Patrick, Sheila, Jenne, Eric For the first part of the test, we injected our fiducial CBC waveform (same one used in ER7) and tried raising the LIMIT value on the hardware injection block in order to address saturation problems observed in ER7. During ER7, the LIMIT was 200. We raised it to 400. The first injection did not go through: 1124601535 1 1.000000 cbctest_1117582888_ intent bit off, injection canceled Patrick, Sheila, and Jenne tried to turn on the intent bit, but there was some sort of problem, which will be alog'ged separately. As a temporary work-around, we turned off the tinj intent-bit check and injected again: 1124602724 1 1.000000 cbctest_1117582888_ successful Patrick determined that the injection produced a maximum |amplitude| of 15 counts coming out of the injection block, which seemed to indicate that the original LIMIT value of 200 was sufficient. However, an alarm went off to indicate that there was saturation at ETMY. Thus, the saturation problem cannot be solved by tinkering with the INJ block in MEDM. Rather, the problem is occurring downstream on the ETM actuators. We request that Jeff K, Adam M, et al. look into options for avoiding saturation at the ETMs. Next we tried a blind injection using the new blind injection code. The blind injection code does not log injections in EPICS so they are not automatically picked up in the segment database. 1124603111 1 1.000000 cbctest_1117582888_ successful The blind injection was clearly visible. The ETM saturation warning went off again. The injection was logged correctly in the blind injection blindinj_H1.log: current time = 1124603049... Attempting: awgstream H1:CAL-INJ_BLIND_EXC 16384 /ligo/home/eric.thrane/O1/Hardw areInjection/Details/Inspiral/H1/cbctest_1117582888_H1.out 1 1124603111 Injection successful. All of these injections were carried out with scale factor = 1; (that's the 1.000000). The injection file, described in a comment below, is a 1.4 on 1.4 BNS, optimal orientation, at D=45 Mpc. It is the same waveform used in previous ER tests.
There are a couple of things to watch out for when performing CBC hardware injections, based on iLIGO experience:
For the ER7 injection we used an SEOBNRv2 waveform that has a ringdown at the end, hoping that this turn off would not trigger an impulse. However, for BNS masses, the turn off and ringdown is pretty sharp. I've asked Chris check that there are no "whooper" effects with the SEOBNRv2 waveform, but we haven't had chance to do this yet. For a SpinTaylorT4 waveform (the other waveform CBC wants to inject), there will definitely be a step, so this needs to be checked and rolled off carefully.
One other comment on the test: what scaling in awgstream did you use? That waveform looks monstously loud (eyeball SNR > 20). That's much louder than would be useful for a blind injections, but good for helping us find whooper effects.