APA Commissioning Results Andrzej Szelc & Serhan Tufanli - - PowerPoint PPT Presentation

APA Commissioning Results

Andrzej Szelc & Serhan Tufanli

Introduction

• What we measured

○ Side A ○ Side B

• Notes/Observations on method(s)

○ What we can and cannot measure ○ Comparison + Calibration

• Measurements on Side A

○ First observations + Rechecks

• Measurements on Side B

○ Selection of wires + results

• Conclusions

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What we measured: Side A

• Measured 112 wires in total ( 43 G-plane, 14 X-plane, 27 V-plane, 28 U

plane).

• First measurements to see how quick we can do the tension measurements.
• After first look at data, did a few extra cross-checks.

○ Measured a few G-plane wires in region 2.

• *Did not* pay much attention to mapping or selecting outliers - focus on

understanding the system and method.

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What we measured: Side B

• 188 Total wires (69 in plane G, 51 in plane U, 37

in plane V, 31 in plane X).

• Relatively thorough measurement - measure

wires around board boundaries (G-Plane) + selected outliers.

○ Result is a sample of random wires and outliers.

• Came up with list prepared but improvised in

regions.

○ Much faster to do adjacent wires than search for a single wire according to mapping.

• Paid attention to mapping (as much as possible).
• Limited to Region 1.

Region 1

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Observations/notes on method(s)

• We used the laser tensioning device in two modes:

○ Connected to a guitar amplifier + tuner app on smartphone (consistent with method used at PSL)

○

Connected to laptop with LabView DAQ: calculates FFT and selects peaks, calibrated at Manchester.

• Amplifier + Tuner is really helpful in figuring out the

mapping.

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Tuner vs LabView cross-calibration

• Plot of tension of same wires

between labview and the tuner.

• LabView setup has been calibrated

in MCR, see difference of O(1Hz) around 60 Hz (in tune with our

• bservations)

Estimated error of our measurement is O(1Hz), which means max 3% (depending wire length) systematics in tension of wires.

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Observations/notes on methods and APA geometry constraints

• Mapping G and X wire plane wires is almost

impossible outside of regions 1 and 5.

• In each region there are 2 possible placements
• f tensioning bar.
• In region 5, lowest and middle positions are not

usable due to bolts tethering the APA to ground.

• In region 1 the middle (and top?) position is not

usable due to absence of M1 holes.

• Due to APA geometry, a set of wires in U and V

planes are not possible to test (short wires).

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First Measurements on Side A (plane X)

• All wires measured were in the higher half of spectrum.
• “Wire-by-wire” comparison indicates a systematic shift of 10% (note that

mapping might not be exactly precise)

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First Measurements on Side A (plane V)

• Tension looks visibly shifted down. “Wire-by-wire” comparison suggests a

drop of 10-15% in tension.* *Note that here mapping here is not precise for all wires. Although, in these cases, the wires are same length, so general

tension comments apply in region.

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First Measurements on Side A (plane U)

• U-Plane wires seem to be in the right ball park.
• Wire-by-wire comparison seems to show a small rise in tension (0-10%).

○ Mapping not perfect, so side B should be more precise.

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First Measurements on Side A (plane G)

• G-Plane tension seems systematically higher (15-20%).

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Additional measurements on Side A (plane G, Region 2)

• Region 2 seems to be less over-tensioned than Region 1

○ (small sample size, though)

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Measurement on Side B - Plane X

• 31 wires were measured

○ Outlier wires: ■ Mean Tension-2.5*RMS > tension of the wire OR MeanTension+2.5*RMS < tension of the wire OR ■ Tension of the wire > 5.3N ○ Random wires from the end and beginning of boards

• Tension is 7% higher than the PSL measurements

with 5% RMS

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Measurement on Side B - Plane V

• 37 wires were measured

○ Outlier wires:

■ Mean Tension-2.5*RMS > tension of the wire OR Mean Tension+2.5*RMS < tension of the wire OR ■ Tension of the wire <4N OR tension of the wire>5.9N AND ■ Wirelength>600

○ Random wires from the end and beginning of boards

• Tension is 14% less than the PSL measurements with

2% RMS

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Measurement on Side B - Plane U

• 45 wires were measured

○ Outlier wires:

■ Mean Tension-2.5*RMS > tension of the wire OR Mean Tension+2.5*RMS < tension of the wire OR ■ Tension of the wire <4N OR tension of the wire>6N AND ■ Wirelength>600

○ Random wires from the end and beginning of boards

• Tension is 5% more than the PSL measurements with

~1% RMS

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Measurement on Side B - Plane G

• 69 wires were measured

○ Outlier wires: ■ Mean Tension-2.5*RMS > tension of the wire OR MeanTension+2.5*RMS < tension of the wire OR ■ Tension of the wire > 5.5N ○ Random wires from the end and beginning of boards

• Tension is 15% higher than the PSL measurements

with 2% RMS

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Possible reasons for the measured difference

• Different APA orientation during the tension

measurements

○ Horizontal at PSL ○ Vertical at CERN

• Systematics due to hardware and measurement method

○ Hardware: Different amplification hardware between PSL and CERN ○ Method: Constraining wires with clips on combs

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Conclusions

• We re-measured the tension of 300 wires at CERN
• We observed

○ 7% increase in tension for X layer wires ○ 14% decrease in tension of the V layer wires ○ 5% increase in the tension of the U layer wires ○ 15% increase in the tension of G layer wires

• APA orientation during the tension measurements might be the biggest

reason

○ Detailed FEA analysis and engineering is needed if we would like to understand all the details

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