Rotating Coil System Requirements and Specs J Di

Rotating Coil System Requirements and Specs. J. Di. Marco 08 Jun 2018 mag. Meas. Sys. Review_RCreq_jdm_08 Jun 2018 1

As stated in US-Hi. Lumi-doc-818 Rotating Coil Measurements for MQXF are required to measure the following : 1. 2. 3. 4. Integrated quadrupole field with accuracy better than 0. 1% and resolution better than 0. 01% Integral harmonics End field harmonics determined with z increments < 0. 25 m axially Harmonic coefficients accuracy of 5 ppm (10 ppm) of main field in the body region for orders 3 to 10 (11 to 14) at the reference radius of 50 mm. 5. Local twist variation of the quadrupole roll angle as a function of axial position at the 0. 5 mrad level 6. Local magnetic axis (‘waviness’) with respect to external fiducials at the 0. 2 mm level With the present magnetic measurement system at VMTF, a short probe is scanned with accurate Zincrements along the magnet axis. This provides both local and integral data (via summation). Results comparable to Requirements 1 -4 are routinely achieved during these measurements. Ø With a comparable z-positioning accuracy and comparable probe system, Req. 1 -4 should be straightforward to achieve for the full-length Q 1/Q 3 cryo-assembly Ø Req. 5 -6 will depend on determining 3 -D probe location in magnet during changes in Z position mag. Meas. Sys. Review_RCreq_jdm_08 Jun 2018 2