1. MBHSP02 test STATUS and first results
Guram Chlachidze for the 11T Test Group
March 5, 2013
FERMILAB

2. Introduction
MBHSP02 is a 1 m long prototype of the 11 T dipole magnet with
coils #5 and #7
0.7 mm diameter Nb3Sn strand of RRP 150/169 sub-element design
40 strand Rutherford cable with a 11 mm wide and 25 µm thick stainless steel core
Round strand parameters provided by OST
E. Barzi, D.Turrioni, FERMILAB-TM-2552-TD, 2013

3. MBHSP02 instrumentation
10 voltage taps on the inner layer (IL) and 9 voltage taps on the outer layer (OL)
One voltage tap (VT) was missing before cool-down (05B5) and one VT (07A4)
became floating after the ramp # 9

4. MBHSP02 instrumentation (cont’d)
Each coil is equipped with 2 protection heaters
Heaters are composed of 2100 mm long, mm thick and 21.5 mm wide (in mid-plane) or 26 mm wide (in pole area) stainless steel strips used
One layer of Kapton (114 µm) insulation was placed between the heaters and coil

5. MBHSP02 instrumentation (cont’d)
PCB based Quench Antenna (QA) with 3 segments installed on the inner surface of each coil
Lead end QA is located at ~ 2 cm from the VTA6 and return end QA is located ~ 2 cm before VTA8 MD LE RE

6. MBHSP02 instrumentation (cont’d)
61 strain gauges (SG) were installed on shell, coils and bullets for monitoring mechanical strain and coil stresses during the magnet construction and testing
2 resistive temperature sensors (RTD) were mounted at top, middle and bottom of the magnet outer skin

7. Short sample limit (SSL) estimation
Extracted witness samples used for the SSL estimation
Load lines were provided by CERN
Different parameterization of the critical current density used to compare results
E. Barzi, D.Turrioni, FERMILAB-TM-2552-TD, 2013

8. Test status Warm magnetic measurements Feb 18 Cool-down Feb.19-20
Magnetic measurements at 4.5 K Feb. 22
Quench training at 4.5 K Feb. 23, 25-26
Ramp rate Study Feb. 26
Holding quenches at 4.5 K Feb. 28
Quench training at 1.9 K March 1, 4
Quench training and ramp rate study March 5-7
Holding quenches at 1.9 K March 8
Magnetic measurements at 1.9 K March 11-14
Quench protection study, Energy loss measurements, etc

9. MBHSP02 Quench Performance

10. Ramp rate dependence at 4.5 K
Quench at 10 A/s developed in b2_b3, all other quenches in a4_a5 segment of coil #7

11. Splice resistance measurements
B1_B2 resistance measured in coil #7 only
No indication of problem (0.10 ± 0.16) nΩ
More measurements will be done
later, including b1_b3 segment in
coil #7

12. Holding quenches at 4.5 K
Holding magnet at a pre-set current until spontaneous quench happens
Magnet still unstable at 9500 A

13. Holding quenches at 4.5 K (cont’d)
No spikes found before the quench
Ramp #30, quench at A
Ramp #31, quench at 9500 A

14. Voltage Spikes at 4.5 K Voltage spike threshold of 40 mV applied
Noise pick up from power supply

15. Quench locations

16. Quench locations (cont’d)
Most quenches initiated at ends

17. Quench locations at 4.5 K

18. Quench locations at 1.9 K

19. MBHSP02 vs. MBHSP01

20. Guram Chlachidze, CERN-Fermilab internal review
Backup Slides

21. Quenches in mid-plane block
Ramp #28 at 10 A/s