around
1 kHz remained the same as before.
During the observation period, the interferometer was remarkably
stable: it held lock continuously for more than 20 hours several
times, and the overall duty cycle was 86%. The observational
functions of the detector had been drastically improved for this
data run: a newly-developed automatic re-locking system of the
whole interferometer worked reliably, a newly-established quick
look system helped us to find any unusual behavior of the
interferometer as well as the data taking system, and a
newly-implemented medium-speed data acquisition system (64
channels) supplemented the existing high-speed and low-speed data
acquisition system (100 channels) for recording important
detector information. As for the sensitivity of the detector, it
had been improved around 100 Hz by a factor of 10 compared with
the sensitivity obtained in the summer of 2000, resulting in a
significant improvement of the sensitivity to chirps from
heavier-mass binary coalescence. The best strain sensitivity of
around
1 kHz remained the same as before.
During the above-mentioned data run, the interferometer was operated without the power recycling system. Since then we have begun implementing recycling in TAMA300. Around the end of 2001 the recycled interferometer was finally locked for a few seconds for the first time in the history of TAMA300! The lock has been made more and more robust by re-activating the alignment control system for the test masses and by adjusting all the servo systems carefully. As of Jan. 23, 2002, TAMA300 with recycling can hold lock for up to 46 minutes continuously. We will continue to stabilize the lock of the interferometer as well as to improve the sensitivity of the detector.
Please have a look at our home page for more details,
http://tamago.mtk.nao.ac.jp