HQ01e protection heater tests

Summary

Aug 02, 2012

T. Salmi

HQ PH

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OL ILWidth [cm] 1.1 1.03Area [cm2] 243 217R strip [Ω] (@ 2.2 K) 4.12 4.38

Outer layer (OL)

Inner layer (IL)

TraceStainless steel: 25.4 μm (1 mil), Kapton: 25.4 μm (with glue ~45 μm)

PH study overview

Parameters• Temperature [K]: 4.4, 1.9• Imag [kA]: 5, 8, 11, 14• IL, OL (Coil 9)

PH delayTime

Volta

ge

VPH ≈ 230 V Pw0 ≈ 50 W/cm2 (OL) Pw0 ≈ 50 W/cm2 (IL)

τ = RC ≈ 40 ms

Quenchdetected

Voltage tap signal

Procedure• Imag constant • 1 PH strip fired• Delay to quench onset measured

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HQ01e: PH delays

4HQ01e at CERN: Pw0 = 50 W/cm2, tau 40 ms: Iss = 17.3 kA @ 4.4 K; 19.1 kA @ 1.9 K

Innerlayer

Outerlayer

• PH delay scales with Iss Almost independent of temperature

• OL quench faster than IL• EXCEPTION: 4.4 K & 14 kA: IL

quench faster (but slower propagation)

HQ01e: 25.4 μm Kapton

HQ01e vs. HQM01 and HQM04:Outer layer

• HQ01e: 25.4 μm Kapton

• HQM01: 50.8 μm Kapton (+ 100 %) PH delay + 20 to 50 %

• HQM04: 76.2 μm Kapton (+ 200 %) PH delay + 60 to 150 %

• Note:In HQM01 and HQM04 this is a typical

result using tau = 46 ms.Using tau = 23 ms, if Imag = 5 kA, the

quench in HQM04 is faster than inHQM01.

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HQ01e at CERN: Pw0 = 50 W/cm2, tau 40 ms: Iss = 17.3 kA @ 4.4 K; 19.1 kA @ 1.9 KHQM04 at FNAL: Pw0 = 45 W/cm2, tau 46 ms: Iss = 16.2 kA @ 4.6 K; 18.2 kA @ 2.2 KHQM01 at FNAL: Pw0 = 47 W/cm2, tau 46 ms: Iss = 17.0 kA @ 4.6 K

VPH = 230 V

HQM04HQM01

HQ01e

HQ01e vs. HQM04: Inner layer

HQ01e at CERN: Pw0 = 55 W/cm2, tau 40 ms: Iss = 17.3 kA @ 4.4 K; 19.1 kA @ 1.9 KHQM04 at FNAL: Pw0 = 49 W/cm2, tau 46 ms: Iss = 16.2 kA @ 4.6 K; 18.2 kA @ 2.2 K 6

• NO difference for Imag < 12 kA!

• Imag > 12 kA: Longer delay in HQM04

• Superfluid• Cooling for coil• Contact with coil

VPH = 230 V

HQ01e

HQM04 HQ01e: 25.4 μm KaptonHQM04: 76.2 μm Kapton

Summary

• HQ01e: 25.4 μm Kapton between SS and coil

• HQ01e: PH delays measured using VPH = 230 V, Pw0 = 50 W/cm2, tau = 40 ms

• PH delays at 81 % of Iss: 7 ms (OL) and 6 ms (IL) (+/- 1 ms)

• PH delay seems almost independent of operating temperature

• Imag <= 12 kA: IL quench slower than OL– Imag = 14 kA: IL quench faster– Need more data at high current to confirm

• Comparison with coils tested in the mirror structure:HQM01: + 100 % Kapton (50.8 μm) OL: PH delay +20 … 50 % (IL not tested in HQM01)

HQM04: + 200 % Kapton (76.2 μm) OL: PH delay +60 … 150 % (OL) IL: No difference for Imag < 12 kA

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Thank you!

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PH delay definition – HQ01e

Quenchonset

Example: 11 kA – fired 9B02 – 4.4 K (qhi10)

At 11 kA and 14 kA quench signals are quite clear.Quench onset defined when a segment voltage starts the rise to quench. 9

HQ voltage tap locations

The distances between the taps (mm)Inner layerOuter layer

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9A02 – 4.4. K – 14 kA

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9A05-04 quenches (higher field).In other IL tests, 9A04-03 quench (More turns covered by PH).

9A02 – 4.4. K – 14 kA

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9B02 – 4.4. K – 14 kA

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9B04-05 quenches (typical).Slower first quench onset, but faster quench detection than in IL.