HQ02 Magnetic Measurements Prelim. Results Overview 28Jun2013

Summary of Magnetic Measurements Performed on HQ02 A – 200mm and 100mm long PCB probe ( simultaneous acquisition of both circuits ) B – dual 100mm long PCB probe ( simultaneous acquisition of both circuits ) C – 100mm long Tangential probe

Z-scans 1.9K 964A 14605A scans repeat well 8500A 14605A Saturation effect Zscans on upramp and downramp show stable persistent current magnetization vs. z

Changes in b3/a3 vs Z-position are ~5 units in the straight section - indicating some variations in coil geometry b6 change is ~2 units

From standard deviation of harmonics among 4 non-overlap positions in magnet straight section can estimate amplitude of coil block variations from HQ02 cross-section error simulation. 48  m coil position variation is larger than TQ or HQ01 which were closer to ~30  m Calculation of expected harmonics s.d. using random coil displacement RMS = d

Apply same technique among the three assemblies HQ01d, HQ01e, and HQ02 Coil position variation is ~ 62  m TQ series had ensemble variation of ~140  m Courtesy XRW

Accelerator profile reproducibility test Accelt6 has slower current acceleration i.e. 2A/s^2 instead of 6.5A/s^2

Accelerator profile reproducibility test This cycle was preceded by a quench, so harmonics during pre-cycle are different Reproducibility in all harmonics is very good

Accelerator profile injection porch b6 decay and snap-back About 0.5 units b6 change over 20 min. Fast decay when arrive on porch Resuming ramp from porch plotted vs TIME ramp from porch plotted vs CUR Drift during porch is comparable to dynamic component while ramping ‘Snap-back’ is therefore very small

300A min. cur. Start new file at 14kA to keep size manageable 600A 900A

Ramp up from 50A 300A 600A 900A Accelerator Cycle Reset Current Test

HQ01 – b3 HQ02 – b6 HQ02 – b3 HQ01 – b6 Loops at 20, 40A/s ramp rates HQ02 b6 has small ramp rate dependent effects. HQ02 b3 has some effects, but still much smaller than HQ01

Loops at 40A/s ramp rates at 2K and 4K temperatures Temperature effect on harmonics is very small – except for magnitude of ‘flux jump’ events

HQ01e HQ02 Magnitude of flux jump events seems smaller in HQ02 than in HQ01e3 (owing perhaps to more uniform set of coils); but work in progress… b6 Comparison of ‘flux jump’ events between HQ magnets