The PRX and SRX data measured in klog:37209 were analyzed. The cavity lengths were determined by fitting the measured resonance frequencies. The differences between the measured and design cavity lengths were 1.25 ± 0.46 cm for PRX and 2.56 ± 0.45 cm for SRX. Since these differences exceed the estimated uncertainties, the actual PRX and SRX cavity lengths may differ from their design values.
 

• The cavity lengths of PRX and SRX were determined using the following data.

  PRX
  Minimum (MHz)    Maximum (MHz)
  188.6412    188.6851
  162.2368    162.3230
  129.2967    129.3204
  -125.3945    -125.3351
  -158.3357    -158.2847
  -186.8535    -186.7711
  SRX
  Minimum (MHz)    Maximum (MHz)
  195.1800    195.3102
  162.2970    162.4341
  127.1905    127.2084
  -125.3685    -125.2040
  -158.2469    -158.1762
  -193.3183    -193.2740
   

• From the measurement results, the midpoint between the minimum and maximum frequencies was calculated for each resonance. These midpoint frequencies were divided by the FSR calculated from the design cavity lengths (68.2563 m for PRX and 68.2562 m for SRX). The resulting values were rounded to the nearest integers, and the measured frequencies were fitted with the linear function AN+B, where A and B are fitting parameters and N is the rounded integer. The fitting results were as follows.

  PRX (Fig. 1)
  A: 2.19568 ± 0.00015 MHz
  B: −0.2170 ± 0.0099 MHz
  SRX (Fig. 2)
  A: 2.19526 ± 0.00014 MHz
  B: −0.1252 ± 0.0092 MHz
   

• Since A corresponds to the FSR, the cavity lengths were calculated from the fitted values of A.

  PRX
  Measured cavity length: 68.2688 ± 0.0046 m
  Design value: 68.2563 m
  Difference (measured − design): 1.25 ± 0.46 cm
  SRX
  Measured cavity length: 68.2818 ± 0.0045 m
  Design value: 68.2562 m
  Difference (measured − design): 2.56 ± 0.45 cm

  Therefore, the differences between the measured and design values for both PRX and SRX exceed the estimated uncertainties, suggesting that the actual cavity lengths may differ from their design values.