NSRRC Activity Report 2022

096 NSRRC ACTIVITY REPORT 2022 ................... (3) ................... (4) in which λ U is the period of the undulator and L is the length of the undulator. For the first integral measurement, we used a short current pulse width of 10 μs. The total length of the CuZr wire was 4.4 m; the resistance was 30 Ω. The in-house power supply provides 50 V through the wire and generates a current of 1.66 A. The wire tension, as calculated from the formula, was 6 N, and the wave velocity was 304 m/s. The pulsed wire measurement data were inserted into Eq. (1) to obtain the first integral field, which was compared with the Hall probe measurement, as shown in Fig. 5(a) . The Hall probe system has been used to measure the magnetic field of in-vacuum undulators in other research. 4 The first integral field measurement using the Hall probe system was obtained through numerical integration of the result of the magnetic field measurement. A comparison of the results reveals that the first integral field measurements obtained through the two methods were similar ( Fig. 5(b) ). At the center of the undulator, the difference between the two measurements Fig. 6 : Pulsed wire and Hall probe magnetic field measurements: (a) whole magnetic field, (b) pole lengths. Fig. 4 : Measurement using wire-displacement detection system. PSR = × 100% P Energy saving o P Energy saving o – P x U 1 st (t) = ∫ 0 C t B y ( z ) dz IC δt 2T U 2 nd (t) = ∫ 0 C t ∫ 0 C t’ B y ( z ) dzdz’ I 2T << λ U C 0 > L C 0 ∆ t1st ∆ t2nd PSR = × 100% P Energy saving o P Energy saving o – P x U 1 st (t) = ∫ 0 C t B y ( z ) dz IC δt 2T U 2 nd (t) = ∫ 0 C t ∫ 0 C t’ B y ( z ) dzdz’ I 2T << λ U C 0 > L C 0 ∆ t1st ∆ t2nd Fig. 5 : Pulsed wire and Hall probe first integral field measurements: (a) whole magnetic field, (b) difference in first integral field.