MIF Meeting 2013/2/26
Aso, Yamamoto, Somiya, Nakano, Takahashi, Akutsu, Shibata
Fast beam shutter
- The first prototype was made at Somiya Lab. by Ueda-kun and Tobias. The initial test yielded less than 1msec shut down time. (The shutter was 1mm away from the center of the beam)
- Larger separation from the beam center is necessary to avoid scattering by the shutter blade (roughly 1cm). Bigger capacitor is necessary.
- The prototype system exploded and currently it is not usable.
- Cost to make one is less than 10000JPY.
- We need to estimate the maximum amount of power falling onto the PDs.
- Is it possible to just shutting down the beam at the output of the laser.
- Cosmotec is expensive
- Contact the company making the aLIGO's PD enclosures
- Checked the validity of the methodology by constructing a double pendulum model and comparing it with the hand solved analitic formula. They agreed well.
- Needs better filters to realize true damping.
- Construct a rigid body double-pendulum model next.
- Then construct a Type-B payload only model.
KAGRA de-scoping related
- Length requirement is OK for PRC
- ASC requirement has to be checked
No Green Lock
- Digital Interferometry (Nikhef)
- Noise calculation with RF
- Not an option. Needs more discussion
- How to extract the transmission beam if there is no iKAGRA ETM chamber.
- Ask Nishida-san to work on the estimation of the maximum power falling on the PDs using e2e (Somiya)
- Construct rigid body models of suspensions (Nakano)
- Contact the company making the aLIGO's PD enclosures (Akutsu)
- Alignment noise requirement for PRC/SRC mirrors
- RF DARM noise (Aso)
- Further discussion of BRT (Akutsu)