KAGRA Logbook

VIS (SRM)

panwei.huang - 15:12 Tuesday 28 August 2018 (5914)

SRM OSEM Calibration

Panwei and Enzo:

We completed the calibration for the 6 OSEMs for SRM.

But one of them shows lower output voltage (12550 cnt which is around 3.9 v) when the OSEM flag is not covering the light from the LED (OSEM No.62).

Please let us know if you think we cannot tolerate this and we will assemble a new one.

Note: In calibration, once we connect the OSEM cable and the flag is not covering the light from LED, we see the OSEM output goes up dramatically to its maximum output, then it drifts down slowly to a smaller steady value. After we move the flag to full range, this effect no longer shows up.

We guess it may come from the impulse of the power supply of the OSEM.

Images attached to this report

Comments to this report:

yoshinori.fujii - 19:36 Tuesday 28 August 2018 (5925)

I think we can contniue to use the OSEM-#62. This looks due to individual differences of LED/PD.. Actually we are using such OSEMs (#52, #58, #36 and so on)
http://klog.icrr.u-tokyo.ac.jp/osl/?r=2359
http://klog.icrr.u-tokyo.ac.jp/osl/?r=3988
http://klog.icrr.u-tokyo.ac.jp/osl/?r=4846

By the way, can you measure the noise levels when the OSEM-flag is fixed at the center of the linear range and at the both edges? Measurement with just one OSEM would be enough for this.

panwei.huang - 10:13 Tuesday 09 October 2018 (6460)

Original data (x/mm , y/counts):

No.59: x=[5, 5.5, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 8, 8.5, 9, 9.5, 10]; y=[46, 69, 226, 349, 522, 818, 1312, 2050, 3114, 4426, 5916, 7255, 8480, 9763, 11114, 12460, 13570, 14313, 15272, 15435, 15456, 15484, 15536]

No.60: x=[5, 5.5, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 8, 8.5, 9, 9.5, 10]; y=[41, 95, 561, 985, 1657, 2664, 3923, 5185, 6391, 7534, 8841, 10056, 11108, 11906, 12423, 12788, 13040, 13213, 13569, 13614, 13621, 13656, 13678]

y=[41, 95, 561, 985, 1657, 2664, 3923, 5185, 6391, 7534, 8841, 10056, 11108, 11906, 12423, 12788, 13040, 13213, 13569, 13614, 13621, 13656, 13678]

No.61: x=[5, 5.5, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 8, 8.5, 9, 9.5, 10]; y=[41, 85, 335, 491, 791, 1329, 2158, 3314, 4789, 6074, 7288, 8449, 9716, 11054, 12046, 12790, 13308, 13608, 14140, 14215, 14218, 14254, 14280]

No.62: x=[5, 5.5, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 8, 8.5, 9, 9.5, 10]; y=[44, 102, 536, 879, 1396, 2192, 3283, 4484, 5595, 6668, 7802, 8952, 9946, 10704, 11265, 11676, 11960, 12152, 12498, 12552, 12561, 12607, 12631]

No.63: x=[5, 5.5, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 8, 8.5, 9, 9.5, 10]; y=[45, 85, 271, 361, 485, 697, 1105, 1799, 2812, 4022, 5291, 6502, 7649, 8966, 10302, 11525, 12502, 13204, 14255, 14357, 14370, 14425, 14451]

No.64: x=[5, 5.5, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 8, 8.5, 9, 9.5, 10]; y=[42, 66, 256, 395, 604, 950, 1547, 2432, 3700, 5178, 6602, 8018, 9418, 10850, 12116, 13246, 14081, 14585, 15279, 15351, 15366, 15404, 15424]

y=[46, 69, 226, 349, 522, 818, 1312, 2050, 3114, 4426, 5916, 7255, 8480, 9763, 11114, 12460, 13570, 14313, 15272, 15435, 15456, 15484, 15536]