Linac Test AreaInstrumentation Update

M. Haney, D. Errede,Z. Conway

University of Illinois at Urbana-Champaign

14 June 2002

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Instrumentation

• Need safe solution for instrumenting the LH2 absorber in the LTA

• Prudent to accommodate MICEand European safety considerations– i.e. do it right the first time…

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Primary Objective - Safety

• Intrinsic safety, if possible– Less than 1 watt (per channel?)– Good idea for Fermi; required for Europe

• Gas-purged enclosure, if necessary– 19” rack, 40U tall

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Signals inside (the cryostat)

• 12 (cryo) temperatures– readout via GPIB + LabView (PC)

• 25(ish) 4-wire bolometry strips• Multiple fibers

– FISO strain gages– Laser occlusion?– Simple spark detectors

• (light pipe to photodiode)

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(more) Signals inside

• USB (4 wires, and shield) for CCD camera– via PC

• Piezo vibration sensor– via (16 chan/12 bit) ADC and LabView (PC)

• Local (64 chan/16 bit) IRM channels– via “LabView” (see last slide)

• MICE channels (?)– placeholder for the future…

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Signals outside

• Many voltages, currents, temperatures, pressures– magnets, beam position monitors, etc.

• Most available from ACNET or local IRM– via “LabView” (see last slide)

• or Cyro-PLC– and Intellution

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Two Possibilities (1)

• Intrinsically safe

UPS

PC w/32 chan ADC

FISO

Cryo(temp)

IRM

Barrier(s)

network

ACNET

Sealed Conduit(s)

Intrinsically safe signal conditionersand transmitters

power

Hazard Safe

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Two Possibilities (2)

• Gas-purged box

UPS

PC w/32 chan ADC

FISO

Cryo(temp)

IRM

Barrier(s)

network

ACNET

Sealed Conduit(s)

power

Hazard Safe

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(basic) Barrier

Power +Signal

Return

Ground

“safe circuit”

fuse

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This Summer – Z. Conway

• LabView interface– GPIB– ADC– IRM

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Open Issues

• Local signal condition vs Purged box– Common mode concerns (noise from magnets)

• Especially surge currents on start/stop

– Long wires!

• 2-wire vs 4-wire solutions– Shielding and noise sensitivity in general– Cable plant size concern

• (already 200+ wires, not including shielding)

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Open Issues (2)

• LabView vs C – to read ACNET data

(mostly, IRMs outside of the experiment)

• Remote control of PC– Citrix ICA, PCAnyWhere, etc.– LabView web-remote instrumentation– KVM?