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• Implies beam to Emittance Absorber only at entrance to hall• Feb 28, 2011, 1st pulse; primary beam enters Experimental Hall

through shield wall• Takes out the rad detector set to 200 mr/hr in hall• More work on diagnostics was required• Present - essentially 100% transmission to hall

Commissioning the MTA Beamline in Emittance Mode

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Summary

• MTA beamline commissioned in Emittance Mode with 100% transmission through shield wall.

• Next: Final operational tunes• Linac Studies

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