result of the larger inductance of the choke. The inductance is about twice that of the Booster gradient magnet. The choke measurements predict that the losses will increase ~55.5 watts @ 15 Hz ~70.2 watts @ 20 Hz. from to Figure 4 The end result is Figure 5, SPICE given in for a model of the choke. This 15 Hz, 20 Hz model will be used in simulations at “Girder” 25 Hz. and 26.1 mohms. The DC resistance of the choke is Again, this 10 mohms is about less than the best fit for the model series resistance. As with the gradient magnet model, the choke model requires a bit more series losses and a smaller parallel loss to 15 Hz, 20 Hz 25 Hz match and loss measurements. Simulation: “Girder” SPICE Model Figure 6. The is given below in This “Girder” C_Resonant model was driven with the Booster current. was 15, 20 25 Hz varied such that the resonant frequency was and in the simulation. Table 1 on the next page has various parameters listed. In 15 Hz 20 Hz going from operation to operation the model predicts an increase in power dissipation for the “Girder” 3.9%. of The drive voltage has increased by about “Girder” 9.2 Volts_pk-pk. 50.2 Volts_pk-pk 59.4 (from to 32% +1135/-1096 Capacitor voltage has increased by about to volts. RMS magnets, choke capacitors current in the and is unchanged.
result of the larger inductance of the choke. The inductance is about twice that of the Booster gradient magnet. The choke measurements predict that the losses will increase from ~55.5 watts @ 15 Hz to ~70.2 watts @ 20 Hz. Figure 4 The end result is given in Figure 5, for a SPICE model of the choke. This model will be used in “Girder” simulations at 15 Hz, 20 Hz and 25 Hz. The DC resistance of the choke is 26.1 mohms. Again, this is about 10 mohms less than the best fit for the model series resistance. As with the gradient magnet model, the choke model requires a bit more series losses and a smaller parallel loss to match 15 Hz, 20 Hz and 25 Hz loss measurements. “Girder” Simulation: The “Girder” SPICE Model is given below in Figure 6. This model was driven with the Booster current. C_Resonant was varied such that the resonant frequency was 15, 20 and 25 Hz in the simulation. Table 1 on the next page has various parameters listed. In going from 15 Hz operation to 20 Hz operation the model predicts an increase in power dissipation for the “Girder” of 3.9%. The “Girder” drive voltage has increased by about 9.2 Volts_pk-pk. (from 50.2 Volts_pk-pk to 59.4 Capacitor voltage has increased by about 32% to +1135/-1096 volts. RMS current in the magnets, choke and capacitors is unchanged.