Absolute Calibration of a Ppm-Precise HV Divider for the Electron Cooler of the Ion Storage Ring CRYRING@ESR

A novel ppm-precise absolute calibration method for precision high-voltage dividers

“…The main goal was to check the reproducibility and long-term stability of the newly developed absolute calibration method as well as its capability to measure the voltage dependency of scale factors. The measurements were performed with two ppm-precise HV dividers K65 [14] and G35 [15], which were also used as reference mutually to crosscheck the results. In addition we built a HV divider with precision resistors [16] with a scale factor M A ≈ 100 : 1 and a relative uncertainty of in the order of 1 • 10 −5 , which was used as reference unit (see figure 7).…”

“…For the systematic uncertainties we determined the 24 h uncertainties of each DVM with a reference voltage source. In order to derive the real scale factor M B from M B we measured the differential scale factor for different voltages up to 35 kV (see figure 10 and 11) and fitted the data 15 according to equation (10) to obtain the coefficients a, b c and d. We also included the low voltage calibration values measured as described in section 2 (see set-up in figure 2) into the analysis. Since in that measurements the real scale factor is determined, we used a combined fit to describe all data points 16 .…”