SLAC Magnetic Measurements Date: 03-09-1995 Time: 10:25:42 Magnet Name: 2Q10-05 Project: PEP II Injection Line Test Stand: Rotating Coil Stand 2 Measurement Coil: DC100 Operator: STEVEN GARCIA Run Number: 3 Comment: POWER SUPPLY PROBLEM Standardization Currents (A): 160.0 2.0 160.0 2.0 160.0 2.0 Test Currents (A): 10.0 30.0 45.0 60.0 75.0 90.0 100.0 110.0 125.0 140.0 160.0 130.0 100.0 60.0 HARMONICS MEASUREMENTS Date: 03-09-1995 Time: 10:52:32 Magnet Name: 2Q10-05 Project: PEP II Injection Line Run Number: 3 FIELD HARMONICS Magnet Current, Imag = 60.01194 +- 7.362464E-05 A Coil Radius, Rcoil = .0189973 m Coil # Turns, Nturns = 30 Average, # Rotations/Measurement = 8 , # Measurements = 4 N BLn sigBLn THspole sigTH BLn/BL2 sBLn/BL2 (Gm) (Gm) (deg) (deg) (%) (%) --- -------+------- -------+------- -------+------- 1 4.075 0.002 116.33 0.20 1.127 0.001 2 361.644 0.128 -46.50 0.01 100.000 0.000 3 1.025 0.027 -4.86 0.46 0.283 0.007 4 0.128 0.040 -37.88 4.41 0.035 0.011 5 0.353 0.006 -3.02 1.72 0.098 0.002 6 0.827 0.039 -13.08 0.92 0.229 0.011 7 0.273 0.044 18.75 0.99 0.076 0.012 8 0.661 0.089 17.96 0.87 0.183 0.025 9 0.208 0.015 -2.28 0.54 0.057 0.004 10 0.868 0.013 7.13 0.04 0.240 0.004 11 0.018 0.007 2.51 2.31 0.005 0.002 12 0.025 0.006 13.76 0.62 0.007 0.002 13 0.048 0.004 -8.52 0.62 0.013 0.001 14 0.178 0.005 5.24 0.05 0.049 0.001 15 0.013 0.004 -2.97 1.35 0.004 0.001 16 0.011 0.002 1.86 1.19 0.003 0.001 The magnetic center is at X = 191.9 +- 0.4 microns Y = -95.0 +- 0.7 microns The magnetic center is measured relative to the coil axis effectively at the longitudinal center of the magnet. Pitch and yaw are not seen by the coil. View from the non-lead end of the magnet: y ^ | S N --> x N S Date: 03-09-1995 Time: 11:08:37 Magnet Name: 2Q10-05 Project: PEP II Injection Line Run Number: 3 FIELD HARMONICS Magnet Current, Imag = 99.99613 +- 4.539009E-04 A Coil Radius, Rcoil = .0189973 m Coil # Turns, Nturns = 30 Average, # Rotations/Measurement = 8 , # Measurements = 4 N BLn sigBLn THspole sigTH BLn/BL2 sBLn/BL2 (Gm) (Gm) (deg) (deg) (%) (%) --- -------+------- -------+------- -------+------- 1 6.997 0.010 116.88 0.08 1.162 0.002 2 602.200 0.119 -46.67 0.01 100.000 0.000 3 1.619 0.033 -4.06 0.85 0.269 0.005 4 0.177 0.057 -42.87 2.84 0.029 0.009 5 0.594 0.050 -2.13 0.70 0.099 0.008 6 1.183 0.049 -12.74 0.72 0.196 0.008 7 0.406 0.013 19.00 1.16 0.067 0.002 8 0.954 0.073 18.89 0.62 0.158 0.012 9 0.343 0.012 -2.28 0.32 0.057 0.002 10 1.447 0.015 6.96 0.02 0.240 0.002 11 0.032 0.008 1.24 2.24 0.005 0.001 12 0.040 0.004 7.07 12.34 0.007 0.001 13 0.082 0.008 -9.00 0.54 0.014 0.001 14 0.313 0.004 4.95 0.08 0.052 0.001 15 0.028 0.009 -3.88 0.88 0.005 0.001 16 0.021 0.003 1.12 0.95 0.003 0.000 The magnetic center is at X = 196.9 +- 0.3 microns Y = -99.8 +- 0.3 microns The magnetic center is measured relative to the coil axis effectively at the longitudinal center of the magnet. Pitch and yaw are not seen by the coil. View from the non-lead end of the magnet: y ^ | S N --> x N S Date: 03-09-1995 Time: 11:24:53 Magnet Name: 2Q10-05 Project: PEP II Injection Line Run Number: 3 FIELD HARMONICS Magnet Current, Imag = 139.9936 +- 4.11846E-04 A Coil Radius, Rcoil = .0189973 m Coil # Turns, Nturns = 30 Average, # Rotations/Measurement = 8 , # Measurements = 4 N BLn sigBLn THspole sigTH BLn/BL2 sBLn/BL2 (Gm) (Gm) (deg) (deg) (%) (%) --- -------+------- -------+------- -------+------- 1 9.882 0.017 117.79 0.19 1.175 0.002 2 841.134 0.208 -46.67 0.01 100.000 0.000 3 2.247 0.058 -4.23 0.77 0.267 0.007 4 0.353 0.079 35.66 2.62 0.042 0.009 5 0.691 0.065 -3.66 1.86 0.082 0.008 6 1.758 0.061 -11.83 0.27 0.209 0.007 7 0.636 0.054 20.47 1.18 0.076 0.006 8 1.303 0.105 19.38 0.75 0.155 0.013 9 0.486 0.024 -3.11 0.36 0.058 0.003 10 2.047 0.016 6.93 0.07 0.243 0.002 11 0.044 0.007 0.51 1.23 0.005 0.001 12 0.053 0.005 13.75 0.55 0.006 0.001 13 0.128 0.008 -8.78 0.39 0.015 0.001 14 0.424 0.004 5.05 0.04 0.050 0.000 15 0.039 0.005 -2.89 0.80 0.005 0.001 16 0.036 0.003 1.46 0.35 0.004 0.000 The magnetic center is at X = 197.4 +- 0.5 microns Y = -104.1 +- 0.7 microns The magnetic center is measured relative to the coil axis effectively at the longitudinal center of the magnet. Pitch and yaw are not seen by the coil. View from the non-lead end of the magnet: y ^ | S N --> x N S SUMMARY OF THE CALCULATIONS AND CONVENTIONS USED Calculation of GL using a double coil (assumed flat): V2 = (Nturns * velocity * B2 * L)_1 + (Nturns * velocity * B2 * L)_2 = (Nturns1 * Rcoil1 * ang_freq * GL * Rcoil1) + (Nturns2 * Rcoil2 * ang_freq * GL * Rcoil2) = (Nturns1 * Rcoil1^2 + Nturns2 * Rcoil2^2) * ang_freq * GL If Nturns1 = Nturns2 == Nturns12, then V2 = Nturns12 * (Rcoil1^2 + Rcoil2^2) * ang_freq * GL Let Reff^2 = Rcoil1^2 + Rcoil2^2, then V2 = Nturns12 * Reff^2 * ang_freq * GL Or, GL = V2 / (Nturns12 * Reff^2 * ang_freq) Calculation of the harmonics: The integrated radial field for the n'th harmonic at the coil radius is given by BLn(th) = BLn * cos(n*(th - THspole)) The coil voltage is V = Nturns * v_theta * B_r * L Vn(th) = Nturns * velocity * BLn(th) = Nturns * Rcoil * ang_freq * BLn * cos(n*(th - THspole)) The FFT gives Vn and PhiVn in the formula Vn(i) = Vn * cos(n*2pi*i/N + PhiVn) Then, Vn = Nturns * Rcoil * ang_freq * BLn PhiVn = - n * THspole Or, BLn = Vn / (Nturns * Rcoil * ang_freq) THspole = - PhiVn / n Calculation of the magnetic center: Xcenter = - (1/GL) * BL1 * sin(THspole1) Ycenter = - (1/GL) * BL1 * cos(THspole1)