Mapping of MICE Magnets M.A Leonova MAP spring 2014 1 Mapping MICE - PowerPoint PPT Presentation

Mapping of MICE Magnets M.A Leonova MAP spring 2014 1

Mapping MICE Magnets  SS2 = SSU mapping completed 5 – 20 June 2013  SS1 = SSD mapping completed 6 – 22 March 2014  FC  Last week the mapper was unpacked and installed by CERN group  Mapping to start soon (Next week?) M.A Leonova MAP spring 2014 30 May 2014 2

SSU and SSD Field Measurements  Survey – without the shield plate – with the shield plate  Surveyed of fiducial markers:  done from 4 stations to get the best fit  establish a coordinate system with X axis along the cold mass axis (beam axis) Z axis vertical Y axis completes (x,y,z) right coordinate system origin at the DS end of cold mass for SSU origin st US end of Vacuum Vessel for SSD  Mapping Device measurements:  mapper axis as the disk moved through the magnet  both rails to get disk rotation as it moves through the magnet  Calibration of longitudinal positions vs. encoder of the Mapping Device  50 cm steps  2 cm steps M.A Leonova MAP spring 2014 30 May 2014 3

SSU Survey M.A Leonova MAP spring 2014 30 May 2014 4 All suports are not welded to the magn. Note the clamp being d li i h

SSD Survey M.A Leonova MAP spring 2014 30 May 2014 5

SSU and SSD Survey M.A Leonova MAP spring 2014 30 May 2014 6

Mapping Apparatus The system is characterized by the following uncertainties: • ± 0.5 mm probe radial position; • ± 1 mrad disk rotation angle; • < 0.5 mm longitudinal position; • ± 2 mT magnetic field measurement (in 1 to 4 T region). M.A Leonova MAP spring 2014 30 May 2014 7

SS2 Field Measurements  Mapping Device X axis along the magnet on direction: SSU opposite to beam direction; SSD in direction of the beam Z axis vertical Y axis completes (x,y,z) right coordinate system M.A Leonova MAP spring 2014 30 May 2014 8

SS2 Field Measurements Two main modes of mapping:  “fast” map: 5-cm longitudinal steps 4 disk rotation positions: 0° & 180° and 40° & 220°  “full” map: 2-cm longitudinal steps 20° disk rotation steps M.A Leonova MAP spring 2014 30 May 2014 9

SS Design Vacuum vessel bore is 40cm in diameter. Each solenoid has five superconducting Nb-Ti coils wound on a single aluminum mandrel. M.A Leonova MAP spring 2014 30 May 2014 10

SSU Field Measurements  Overview of Field Measurement Studies No Virostek Plate With Virostek Plate 0 A 50% 80% 100% 30 A 0 A 50% 80% 100% Other M1: 31-32 33-34 35-36 37-38 23-24 25-28 Flip Flip M2: Mode Mode 43-44 39-40 29-30 ECE: 41-42 E1: 51-52 E2: 53-54 95% 0 A 50% 80% 100% 0 A 50% 80% 100% 10 A 49-50 12 1-4 45-46 5 16 13 14 21-22 17 Solenoid Solenoid Mode Mode 55-59 11 6-10 18-19 15 20 M.A Leonova MAP spring 2014 30 May 2014 11

SSD Field Measurements  Overview of Field Measurement Studies Run numbers were re-started No Virostek Plate With Virostek Plate Other 0 A 50% 80% 100% 0 A 50% 80% 100% Other 69-70 19-20 21-22 23-24 25-26 Flip Flip 27-28 Mode Mode 29-34 30 A 0 A 50% 80% 100% 0 A 50% 80% 100% Other E2: 43 42 56-57 58-59 66-67 E1: 45 41 400 38-39 36-37 Solenoid Solenoid M1: Mode Mode 46 60-65 48-49 M2: 50-51 All: 52-53 C: 54-55 M.A Leonova MAP spring 2014 30 May 2014 12

SSU Field Measurements 4 [at r = 0 mm in Tracker Region] Run # 45-46 Measured Magnetic Field (T) 3.5 B (T) = K * I (A) Value Error 3 Run # 5 K 0.014479 3.804e-06  2 0.001653 2.5 Run # 1-4 2 Run # 11 Run # 47-48 1.5 Run # 12 1 Run # 56-57 0.5 0 0 50 100 150 200 250 300 Current in Central Coil (A) Magnetic field linearity study: The currents in the coils were stable to ~0.05A (maximum variance) over ~2.5-hour measurement, reproducible to ~0.03A. M.A Leonova MAP spring 2014 30 May 2014 13

SSU Field Measurements 4 3.2 Magnetic Field (T) 2.4 B r 1.6 B  B z 0.8 B z at r = 0 mm calc. 0 -0.8 0 500 1000 1500 2000 2500 3000 3500 4000 z (mm) Measured field components, and a numerical calculation of the longitudinal field on magnetic axis using “as-built” coil parameters. Measurements for all 3D Hall probes at different radii are plotted (0 mm – 18 mm), thus, the scatter in the points M.A Leonova MAP spring 2014 30 May 2014 14

SSU Field Measurements 4.02 B z magnetic field component in the 0 mm Settings for "Solenoid Mode" 30 mm 4.01 tracker region: measurements for 3D and 240 MeV/c muon beam 60 mm Hall probes at different radii for a 90 mm Measured Magnetic Field (T) 4 120 mm case without shielding plate, 150 mm measurements at 0 mm for a case with 0 mm - with Shield Plate 3.99 0 mm - calculation shielding plate, and a numerical calculation on axis (no shielding 3.98 plate) using “as-built” coil parameters and measured coil currents. 3.97 3.96 3.95 2000 2200 2400 2600 2800 3000 z (mm) 0.8 Vertical Mapper Axis Displacement 0.6 Displacement (mm) Horizontal 0.4 Radius 0.2 0 -0.2 15 -0.4 2000 2200 2400 2600 2800 3000 z (mm)

SSD Field Measurements 4.02 Correcting data for survey, may improve the apparent field uniformity in the Settings for "Solenoid Mode" 4.01 tracker region. and 240 MeV/c muon beam An ~3% discrepancy between 0 mm - SSU Measured Magnetic Field (T) 4 measurements and simulation is likely 0 mm - SSD due: on axis calculation - field calculation was done for warm 3.99 dimensions; - the # of turns in coils E2, C, and E1 3.98 possibly not as specified; - other? 3.97 Thus, the currents in the coils need to be adjusted to achieve the desired field 3.96 configuration and uniformity. The effect of shielding plate on magnetic 3.95 field inside the solenoid indicating that reduction of current in the outer coil 3.94 (E2) is required. 2000 2200 2400 2600 2800 3000 z (mm) M.A Leonova MAP spring 2014 30 May 2014 16

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See Victoria Blackmore’s talk at CM38 on Field Mapping 18