![](media/image1.png){width="1.0in" height="1.0in"}

8/22/07

TD-07-022

LARP Note, Aug 07

LARP TQS02a Test Summary

Content:

1\. Introduction 2

2\. Quench history 2

3\. Quenches at temperature between 1.9 and 4.5K 10

4\. Ramp rate dependence 11

5\. Protection Heater study 12

6\. Spot Heater study 14

7\. Strain gauge results 15

8\. Quench antenna data 25

9\. RRR measurement 26

10\. Quench origin location 29

11\. Magnetic measurement 31

1\. Introduction

TQS02a is a 1m long quadrupole model assembled at LBNL as part of the
LARP program. TQS02a uses the same support structure of TQS01 with new
coils (made of 54/61 RRP strand). This report documents the test of
TQS02a performed at Fermilab in the Vertical Magnet Test Facility (VMTF)
at 4.5 and 1.9 K. According to a request by LBNL a slow cool down
(maintaining ∆T\<50 K across the magnet) was executed, starting on the
early morning of June 2 to the end of the day on June 3, during which
strain gauges and coil segment resistances were continuously monitored.
Magnet test started on June 4 and lasted until June 21. The VSDS
(Voltage Spike Detection System) was used during the whole test. A
detailed analysis of the data recorded by the VSDS is presented in
\[1\].

2\. Quench History

The cold test program started at 4.5 K with cold magnetic measurement
followed by magnet training at 20 A/s ramp rate. At the beginning of the
training the quench detection threshold was set to 500 mV. A series of
trips induced by voltage spikes (flux jumps) caused the increase of the
detection threshold to 700 mV, then to 1.5 V and finally to 3 V.
Subsequently the threshold was lowered to 2V (because of concerns about
possible high MIITs), but had to be increased again to 3 V to avoid
trips induced by flux jumps. The first quench occurred at 9902 A. During
training at 4.5 K, with 3 V detection threshold, two trips induced by
very high voltage spikes occurred at 1737 and 1949 A.

After a series of quenches (from #8 to #16) in coil 20, with quench
current varying between 11.1 and 11.8 kA, the quench onset moved to coil
21. Quench #18 started in the so called "pizza box" (a G10 structure
containing all coil-to-coil junctions, located on the top of the lead
end) close to the splice between coil 20 and coil 21 NbTi leads. This
quench occurred at 12.274 A, the highest current reached at 4.5K during
the whole test. This quench developed 10 MIITs because of the high
quench detection threshold, and the slow propagation. However it didn't
cause any damage to the NbTi cables. At lower temperatures TQS02 reached
two times higher currents without quenhes in the "pizza box". The
following quenches showed a fallback (11.4 kA in quench #19), a quick
recovery, and a plateau with an average of 12123 A and a slightly
negative slop of -22 A/quench.

Subsequently ramp rate studies at 4.5 K were performed, and then the
magnet was cooled down to 1.9 K. Tests with 20 A/s ramp rate at 1.9K
(from #34 to #45) showed the quench current fluctuating in the range
11.25 kA -- 11.95 kA with the exception of quench \# 42 that reached
12.39 kA (this quench occurred after magnetic measurement at 1.9K
performed after a partial magnet warm-up). All quenches at 1.9K started
in coil 21. Quenches from #46 to #48 were performed during magnet
warm-up. Ramp #47 started with 40 A/s up to 10 kA, and then 10 A/s. This
ramp reached the highest quench current of the whole test (12,467 A). A
final series of quenches at 4.5 K with 20 A/s ramp showed a plateau of
11930 A +/- 10A.

![](media/image2.wmf){width="5.252777777777778in"
height="4.102083333333334in"}

Figure 2.1. TQS02a quench history.

**TQS02a Quench History table with comments**

  -------------------------------- -------- ----------- --------- --------------- ----------- ------- ------- ----------------------
  **File**                         **\#**   **Current   **dI/dt   **t~quench~**   **MIITs**   **Mag   **Mag   **Comments**
                                            (A)**       (A/s)**                               Temp\   Temp\   
                                                                                              Bot L   Top L   
                                                                                              (K)**   (K)**   

  tqs02a.Quench.070604130438.013            1002        0         0.0017          0.17        4.424   4.421   darryl couldn\'t
                                                                                                              balance cu-i aqd, so
                                                                                                              the techs will have to
                                                                                                              look at this.

  tqs02a.Quench.070604153926.160            1327        50        -0.4000         0.88        4.429   4.427   dqd_coil detected a
                                                                                                              signal - perhaps a
                                                                                                              spike-induced trip? we
                                                                                                              were ramping up at
                                                                                                              50A/s to perform
                                                                                                              heater-induced quench.

  tqs02a.Quench.070604155955.441            1727        20        -0.0027         0.30        4.426   4.422   20 A /s ramp to 5000A
                                                                                                              to perform
                                                                                                              heater-induced quench,
                                                                                                              with threshold raised
                                                                                                              to 1.5V. DQD coil
                                                                                                              detection.

  tqs02a.Quench.070604162531.931            5003        20        -0.0238         2.55        4.427   4.425   HFU_1 fired at 300V to
                                                                                                              induce a quench and
                                                                                                              capture data at 5000A.
                                                                                                              We will check signals,
                                                                                                              which GV and JH
                                                                                                              conduct magnetic
                                                                                                              measurements. HFU_2
                                                                                                              was in protection mode
                                                                                                              at 100V, HFU_3 spot
                                                                                                              heater was \"offline\"
                                                                                                              but should have fired
                                                                                                              from \_2 contact
                                                                                                              closure, at 12V.

  tqs02a.Quench.070605100858.753            1705        20        -0.0218         0.34        4.441   4.442   2V threshold appears
                                                                                                              to be unworkable\...
                                                                                                              we tripped off on a
                                                                                                              voltage spike similar
                                                                                                              to yesterday\'s large
                                                                                                              spike at 1750A.

  tqs02a.Quench.070605144544.801            8014        20        -0.0434         5.64        4.430   4.426   spot heaters in series
                                                                                                              at 9.6mF, 3.5Ohms
                                                                                                              resistance total hfu
                                                                                                              voltage 30V no dump
                                                                                                              delay; protection
                                                                                                              heaters at 400V, no
                                                                                                              p-heater delay

  tqs02a.Quench.070605155126.832            8009        20        -0.0357         5.07        4.428   4.432   the first test at 30V
                                                                                                              induced a quench only
                                                                                                              in coil 23. So we
                                                                                                              raised the voltage to
                                                                                                              see if we could
                                                                                                              initiate quenches in
                                                                                                              all 4 coils.

  tqs02a.Quench.070605162403.186            8006        20        -0.0365         5.12        4.432   4.433   raised the voltage
                                                                                                              from 50 to 70 V, fired
                                                                                                              spot heaters to induce
                                                                                                              quenches, hoping all
                                                                                                              coils will develop
                                                                                                              voltage.

  tqs02a.Quench.070605183235.446            5004        20        -0.0325         2.24        4.433   4.430   repeated the
                                                                                                              heater-induced quench
                                                                                                              at 5000A, but with
                                                                                                              hfu_2 triggered at
                                                                                                              400V; hfu_1 in
                                                                                                              protection mode at
                                                                                                              400V; hfu_3
                                                                                                              simultaneously
                                                                                                              triggered at 70V.

  tqs02a.Quench.070605184714.684   1        9906        20        -0.0148         4.88        4.439   4.436   protection heaters at
                                                                                                              400V, no delay dump
                                                                                                              1ms delay spot heater
                                                                                                              fired at detection,
                                                                                                              70V.

  tqs02a.Quench.070606094913.966   2        10326       20        -0.0105         4.69        4.442   4.437   quenched at 10321A,
                                                                                                              ramp rate 20A/s,
                                                                                                              T=4.45K. HFU3 was off.

  tqs02a.Quench.070606102106.918            1732        20        -0.0192         0.29        4.443   4.441   trip at 1700 A, ramp =
                                                                                                              20 A/s, T = 4.5K

  tqs02a.Quench.070606111444.461   3        11165       20        -0.0106         5.23        4.435   4.434   Ramp 4, rate 20 A/s, I
                                                                                                              = 11161 A, T = 4.5 K
                                                                                                              dump 3ms, PH 300V 7

  tqs02a.Quench.070606115518.721   4        11441       20        -0.0085         5.07        4.436   4.436   ramp 5, I = 11440 A,
                                                                                                              rate = 20 A/s, T = 4.5
                                                                                                              K

  tqs02a.Quench.070606123347.247   5        11578       20        -0.0108         5.43        4.437   4.434   Ramp 6, I = 11575 A,
                                                                                                              ramp = 20 A/s, T = 4.5
                                                                                                              K

  tqs02a.Quench.070606140258.865   6        10634       20        -0.0155         5.55        4.430   4.427   VSDS system appears to
                                                                                                              be crashed, so we did
                                                                                                              not get spike data.

  tqs02a.Quench.070606144702.183   7        11642       20        -0.0109         5.47        4.437   4.435   Ramp 8, I = 11637 A,
                                                                                                              rate = 20 A/s, T = 4.5
                                                                                                              Kto

  tqs02a.Quench.070606152746.043   8        11602       20        -0.0070         4.90        4.434   4.435   quench at 11599.2A,
                                                                                                              ramp rate 20A/s,
                                                                                                              T=4.45K. H n\` nx

  tqs02a.Quench.070606155359.065   9        11127       20        -0.0120         5.39        4.454   4.454   ramp 10, I = 11126 A,
                                                                                                              rate = 20 A/s, T =
                                                                                                              4.5K

  tqs02a.Quench.070606162133.230   10       11848       20        -0.0073         4.98        4.448   4.444   quench at 11845.6A
                                                                                                              ramp rate 20A/s
                                                                                                              T=4.45K

  tqs02a.Quench.070606164135.111            1945        20        -0.0122         0.33        4.450   4.448   tripped at 1949A, ramp
                                                                                                              rate 20A/s. T=4.45K.

  tqs02a.Quench.070606170223.671   11       11499       20        -0.0115         5.48        4.440   4.436   Ramp 13, I = 11495 A,
                                                                                                              rate = 20 A/s, T =
                                                                                                              4.5K

  tqs02a.Quench.070606173608.118   12       11706       20        -0.0053         4.66        4.446   4.445   Ramp 14, I = 11700 A,
                                                                                                              rate 20 A/s, T = 4.5K
                                                                                                              ƒ÷

  tqs02a.Quench.070606180247.881   13       11521       20        -0.0063         4.81        4.452   4.451   ramp 15, I = 11515,
                                                                                                              rate = 20 A/s, T =
                                                                                                              4.5K

  tqs02a.Quench.070606183249.640   14       11700       20        -0.0050         4.60        4.453   4.450   ramp 16, I = 11696 A,
                                                                                                              rate = 20 A/s, T =
                                                                                                              4.5K

  tqs02a.Quench.070606190519.154   15       11808       20        -0.0048         5.24        4.454   4.450   Ramp 17, I = 11802 A,
                                                                                                              rate = 20 A/s, T =
                                                                                                              4.5K

  tqs02a.Quench.070606193546.194   16       11712       20        -0.0046         5.20        4.457   4.455   Ramp 18, I = 11710 A,
                                                                                                              rate 20 A/s, T = 4.5 K

  tqs02a.Quench.070607085819.744   17       12072       20        -0.0076         6.00        4.467   4.466   ramp 19, I = 12069 A,
                                                                                                              rate = 20 A/s, T = 4.5
                                                                                                              K

  tqs02a.Quench.070607093814.124   18       12274       20        -0.0339         10.07       4.452   4.455   ramp 20, I = 12269 A,
                                                                                                              rate = 20 A/s, T =
                                                                                                              4.5K

  tqs02a.Quench.070607104128.088   19       11380       20        -0.0098         4.92        4.432   4.433   ramp 21, I = 11378 A,
                                                                                                              rate = 20 A/s, T =
                                                                                                              4.5K

  tqs02a.Quench.070607112015.464   20       11974       20        -0.0109         6.38        4.439   4.434   Ramp 22, I = 11970 A,
                                                                                                              rate 20 A/s, T = 4.5K

  tqs02a.Quench.070607114524.375   21       12165       20        -0.0050         5.6         4.472   4.465   Ramp 23, I = 12162 A,
                                                                                                              rate 20 A/s, T = 4.5K

  tqs02a.Quench.070607121514.882   22       12153       20        -0.0052         5.61        4.459   4.457   ramp 24, I = 12146 A,
                                                                                                              rate = 20 A/s, T =
                                                                                                              4.5K

  tqs02a.Quench.070607135538.210   23       12139       20        -0.0055         5.7         4.320   4.383   cool down to 1.9K was
                                                                                                              aborted because Kinney
                                                                                                              pump developed a
                                                                                                              problem, but
                                                                                                              temperature is
                                                                                                              slightly cooler than
                                                                                                              it was earlier.

  tqs02a.Quench.070607163339.026   24       12110       20        -0.0046         5.61        4.410   4.410   several gains were
                                                                                                              changed to prevent
                                                                                                              saturation,
                                                                                                              21B04_12B05,
                                                                                                              21B03_21B04,
                                                                                                              21B05_21B06

  tqs02a.Quench.070607172917.427   25       12074       20        -0.0050         5.88        4.421   4.421   quench at 12070.5A,
                                                                                                              ramp rate 20A/s,
                                                                                                              T=4.42K. Dump delay 18
                                                                                                              msec (was 13 msec)

  tqs02a.Quench.070608101421.572   26       12050       5         -0.0055         5.83        4.429   4.427   Ramp to 11kAmps at
                                                                                                              20Amps/sec then ramp
                                                                                                              to quench at
                                                                                                              5Amps/sece

  tqs02a.Quench.070608110141.397   27       11964       40        -0.0070         6           4.438   4.437   Ramp to quench at
                                                                                                              40A/sec

  tqs02a.Quench.070608112453.473   28       11717       80        -0.0090         6.1         4.442   4.445   quench at 11714.4A,
                                                                                                              ramp rate was 80A/s,
                                                                                                              T=4.45K.

  tqs02a.Quench.070608121122.767   29       12011       10        -0.0056         5.82        4.452   4.446   quench at I=12008A,
                                                                                                              ramp rate = 10A/s,
                                                                                                              T=4.45K.

  tqs02a.Quench.070608140958.401   30       11407       100       -0.0028         4.78        4.426   4.423   ramped at 5A/s to
                                                                                                              7500A, then 100A/s to
                                                                                                              quench (not realizing
                                                                                                              that 5A/s had already
                                                                                                              been done).

  tqs02a.Quench.070609135925.713   31       10217       120       -0.0048         4.68        4.421   4.421   Ramp 33, I = 10217 A,
                                                                                                              rate = 120 A/s, T =
                                                                                                              4.5 K

  tqs02a.Quench.070609143013.717   32       11844       60        -0.0087         6.15        4.429   4.433   Ramp 34, I = 11839 A,
                                                                                                              Rate = 60 A/s, T =
                                                                                                              4.5K

  tqs02a.Quench.070611162130.884   33       11963       5         -0.0046         4.53        4.410   4.408   quench at 11956A, ramp
                                                                                                              rate was 20A/s upto
                                                                                                              10kA and then 5A/s
                                                                                                              till the quench.
                                                                                                              HFU1/2 both were
                                                                                                              charged to 200V, delay
                                                                                                              0ms. Dump delay 1ms.

  tqs02a.Quench.070612140759.260   34       11937       20        -0.0057         4.83        1.853   1.853   heaters at 200V to
                                                                                                              keep noise low. ramp
                                                                                                              rate 20 A/s

  tqs02a.Quench.070612152045.937   35       11252       20        -0.0084         4.93        1.881   1.882   quench current is
                                                                                                              rather low! appears to
                                                                                                              be AQD_COIL

  tqs02a.Quench.070612172710.819   36       11777       20        -0.0063         4.83        1.815   1.813   spike system threshold
                                                                                                              at 150mV. This will be
                                                                                                              the last quench today,
                                                                                                              as the gas storage
                                                                                                              tank pressure is now
                                                                                                              150 psi and we need to
                                                                                                              make liquid.

  tqs02a.Quench.070618140753.334            1516        20        0.0003          0.16        1.818   1.819   We did a manual trip
                                                                                                              in order to check that
                                                                                                              everything is OK after
                                                                                                              the work done
                                                                                                              Friday/Monday.

  tqs02a.Quench.070618143844.917   37       11446       20        -0.0070         4.85        1.820   1.820   quench at 11439A,
                                                                                                              T=1.82K, ramp rate
                                                                                                              20A/s. HFU1/2=200V,
                                                                                                              0ms delay, dump delay
                                                                                                              1ms.

  tqs02a.Quench.070618155056.289   38       11947       20        -0.0053         4.74        1.895   1.906   quench at I=11941A,
                                                                                                              T=1.9K, ramp rate
                                                                                                              20A/s. Ç

  tqs02a.Quench.070618171826.086   39       11757       20        -0.0057         4.77        1.900   1.901   quench at 11731A,
                                                                                                              T=1.91K, ramp rate
                                                                                                              20A/s, many paramet.
                                                                                                              were tuned for VSDS
                                                                                                              (Conor knows details).

  tqs02a.Quench.070618185329.392   40       11850       20        -0.0059         4.78        1.886   1.887   quench at 11844A,
                                                                                                              T=1.89K, ramp rate
                                                                                                              20A/s.

  tqs02a.Quench.070618204435.298   41       11417       20        -0.0122         5.48        1.866   1.867   quench at 11411A,
                                                                                                              T=1.9K, ramp rate
                                                                                                              20A/s.

  tqs02a.Quench.070619162136.084   42       12391       20        -0.0050         4.84        1.854   1.859   quench at 12383A,
                                                                                                              T=1.86K, ramp rate
                                                                                                              20A/s.

  tqs02a.Quench.070619173320.354   43       12051       20        -0.0053         4.75        1.931   1.932   quench at 12045A,
                                                                                                              T=1.94K, ramp rate
                                                                                                              20A/s.

  tqs02a.Quench.070619185157.071   44       11384       20        -0.0083         4.96        1.911   1.913   quench at 11374A,
                                                                                                              T=1.92K, ramp
                                                                                                              rate=20A/s.

  tqs02a.Quench.070619202645.177   45       11751       20        -0.0070         4.92        1.891   1.891   Quench 45, I = 11741
                                                                                                              A, ramp = 20 A/s, T =
                                                                                                              1.9K, after sawtooth
                                                                                                              0-10.5kA-0 3 times at
                                                                                                              80 A/s

  tqs02a.Quench.070619205921.684   46       11727       20        -0.0063         4.79        2.069   2.068   quench at 11716A,
                                                                                                              T=2.08K, ramp rate
                                                                                                              20A/s.

  tqs02a.Quench.070619212304.332   47       12467       10        -0.0045         4.67        2.173   2.180   quench at 12462.5A,
                                                                                                              T=2.17K, ramp rate
                                                                                                              40A/s (upto 10kA) and
                                                                                                              then 10A/s.

  tqs02a.Quench.070619220625.464   48       11966       20        -0.0069         4.9         2.949   3.077   quench at 11957A,
                                                                                                              T=2.95K, ramp rate
                                                                                                              20A/s.

  tqs02a.Quench.070620081502.510   49       11939       20        -0.0069         4.88        4.440   4.437   Quenching again at
                                                                                                              4.5K. I_q=11932.8A,
                                                                                                              T=4.42K, ramp rate
                                                                                                              20A/s.

  tqs02a.Quench.070620085746.697   50       11941       20        -0.0066         4.77        4.445   4.441   quench at 11935.3A,
                                                                                                              T=4.44K, ramp rate 20
                                                                                                              A/s.

  tqs02a.Quench.070620094054.329   51       11940       20        -0.0069         4.81        4.441   4.437   quench at 11933.8A,
                                                                                                              T=4.44K, ramp rate
                                                                                                              20A/s.

  tqs02a.Quench.070620104514.523   52       11929       20        -0.0073         4.89        4.448   4.444   quench at 11924.5A,
                                                                                                              T=4.44K, ramp rate
                                                                                                              20A/s

  tqs02a.Quench.070620120733.533            1001        20        -0.6323         0.75        4.458   4.458   Manual trip at 1000A
                                                                                                              for Darryl\'s test.

  tqs02a.Quench.070620122618.997   53       11921       20        -0.0067         4.78        4.451   4.452   quench at 11916.7A,
                                                                                                              T=4.45K, ramp rate
                                                                                                              20A/s.

  tqs02a.Quench.070620152411.289            1005        20        0.0021          0.13        4.456   4.453   manual trip at 1000A
                                                                                                              to test noise
                                                                                                              reduction.

  tqs02a.Quench.070620171503.734            11410       20        -0.0024         3.83        4.522   4.536   Trip at 11400A,
                                                                                                              T=4.49K. HFU1 fired at
                                                                                                              400V. HFU2 in
                                                                                                              protection mode.

  tqs02a.Quench.070620182836.832            8006        20        -0.0130         3.48        4.447   4.505   manual trip at 8000A,
                                                                                                              T=4.46K, ramp rate
                                                                                                              20A. HFU1 in test
                                                                                                              mode, HFU2 in protect.
                                                                                                              mode (400V for both).

  tqs02a.Quench.070620190124.970            5007        20        -0.0372         2.32        4.440   4.460   PHeater study, I =
                                                                                                              5000A HFU#1, 400V

  tqs02a.Quench.070620193005.259            3007        20        -0.1187         1.64        4.435   4.448   PHeater study, I =
                                                                                                              3000 A, HFU#1 400V

  tqs02a.Quench.070620200206.825            11414       20        -0.0064         4.38        4.427   4.453   PHeater study, I =
                                                                                                              11400A, HFU#1 300V

  tqs02a.Quench.070621075902.153            8004        20        -0.0171         3.8         4.426   4.427   Heater study: HFU1/2
                                                                                                              capacitor
                                                                                                              voltage=300V. Ramp to
                                                                                                              8000A. HFU1 fired.

  tqs02a.Quench.070621082344.072            5002        20        -0.0441         2.48        4.423   4.418   Heater studies: ramp
                                                                                                              to 5000A. HfU1 fired
                                                                                                              (300V), HFU2 (400V) in
                                                                                                              protection mode.

  tqs02a.Quench.070621084451.523            3004        20        -0.1334         1.77        4.432   4.444   Heater studies: ramp
                                                                                                              to 3000A, HFU1 (300V)
                                                                                                              fired, HFU2 (400V) in
                                                                                                              a protection mode.
                                                                                                              T=4.43K. Ramp rate
                                                                                                              20A/s.

  tqs02a.Quench.070621093553.536            10009       20        -0.0193         5.31        4.416   4.413   Spot heater study:
                                                                                                              trip induced by spot
                                                                                                              heater. HFU1/2 (200V)
                                                                                                              in protection mode,
                                                                                                              all delays 0ms. HFU3 -
                                                                                                              40V.

  tqs02a.Quench.070621100130.437            8008        20        -0.0507         5.98        4.430   4.426   Spot heater study:
                                                                                                              ramp to 8000A (w ramp
                                                                                                              rate 20A/s). HFU1/2
                                                                                                              (200V) in protection
                                                                                                              mode, HFU3 (50V) in
                                                                                                              testing mode. T=4.43K.

  tqs02a.Quench.070621102520.937   54       11930       20        -0.0083         4.87        4.425   4.424   Ramp 68 - quench 54 I
                                                                                                              = 11927 A, 20 A/s, T =
                                                                                                              4.45K
  -------------------------------- -------- ----------- --------- --------------- ----------- ------- ------- ----------------------

**TQS02a Quench History table with first quenching segments**

  -------------------------------- -------- ----------- --------- --------------- ------------ -------------- ------------- ------------- ------------- --------- --------- ------- --------
  **File**                         **\#**   **Current   **dI/dt   **t~quench~**   **QDC**      **1^st^        **t~rise~**   **2^nd^       **t~rise~**   **Mag                       **VSDS
                                            (A)**       (A/s)**                                VTseg**                      VTseg**                     Temp**                      run**

                                                                                                                                                        **Bot**   **Top**           

  tqs02a.Quench.070604130438.013            1002        0         0.0017          WcoilGnd     V1_TrigCvtB1   -0.0003       23A05_23A06   0.0022        4.424               4.421    

  tqs02a.Quench.070604153926.160            1327        50        -0.4000         HcoilHcoil   22A08_22A09    -0.0245       20B05_20B06   -0.0055       4.429               4.427    

  tqs02a.Quench.070604155955.441            1727        20        -0.0027         HcoilHcoil   21A06_21A05    -0.0046       21A08_21A07   -0.0046       4.426               4.422    

  tqs02a.Quench.070604162531.931            5003        20        -0.0238         HcoilHcoil   21B01_21B02    -0.0207       21B03_21B04   -0.0206       4.427               4.425    

  tqs02a.Quench.070605100858.753            1705        20        -0.0218         HcoilHcoil   22B04_22B03    -0.0213       22A02_22A03   -0.0210       4.441               4.442    

  tqs02a.Quench.070605144544.801            8014        20        -0.0434         HcoilHcoil   23A09_23A10    -0.0448       23A07_23A08   -0.0402       4.430               4.426    

  tqs02a.Quench.070605155126.832            8009        20        -0.0357         HcoilHcoil   23A09_23A10    -0.0382       23A07_23A08   -0.0339       4.428               4.432    

  tqs02a.Quench.070605162403.186            8006        20        -0.0365         HcoilHcoil   23A09_23A10    -0.0382       23A07_23A08   -0.0336       4.432               4.433    

  tqs02a.Quench.070605183235.446            5004        20        -0.0325         WcoilGnd     23A05_23A06    -0.0315       HP_HN         -0.0291       4.433               4.430    

  tqs02a.Quench.070605184714.684   1        9906        20        -0.0148         HcoilHcoil   21A08_21A07    -0.0160       21A06_21A05   -0.0139       4.439               4.436   1

  tqs02a.Quench.070606094913.966   2        10326       20        -0.0105         HcoilHcoil   21B05_21B06    -0.0095       21B01_21B02   -0.0091       4.442               4.437   2

  tqs02a.Quench.070606102106.918            1732        20        -0.0192         HcoilHcoil   22B04_22B03    -0.0098       22A02_22A03   -0.0097       4.443               4.441   3

  tqs02a.Quench.070606111444.461   3        11165       20        -0.0106         HcoilHcoil   20B01_20B02    -0.0106       Q24P_Q24N     -0.0106       4.435               4.434   4

  tqs02a.Quench.070606115518.721   4        11441       20        -0.0085         HcoilHcoil   20A10_20A09    -0.0091       20A08_20A07   -0.0077       4.436               4.436   5

  tqs02a.Quench.070606123347.247   5        11578       20        -0.0108         HcoilHcoil   21B03_21B04    -0.0105       21B01_21B02   -0.0098       4.437               4.434   6

  tqs02a.Quench.070606140258.865   6        10634       20        -0.0155         HcoilHcoil   21B03_21B04    -0.0171       21B01_21B02   -0.0132       4.430               4.427    

  tqs02a.Quench.070606144702.183   7        11642       20        -0.0109         HcoilHcoil   22A08_22A09    -0.0119       22A06_22A07   -0.0113       4.437               4.435   8

  tqs02a.Quench.070606152746.043   8        11602       20        -0.0070         HcoilHcoil   20A08_20A07    -0.0081       Q24P_Q24N     -0.0063       4.434               4.435   9

  tqs02a.Quench.070606155359.065   9        11127       20        -0.0120         HcoilHcoil   20A08_20A07    -0.0127       20A10_20A09   -0.0105       4.454               4.454   10

  tqs02a.Quench.070606162133.230   10       11848       20        -0.0073         HcoilHcoil   20A08_20A07    -0.0081       Q24P_Q24N     -0.0053       4.448               4.444   11

  tqs02a.Quench.070606164135.111            1945        20        -0.0122         HcoilHcoil   20A08_20A07    -0.0122       20A10_20A09   -0.0122       4.450               4.448   12

  tqs02a.Quench.070606170223.671   11       11499       20        -0.0115         HcoilHcoil   20A08_20A07    -0.0102       Q24P_Q24N     -0.0071       4.440               4.436   13

  tqs02a.Quench.070606173608.118   12       11706       20        -0.0053         HcoilHcoil   20A08_20A07    -0.0053       20A06_20A05   -0.0048       4.446               4.445    

  tqs02a.Quench.070606180247.881   13       11521       20        -0.0063         HcoilHcoil   20A08_20A07    -0.0077       20A06_20A05   -0.0073       4.452               4.451   15

  tqs02a.Quench.070606183249.640   14       11700       20        -0.0050         HcoilHcoil   20A08_20A07    -0.0052       20A06_20A05   -0.0046       4.453               4.450   16

  tqs02a.Quench.070606190519.154   15       11808       20        -0.0048         HcoilHcoil   20A08_20A07    -0.0048       20A06_20A05   -0.0042       4.454               4.450   17

  tqs02a.Quench.070606193546.194   16       11712       20        -0.0046         HcoilHcoil   20A08_20A07    -0.0050       20A06_20A05   -0.0045       4.457               4.455   18

  tqs02a.Quench.070607085819.744   17       12072       20        -0.0076         HcoilHcoil   21B03_21B04    -0.0073       21B01_21B02   -0.0071       4.467               4.466   19

  tqs02a.Quench.070607093814.124   18       12274       20        -0.0339         HcoilHcoil   20A02_20A01    -0.0309       21A01_22A01   -0.0115       4.452               4.455    

  tqs02a.Quench.070607104128.088   19       11380       20        -0.0098         HcoilHcoil   21B03_21B04    -0.0111       21B01_21B02   -0.0087       4.432               4.433   21

  tqs02a.Quench.070607112015.464   20       11974       20        -0.0109         HcoilHcoil   21B03_21B04    -0.0085       21B01_21B02   -0.0074       4.439               4.434   22

  tqs02a.Quench.070607114524.375   21       12165       20        -0.0050         HcoilHcoil   21B03_21B04    -0.0055       21B01_21B02   -0.0043       4.472               4.465   23

  tqs02a.Quench.070607121514.882   22       12153       20        -0.0052         HcoilHcoil   21B03_21B04    -0.0056       21B01_21B02   -0.0046       4.459               4.457   24

  tqs02a.Quench.070607135538.210   23       12139       20        -0.0055         HcoilHcoil   21B03_21B04    -0.0059       21B01_21B02   -0.0052       4.320               4.383   25

  tqs02a.Quench.070607163339.026   24       12110       20        -0.0046         HcoilHcoil   21B03_21B04    -0.0049       21B01_21B02   -0.0041       4.410               4.410   26

  tqs02a.Quench.070607172917.427   25       12074       20        -0.0050         HcoilHcoil   21B03_21B04    -0.0053       21A01_22A01   -0.0043       4.421               4.421   27

  tqs02a.Quench.070608101421.572   26       12050       5         -0.0055         HcoilHcoil   21B03_21B04    -0.0056       21B01_21B02   -0.0052       4.429               4.427   

  tqs02a.Quench.070608110141.397   27       11964       40        -0.0070         HcoilHcoil   21B03_21B04    -0.0077       21A04_21A03   -0.0069       4.438               4.437   29

  tqs02a.Quench.070608112453.473   28       11717       80        -0.0090         HcoilHcoil   21B03_21B04    -0.0094       21A04_21A03   -0.0080       4.442               4.445   30

  tqs02a.Quench.070608121122.767   29       12011       10        -0.0056         HcoilHcoil   21B03_21B04    -0.0055       21B01_21B02   -0.0045       4.452               4.446   31

  tqs02a.Quench.070608140958.401   30       11407       100       -0.0028         HcoilHcoil   21B01_21B02    -0.0032       23A07_23A08   -0.0032       4.426               4.423   32

  tqs02a.Quench.070609135925.713   31       10217       120       -0.0048         HcoilHcoil   21A01_22A01    -0.0043       23A07_23A08   -0.0034       4.421               4.421   33

  tqs02a.Quench.070609143013.717   32       11844       60        -0.0087         HcoilHcoil   21B03_21B04    -0.0095       21A04_21A03   -0.0084       4.429               4.433    

  tqs02a.Quench.070611162130.884   33       11963       5         -0.0046         HcoilHcoil   21B03_21B04    -0.0049       21B01_21B02   -0.0046       4.410               4.408   35

  tqs02a.Quench.070612140759.260   34       11937       20        -0.0057         HcoilHcoil   21B03_21B04    -0.0064       21B01_21B02   -0.0048       1.853               1.853   36

  tqs02a.Quench.070612152045.937   35       11252       20        -0.0084         HcoilHcoil   21B03_21B04    -0.0092       21B01_21B02   -0.0069       1.881               1.882   37

  tqs02a.Quench.070612172710.819   36       11777       20        -0.0063         HcoilHcoil   21B03_21B04    -0.0073       21B01_21B02   -0.0056       1.815               1.813   38

  tqs02a.Quench.070618140753.334            1516        20        0.0003          WcoilGnd     V1_TrigCvtB1   -0.0003       20A02_20A01   0.0004        1.818               1.819   

  tqs02a.Quench.070618143844.917   37       11446       20        -0.0070         HcoilHcoil   21B03_21B04    -0.0080       21B01_21B02   -0.0053       1.820               1.820   39

  tqs02a.Quench.070618155056.289   38       11947       20        -0.0053         HcoilHcoil   21B03_21B04    -0.0062       21B01_21B02   -0.0043       1.895               1.906   40

  tqs02a.Quench.070618171826.086   39       11757       20        -0.0057         HcoilHcoil   21B03_21B04    -0.0066       21B01_21B02   -0.0045       1.900               1.901   41

  tqs02a.Quench.070618185329.392   40       11850       20        -0.0059         HcoilHcoil   21B03_21B04    -0.0069       21B01_21B02   -0.0049       1.886               1.887   42

  tqs02a.Quench.070618204435.298   41       11417       20        -0.0122         HcoilHcoil   21B03_21B04    -0.0091       21B01_21B02   -0.0077       1.866               1.867   43

  tqs02a.Quench.070619162136.084   42       12391       20        -0.0050         HcoilHcoil   21B03_21B04    -0.0056       21B01_21B02   -0.0046       1.854               1.859   44

  tqs02a.Quench.070619173320.354   43       12051       20        -0.0053         HcoilHcoil   21B03_21B04    -0.0060       21B01_21B02   -0.0043       1.931               1.932   45

  tqs02a.Quench.070619185157.071   44       11384       20        -0.0083         HcoilHcoil   21B03_21B04    -0.0092       21B01_21B02   -0.0066       1.911               1.913   46

  tqs02a.Quench.070619202645.177   45       11751       20        -0.0070         HcoilHcoil   21B03_21B04    -0.0078       21B01_21B02   -0.0056       1.891               1.891   48

  tqs02a.Quench.070619205921.684   46       11727       20        -0.0063         HcoilHcoil   21B03_21B04    -0.0070       21B01_21B02   -0.0055       2.069               2.068   49

  tqs02a.Quench.070619212304.332   47       12467       10        -0.0045         HcoilHcoil   20A08_20A07    -0.0074       20A06_20A05   -0.0073       2.173               2.180   50

  tqs02a.Quench.070619220625.464   48       11966       20        -0.0069         HcoilHcoil   20A08_20A07    -0.0071       20A06_20A05   -0.0066       2.949               3.077   51

  tqs02a.Quench.070620081502.510   49       11939       20        -0.0069         HcoilHcoil   21B03_21B04    -0.0073       21B01_21B02   -0.0066       4.440               4.437   52

  tqs02a.Quench.070620085746.697   50       11941       20        -0.0066         HcoilHcoil   21B03_21B04    -0.0073       21B01_21B02   -0.0056       4.445               4.441   53

  tqs02a.Quench.070620094054.329   51       11940       20        -0.0069         HcoilHcoil   21B03_21B04    -0.0074       21B01_21B02   -0.0056       4.441               4.437   54

  tqs02a.Quench.070620104514.523   52       11929       20        -0.0073         HcoilHcoil   21B03_21B04    -0.0077       21B01_21B02   -0.0074       4.448               4.444   55

  tqs02a.Quench.070620120733.533            1001        20        -0.6323         HcoilHcoil   V1_TrigCvtB1   -0.0034       21A08_21A07   -0.0020       4.458               4.458   56

  tqs02a.Quench.070620122618.997   53       11921       20        -0.0067         HcoilHcoil   21B03_21B04    -0.0073       21B01_21B02   -0.0059       4.451               4.452   57

  tqs02a.Quench.070620152411.289            1005        20        0.0021          WcoilGnd     V1_TrigCvtB1   -0.0003       23A05_23A06   0.0010        4.456               4.453    

  tqs02a.Quench.070620171503.734            11410       20        -0.0024         HcoilHcoil   21A10_21A09    -0.0036       22B02_22B01   -0.0024       4.522               4.536   58

  tqs02a.Quench.070620182836.832            8006        20        -0.0130         HcoilHcoil   21A08_21A07    -0.0112       20A08_20A07   -0.0111       4.447               4.505   59

  tqs02a.Quench.070620190124.970            5007        20        -0.0372         HcoilHcoil   20A06_20A05    -0.0393       23B03_23B02   -0.0385       4.440               4.460   60

  tqs02a.Quench.070620193005.259            3007        20        -0.1187         HcoilHcoil   20A06_20A05    -0.1179       20A08_20A07   -0.1179       4.435               4.448   61

  tqs02a.Quench.070620200206.825            11414       20        -0.0064         HcoilHcoil   20B03_20B04    -0.0031       20B01_20B02   -0.0029       4.427               4.453   62

  tqs02a.Quench.070621075902.153            8004        20        -0.0171         HcoilHcoil   20A06_20A05    -0.0150       20A08_20A07   -0.0150       4.426               4.427   63

  tqs02a.Quench.070621082344.072            5002        20        -0.0441         HcoilHcoil   21A06_21A05    -0.0435       23B03_23B02   -0.0428       4.423               4.418   64

  tqs02a.Quench.070621084451.523            3004        20        -0.1334         HcoilHcoil   22A02_22A03    -0.1260       23B03_23B02   -0.1259       4.432               4.444   65

  tqs02a.Quench.070621093553.536            10009       20        -0.0193         HcoilHcoil   23A09_23A10    -0.0195       23A07_23A08   -0.0169       4.416               4.413   66

  tqs02a.Quench.070621100130.437            8008        20        -0.0507         HcoilHcoil   23A09_23A10    -0.0463       23A07_23A08   -0.0417       4.430               4.426   67

  tqs02a.Quench.070621102520.937   54       11930       20        -0.0083         HcoilHcoil   21B03_21B04    -0.0084       21B01_21B02   -0.0074       4.425               4.424   68
  -------------------------------- -------- ----------- --------- --------------- ------------ -------------- ------------- ------------- ------------- --------- --------- ------- --------

![](media/image3.wmf){width="5.297916666666667in"
height="4.248611111111111in"}

Figure 2.2. Quench history during training at 4.5K, at 1.9K, and during
temperature dependence study. The marker of each quench shows the coil
where it started.

3.  Quenches at temperature between 1.9 and 4.5K

Three quenches (#46 to #48) were performed during magnet warm up from
1.9K to 4.5K. It should be noted that the magnet temperature was not
very uniform when these quenches were performed. Quenches 47 and 48
occurred in coil 20. Ramp 47 started at 40 A/s up to10000 A and
continued up to quench at 10 A/s. The quench current (12467 A) was the
highest ever reached over the whole test.

4.  Ramp Rate Dependence

![](media/image4.wmf){width="6.0in" height="3.8020833333333335in"} Ramp
rate dependence studies at 4.5K were performed on June 8^th^ and 9^th^.
Current ramp rate was varied from 5A/s to 120A/s. Results are shown in
Figure A. Quench current decreases with increasing ramp rate. There were
two ramps done at 5A/s rate, at the beginning and at the end of ramp
rate study. During this study we did not reproduce the highest quench
current (12270A) previously reached with regular ramp rate (20A/s) at
4.5K.

Fig.4.1. Ramp rate dependence of magnet quench current at 4.5K. The
highest quench current previously reached at 4.5K is also shown (square
marker).

5.  Protection Heater studies

Protection heater studies were performed at 4.5K after the magnet
training was completed at 1.9K temperature. In the TQS02a magnet 2 strip
heaters, connected in series, were mounted on the outer layer of each
coil (each heater covered one side of the outer layer). Two Heater
Firing Units (HFU) were configured for 4.8mF capacitance, each connected
to two coil strip heaters in parallel. One HFU was manually fired with
the magnet at a constant current to initiate a quench, while second HFU
was discharged as a protection heater by the system when the quench was
detected. HFUs delay was set to 0ms. HFU1 in a test mode was connected
to the strip heaters on coils 20 and 21. Heater studies were performed
at 300V and 400V HFU capacitor voltages. Protection heater delays are
shown in Figures 5.1 and 5.2. Full markers show the delay to quench
start ( = \|firing time -- quench onset time\|). Open markers show the
delay to quench detection ( = \|firing time\|). The delay to quench
detection depends on the detection threshold (3 V).

![](media/image5.wmf){width="5.833333333333333in"
height="4.135416666666667in"}

Fig.5.1. Protection heater delay at different current and different HFU
capacitor voltage. Full markers show the delay to quench start; open
markers show the delay to quench detection (affected by the high
threshold)

![](media/image6.wmf){width="5.84375in" height="4.145833333333333in"}

Fig.5.2. Detail of previous picture showing delays at high current.

6.  Spot Heater study

Spot heater was mounted on the internal layer of each coil. Initial test
of the Heater Firing Units, when we tried to fire all spot heaters
together with the protection strip heater, and later the spot heater
studies confirmed that spot heater induced quenches were observed only
in two out of four coils: 23 and 21.

Spot heater study was done at 4.5K temperature. HFU1 and HFU2 connected
to the strip heaters were set in a protection mode with 200V capacitor
voltage and 0ms delay. HFU3 was connected to all spot heaters in
parallel. Spot heaters were manually fired at 10000A and 8000A magnet
current (spot heater capacitor voltage was 40V and 50V respectively).
Detection delay time ( = \|quench onset time\|) was measured as 19.6ms
at 10000A and 46.5ms at 8000A. MIITs were 5.3 at 10000A, and 6.0 at
8000A. In both cases first quenching segment was observed in coil 23.

7.  Strain gauge results

Coils 20,21,22,23 were used in TQS02a, having for the first time
Titanium islands instead of Bronze. Similar to previous coils each coil
had 3 strain gauges,: two gauges were attached to the inner layer island
at the magnet center measuring azimuthal and axial strain and a single
axial gauge was placed near the lead end. The gauges where thermally
compensated by gauges mounted on stress-free titanium element. Fully
compensated strain gauges were used on the shell and the axial tie rods.
Measured strain "ε" in two principal directions "z, θ" (and no shear)
were converted into stress "σ" using the relationships below with the
Modulus, and Poisson ratio for titanium (islands) and aluminum (shell):

$\begin{matrix}
\sigma_{\theta} = \frac{E}{(1 - \nu^{2})}(\varepsilon_{\theta} + \text{νε}_{z}) & \sigma_{z} = \frac{E}{(1 - \nu^{2})}(\varepsilon_{z} + \text{νε}_{\theta})
\end{matrix}$.

A comparison of stress in the structure and coils between TQS01,b,c and
TQS02a is shown in the table below.

+------------------+-----------+-----------+-------------+-----------+
| >                | >         | > *       | >           | > *       |
|                  | **TQS01** | *TQS01b** |  **TQS01c** | *TQS02a** |
+------------------+-----------+-----------+-------------+-----------+
| > **Maximum      | > 10602   | > 9932    | > 9570      | > 12269   |
| > current (A)**  | > (4.4K)  | > (4.4K)  | > (4.4K)    | > (4.4K)  |
|                  | >         |           | >           | >         |
|                  | > 11019   |           | >           | > 12463   |
|                  | > (3.2K)  |           | 10521(1.9K) | > (1.9K)  |
|                  |           |           | >           | >         |
|                  |           |           | > 9989      | > 11935   |
|                  |           |           | > (4.4K)    | > (4.4K)  |
+------------------+-----------+-----------+-------------+-----------+
| > **Iss (%)**    | > 87%     | > 82%     | > 80-82%    |           |
|                  | > (4.4K)  | > (4.4K)  | > (4.4K)    |           |
|                  |           |           | >           |           |
|                  |           |           | > 80%       |           |
|                  |           |           | > (1.9K)    |           |
+------------------+-----------+-----------+-------------+-----------+
| > **Shell cold   | > +152    | > +158    | > +142      | > +158    |
| > (MPa) -t**     |           |           |             |           |
+------------------+-----------+-----------+-------------+-----------+
| > **Shell cold   | > +143    | > +140    | > +137      | > +140    |
| > (MPa) -z**     |           |           |             |           |
+------------------+-----------+-----------+-------------+-----------+
| > **Rods cold    | > +113    | > +116    | > +148      | > +118    |
| > (MPa) -z**     |           |           |             |           |
+------------------+-----------+-----------+-------------+-----------+
| > **Island cold  | > -198    | > -202    | > -162      | > -142    |
| > (MPa) -t**     |           |           |             |           |
+------------------+-----------+-----------+-------------+-----------+
| > **Island cold  | > +34     | > +34     | > +39       | > -87     |
| > (MPa) -z**     |           |           |             |           |
+------------------+-----------+-----------+-------------+-----------+

> Many more plot files can be found at:
>
> <http://supercon.lbl.gov/caspi/download/TQS02a/>
>
> The measured strain or stress during the entire test is shown in the
> following figures:
>
> ![](media/image7.jpeg){width="6.0in" height="4.253543307086614in"}
>
> A typical measured stress of coil 21 during cool-down and warm-up is
> shown above.
>
> Coils 20,22, and 23 have shown similar behavior.

![](media/image8.jpeg){width="5.725in" height="4.060416666666667in"}

> ![](media/image9.jpeg){width="5.479861111111111in"
> height="3.8847222222222224in"}
>
> ![](media/image11.jpeg){width="5.629166666666666in"
> height="3.988888888888889in"}
>
> ![](media/image12.jpeg){width="5.854861111111111in" height="4.15in"}

![](media/image13.jpeg){width="5.604861111111111in" height="3.85625in"}

> ![](media/image14.jpeg){width="6.375in" height="4.385416666666667in"}
>
> ![](media/image15.jpeg){width="6.25in" height="4.257638888888889in"}
>
> ![](media/image16.jpeg){width="6.0in" height="4.253543307086614in"}
>
> ![](media/image17.jpeg){width="5.813194444444444in"
> height="4.079166666666667in"}
>
> Axial strain in the island center (see below). The strain in coil 23
> developed an "odd" offset below 10K and its absolute value can not be
> trusted.
>
> ![](media/image19.jpeg){width="5.979861111111111in"
> height="4.113888888888889in"}
>
> Axial strain near the magnet "ends" (above)
>
> ![](media/image20.jpeg){width="5.604861111111111in"
> height="3.972916666666667in"}
>
> ![](media/image21.jpeg){width="5.729861111111111in"
> height="4.061805555555556in"}
>
> ![](media/image22.jpeg){width="5.75in" height="4.075694444444444in"}
>
> ![](media/image23.jpeg){width="5.75in" height="4.075694444444444in"}

.

8.  Quench Antenna Data

> ![](media/image24.wmf){width="6.65in" height="3.716666666666667in"} A
> quench antenna was used during training at 4.5 and 1.9K. The "KEK/HGQ"
> quench antenna consists of three stationary coil segments, each 0.35 m
> long and separated by 0.105 m long couplings. Each coil is made with
> four windings that are sensitive to normal and skew sextupole and
> octupole magnetic flux changes, at a radius of 23 mm. The probe was
> positioned in the bore of the magnet so that the second antenna coil,
> C2, was centered on the magnet coil center. Data analysis showed that
> windings in C2 recorded flux change signals almost for all quenches,
> while C1 windings recorded signals for most quenches at 1.9K. Only few
> signals were recorded in C3. Figure 9.1 shows for every training
> quench the difference between the time of the first signal in the
> quench antenna coils (in all windings of C1, C2 and C3) and the time
> of the quench start according to voltage taps data. This difference is
> within few msec with very few exceptions. Therefore almost all
> training quenches started in the magnet body (mostly close to the lead
> end from quench \# 27). Quench antenna was not installed for the
> quenches 31 and 32 (in preparation to the magnetic measurements).
>
> Figure 9.1 Difference between start of signal in quench antenna coils,
> and in voltage taps during training.

9.  RRR measurement

Estimates of RRR in TQS02a coil segments have been made using data
captured during the final warm up of the magnet. We started warming the
magnet up at about 6:00pm on June 21^st^ reaching 19K temperature at
11:00am on June 22^nd^ and the room temperature (302K) at about 10:00am
on June 29^th^, as shown in Fig.10.1.

Voltages across "fixed" (used for quench protection) and "configurable"
(used for quench onset location) voltage tap segments were monitored by
the Pentek data loggers, while a current of alternating polarity, +/-
10A, was put through the magnet. We used the RRR-configuration of the
amplifier gain for the voltage tap segments (i.e. configuration with
increased gains for the "fixed" and "configurable" voltage tap
segments). Due to underestimated coil resistance in the configuration
file enlarged amplifier gains were set in the RRR-configuration. As a
consequence some of the configurable VT signal voltages reached the 5V
saturation level by noon of June 26 when magnet was at 180K. To keep the
gains unchanged for RRR-measurement we reduced the Kepco trim current
from +/- 10A to +/- 2.5A.

![](media/image25.png){width="6.0in" height="4.239583333333333in"}Data
for all segments are shown in Fig.10.2 and Table 10-I. RRR of inner and
outer coil layers are shown in Fig.10.3.

Fig.10.1: Test stand temperatures during the magnet warm up

![](media/image26.wmf){width="6.0in" height="3.7708333333333335in"}

Fig.10.2: RRR data for different voltage tap segments and coils

![](media/image27.wmf){width="6.0in" height="3.8125in"}

Fig.C: 10.3 of inner and outer coil layers

  ------------ ---------- --------- -------- ---------- --------- -------- --------- --------- -------- --------- ---------- --------
               **Coil               ** **    **Coil     ** **     ** **    **Coil    ** **     ** **    **Coil    ** **       
               20**                          21**                          22**                         23**                 

               R(19K)     R(300K)   RRR      R(19K)     R(300K)   RRR      R(19K)    R(300K)   RRR      R(19K)    R(300K)    RRR

  B12.SnTi                0.387                         0.384                        0.8456                       0.38262    

  B23.Omt      0.413      75.81     183.56   0.423      75.87     179.36   0.34      75.301    221.47   0.335     75.8413    226.39

  B34.OLS      0.0115     2.08      180.87   0.0134     2.089     155.90   0.00925   2.0534    221.99             1.12396    

  B45.ORE      0.002715   0.465     171.27   0.002815   0.4694    166.75   N/A       N/A       N/A                1.01212    

  B56.ORS      0.0109     1.912     175.41   0.0113     1.9217    170.06   0.0093    1.8906    203.29   0.00915   1.92755    210.66

  B6A10.Ramp   0.0157     1.17      74.52    0.0183     1.1494    62.81              0.2009             0.015     1.14665    76.44

  A80.IRS+RE   0.0097     1.703     175.57   0.0098     1.6998    173.45   0.0075    1.6204    216.05   0.0083    1.7011     204.95

  A68.ILS+LE   0.0145     2.453     169.17   0.01475    2.4436    165.67   0.011     2.4013    218.30   0.0115    2.4801     215.66

  A56.T2-5     0.1095     20.122    183.76   0.109      20.086    184.28   0.0884    20.0902   227.26   0.0888    20.0864    226.19

  A45.T6       0.0253     5.246     207.35   0.0287     5.2498    182.92   N/A       N/A       N/A      0.0241    5.40218    224.17

  A34.T7Rs     0.0114     2.121     186.05   0.0114     2.123     186.23             0.1053             N/A       N/A        N/A

  A23.Imt      0.364      68.422    187.97   0.362      68.443    189.07   0.295     68.3712   231.77   0.316     70.331     222.57

  A12.SnTi                0.371                         1.667                        0.3688                       0.036351   
  ------------ ---------- --------- -------- ---------- --------- -------- --------- --------- -------- --------- ---------- --------

Table 10-I: RRR data for all segments

10. Quench origin location

Time-of-flight quench-origins were calculated for several quenches
during the initial training of TQS02, using the following three times:
quench-onset, 1^st^ exit and 2^nd^-exit (when available). The
time-of-flight distance assumed the known V-tap locations and equal
quench-propagation speeds for both quench-fronts. If the time of the
2^nd^ quench-front's exit was not visible (e.g., when the V-tap DAQ was
blinded by the dump-transient voltage) the following quench-speeds were
assumed: 20m/s (inner layer), and 10m/s (outer layer). The following
quench-origins were analyzed: Q1,2,3,4,7,8,10,11,15,17,25, 26,27, as
indicated in the table below, plotted on a Theta/Z-scaled version of the
two pole-turns (Fig. 10.1).

![](media/image28.wmf)

![](media/image29.wmf){width="7.045138888888889in"
height="1.645138888888889in"}

Fig. 10.1: Quench-origin plot for some of TQS02's early training
quenches. Refer to the table to identify the coil. The first three
training quenches originated in the outer layer ends, close to its
transit across the inner pole-island. Middle training quenches occurred
in the inner pole turn straight-sections. 4.5K plateau quenches always
had multiple starts in the outer layer. The first onset occurred near
the middle of the lead-in side (bottom of plot) a second pole-turn onset
originated shortly later just inside the V-tap demarcating the start of
the interlayer "Ramp" segment (top left in plot).

11. Magnetic Measurements

The field quality magnetic measurements were made with the VMTF vertical
drive system and LHC/EMS rotating harmonic coil readout cart. Several
data sets were captured: warm z-scan before cool down, z-scans at 4.5 K
and 1.9K. A full cold measurement program is described below. A 0.1 m
long tangential probe, with 2 dipole, 2 quadrupole and 1 tangential
windings, was utilized. This probe was specially built for these
measurements with a radius of 2.17 cm, optimized to the warm finger ID.
The positive direction of the z-axis for the scans is pointing from the
magnetic center to the lead end, from which the probe was inserted. Each
measurement (e.g., at one z-position) contains data from at least 25
full rotations of the probe, and z-scans steps were equal to the length
of the probe.

The cold magnetic measurement program at 4.5 and 1.9 K is consisted of
the following measurements:

a.  Z-scans at 4.5 K: 6.5, 8.0 and 10.5 kA

b.  Z-scans at 1.9 K: 12.3 Tm/m (LHC injection, estimated to be 0.583
    kA), 100 Tm/m (estimated to be 5.15kA). A measurement at high
    current (\~I~qmax~-- 0.6kA) was not performed at 1.9 K.

c.  Eddy current loops: 20 40 and 80 A/s up to 10 kA with the probe
    positioned in the center of the magnet

d.  Dynamic effects measurement, which included a current accelerator
    profile, similar to the one used in LHC MQXB quads (15 min. duration
    of the injection plateau and the probe positioned in the center of
    the magnet).

All magnetic measurement results are presented at 17 mm reference
radius, the official radius adopted for LHC. A detailed magnetic
measurements summary is posted at the following URL:

HTTP://tdserver1.fnal.gov/velev/magnets/web/magnets/TQS02/TQS02a_mag_meas.html

Table 11.1 summarizes the quadrupole strength (T\*m/m) and transfer
function (TF) versus the excitation current, measured when the probe was
positioned at the center of the magnet body (z=0 m). The 16% degradation
of the TF at high currents is expected due to the iron saturation.

Fig. 11.1 shows the TF versus z coordinate profiles at 0.58, 5.15 and
10.5 kA. The integral magnetic lengths are calculated to be 0.712, 0.723
and 0.735 m at these currents.

  ----------- ---------- ---------- ---------- ---------- ---------- ----------
  Requested   -10        10         583        4000       5155       10000
  Current (A)                                                        

  Measured    -10.81     10.80      583.84     3997.74    5152.42E   9995.80
  Current (A)                                                        

  Field       0.2336     0.2336     12.48      83.92      104.58     184.92
  (T\*m/m)                                                           

  TF (T/kA)   21.71      21.62      21.38      20.99      20.29      18.50
  ----------- ---------- ---------- ---------- ---------- ---------- ----------

Table 11.1 Strength and TF at different currents in the body of the
magnet

![](media/image30.wmf){width="6.551388888888889in"
height="5.147916666666666in"}

Figure 11.1. The magnet TF versus z coordinate at 0.583, 5.15 and 10.0
kA.

Table 11.2 summarizes the harmonics at injection (0.583 kA) and maximum
measured current (10.5 kA), averaged over the magnet (left) and for the
center body position (right). In general, the field harmonics are in the
order of several units. The b~5~ and b~6~ at injection are observed to
be relatively large, \~ 10 units, similar to TQS01c.

Table 11.2. TQS02 body and average harmonics at different currents

  ------------------ ------------- ------------ ------------- -------------
                     Average       Average      Body only     Body only

  Multipole(units)   Injection     10.5 kA      Injection     10.5kA

  b_3                1.71E+00      8.50E-01     1.90E+00      6.16E-01

  b_4                -1.77E-03     4.51E-01     5.14E-02      5.66E-01

  b_5                7.75E+00      -3.69E-01    7.54E+00      -7.40E-01

  b_6                -1.29E+01     1.72E+00     -1.29E+01     1.85E+00

  b_7                -2.88E-03     9.83E-03     1.11E-02      2.37E-02

  b_8                -6.73E-04     -2.15E-02    2.31E-03      -1.92E-02

  b_9                -7.62E-02     2.29E-02     -9.43E-02     1.12E-02

  b_10               1.03E-01      -1.25E-02    1.17E-01      -6.81E-03

  a_3                3.49E-01      2.46E-01     5.37E-01      4.04E-01

  a_4                -2.15E+00     1.13E+00     -1.99E+00     1.44E+00

  a_5                4.40E+00      -2.30E-01    3.94E+00      -7.49E-01

  a_6                4.49E-01      1.07E-01     3.62E-01      9.59E-02

  a_7                -3.79E-02     -2.50E-02    -4.78E-02     -4.20E-02

  a_8                6.43E-03      -1.37E-02    3.12E-02      2.29E-03

  a_9                -3.09E-02     9.25E-03     -4.34E-02     6.34E-04

  a_10               2.55E-03      5.24E-03     2.96E-03      3.56E-03
  ------------------ ------------- ------------ ------------- -------------

Figure 11.2 shows the dodecapole versus time. The current profile used
in this measurement was derived from the profile of production inner
triplet LHC quadrupole (LQXB) measurements. The duration of the
injection porch was set to 15 min at 12.8 T, accordingly to the LHC
specifications. One can observe that *the b6 decay and snapback*, which
are commonly observed in NbTi magnets, *are not present* (see the time
interval from \~700 to \~1600 s).

Current loops at 20, 40 and 80 A/s for TQS02 quadrupole have been
executed. The b~6~ difference between the ramp rate loops is small,
indicating small or negligible eddy current effect on the hysteresis
loop, similar to what was observed in TQS01c measurements. The b~6~
hysteresis loops are shown in Figure 11.3.

![](media/image31.wmf){width="6.451388888888889in"
height="5.669444444444444in"}

Figure 11.2. Dodecapole (b~6,~ in units) versus time (s): current
profile simulates an accelerator operation.

![](media/image32.wmf){width="6.3493055555555555in"
height="4.788194444444445in"}

Figure 11.3. Dodecapole (b~6~) versus excitation current at different
ramp rate 20 (red), 40 (green) and 80 (blue) A/s.

References

1)  1\. C. Donnelly, G. Ambrosio, G. Chlachidze, S. Rahimzadeh-Kalaleh

    *"TQS02a Voltage Spike Analysis",*

    FNAL TD-07-015, LARP note July 2007