Conveners
Instrumentation: Instrumentation
- Takayuki Tomaru
We developed a cryogenic displacement sensor for KAGRA cryogenic payloads. The cryogenic payload is the suspension system to cool down a sapphire mirror at 20 K in KAGRA. And, the sapphire mirror is suspended the suspension called Type A suspension which height is about 13.5 meter including the cryogenic payload. The cryogenic payload has four stages called platform and marionette and...
The BS, SR2, SR3 and SRM optics in KAGRA are supported by "Type B" suspensions incorporating an inverted pendulum stage, three stages of geometric anti-spring filters and a payload consisting of the optic and a recoil mass suspended from an intermediate mass and intermediate recoil mass. All four suspensions have now been installed and are in advanced stages of commissioning. We report on...
Measuring the transfer function is a good way to know the feature of the suspension in frequency space. However, when we start the observation, we cannot use the real suspension in KAGRA. So it is significant to build a model in state space. In state space, one can use ABCD matrices which includes the information of suspensions. And from this, one can simulate the transfer function and...
The test masses in KAGRA are suspended by so-called Type-A suspensions. Type-A suspension consists of 9-stage pendulum and the lower 4-stages is to be operated in a cryogenic temperature. In this talk, the status of the installation of the type-A suspensions and an activity with X-arm cavity are going to be reported.
The KAGRA gravitational-wave detector is rapidly being commissioned and integrated towards the joint observation run with LIGO and VIRGO.
The laser-interferometer type of the gravitational-wave detectors are based on very complicated optical systems, with numerous feedback control loops at an extreme high precision. Since the interferometer is so complex, there are many possible states of the...
We will report the progress and future prospect of the KAGRA Physical Environmental Monitors, which is called PEM.
PEM installation is one of the important task to join the O3 observation
because they play a important role of the noise identification/hunting.
Also, because KAGRA is a underground/cryogenic experiment,
the environmental information will be a important information for the...
We are conducting/will conduct the commissioning test of the X-arm cavity, the Y-arm cavity, Dual-Recycled Michelson, and Dual-Recycled Fabry-Perót Michelson toward the O3 observation. As the calibration activities, measuring the IFO response, developing the reconstruction pipeline, and the installing the photon pressure calibrator(pcal) are in progress. The test of the reconstruction...
In this talk, the status of the input optics for the O3 will be reported. The input optics is one of the subsystems in KAGRA, and the objective of the input optics is to provide the stable laser to the main interferometer.
Several in-air and in-vac optics are included in our subsystem. They stabilize the laser frequency and the intensity, reduce the beam jitter, apply the modulation needed for...
