TAMA300 Recombine2 Information

Since 1999/7/11, Updated 2000/9/27

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>> What's new <<

The TAMA project, the Japanese effort for detecting gravitational waves
using the 300m laser interferometer, successfully took 160 hours of data
between August 21, 2000 and September 4, 2000. The best sensitivity of the
detector was about 5x10-21 Hz-1/2 around 1kHz in terms of strain, which
gives a signal-to-noise ratio of 20 to 30 for gravitational waves emitted
from a binary neutron star coalescence in the center of our galaxy. The
interferometer was operated remarkably stably; the longest continuous
locking time was more than 12 hours, and on one day it was locked for more
than 23 hours out of 24 hours. The quality of the data was also drastically
improved compared with our previous runs. First the non-stationary noise
which appeared very often in the previous data runs was significantly
reduced. Secondly approximately 100 signals including feedback and error
signals of various control loops and environmental signals such as ground
motion were also recorded so that any spurious signals in the interferometer
output can be vetoed by correlating them with other channels. The obtained
data are now being analyzed for gravitational wave detection as well as for
diagnosis purposes of the interferometer. We will further improve the
sensitivity and stability of the detector from now until in January 2001 we
plan to hold a two-month data run.
The "Data treatment guideline of TAMA" can be found at the following web site.

>> Work logs <<

Document Library
2000/7 [Japanese] 2000/8 [Japanese]
2000/4 [Japanese] 2000/5 [Japanese] 2000/6[Japanese]
2000/1 [Japanese] 2000/2 [Japanese] 2000/3 [Japanese]

1999/10 [Japanese/English] 1999/11 [Japanese]1999/12 [Japanese]
1999/7 [Japanese] 1999/8 [Japanese/English] 1999/9 [Japanese/English]

>> Current status <<

Optical configuration: Fabry-Perot-Michelson Interferometer with baseline length of 300m

Light source: Injection-locked 10-W Nd:Yag Laser

Mode cleaner: Triangular ring cavity with 10-m length

Control scheme: Common-differential-separated feedback control with frontal modulation

Simplified interferometer diagram (99/10/27 updated)
(Click for the larger GIF image) [EPS File] [CNV File]

>> Latest Sensitivity of TAMA300 <<

Best sensitivity: 1.5 x 10-18 m/sqrt(Hz) (00/8/14)

Displacement sensitivity spectrum and identified noise sources[PDF File] [EPS File]

Strain Sensitivity [PDF File] [EPS File] [MATLAB Program]

History of improvement of the sensitivity [PDF File] [EPS File]

>> Report of Data Taking 2 <<[here]
>> Report of Data Taking 1 <<[here]

Maintained by K. Arai