Cold test of SIS-300 dipole model Sergey Kozub Institute for High Energy Physics (IHEP), Protvino, Moscow region, Russia

Main parameters of dipole model Central field, T6 Ramp rate, T/s1 Operating current, kA6.72 Coil aperture, mm100 Coil length, m1.0 Number of coil layer2 Number of strands in cable36 Collar thickness, mm30 Iron yoke thickness, mm140 Skin thickness, mm10 Stored energy, kJ260 Inductance, mH11.7

SIS300 dipole model

Cold test features Cold test was performed December 2008 Dipole was tested into liquid helium bath at 4.3 K Test program: -- RRR measurement -- Training of magnet -- Ramp rate dependence measurement -- AC losses measurement -- Magnet transfer function measurement RRR of dipole is 187

Training of the SIS-300 dipole model Training curve Dipole reached 6T in third quench, 6.8 T in 18th quench. Current margin of the dipole is 7738/6720 = 1.15 Ramp rate dependence Quench current of the dipole did not decrease up to 1300 A/s (1.15T/s)

Load line of the SIS-300 dipole model Dependences of magnetic field in coil on operating current and critical current of sum of 36 wires on magnetic field. I c/ I 36 = 0.93

Transfer function The transfer function of dipole

Calculated and measured losses of dipole The ramp rate dependence of AC losses in cycles 0 – I max Hysteresis part of AC lossesEddy current part of AC losses (1 T/s)

Magnet GSI 001 Loss (BNL) Hysteresis part (including iron contribution) Eddy current part

Conclusion Magnet reached 6 T after third quench. Maximum magnetic field of 6.8 T was achieved after eighteen quenches. Quench current of the dipole did not decrease up to 1300 A/s (1.15 T/s). AC losses exceed the expected value at amplitude higher than 3 kA. The reason is under study.