KAGRA vibration isolation meeting (12th of September 2012)

Attendees: Takahashi, Uchiyama, DeSalvo, Majorana, Conte, Yamamoto

Ryutaro: Yesterday, some people attended the meeting
of the Physical Society of Japan in Kyoto.
Ryutaro and Takanori gave talks about the vibration isolation.

The Inverted Pendulum (IP) of the pre-isolator is successfully controled
by Takanori.
The diagonalization of the sensors was done. He demonstrated the damping
control
(not inertia damping, but viscous damping) and DC control.
He used only LVDT. The unity gain frequency is 0.5Hz.
The resonant frequency of IP is 0.13 Hz.
Takanori has already put his slides (in Japanese) on JGW doc.
http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=1263
And you can check what he is doing via the blog.
http://gwclio.icrr.u-tokyo.ac.jp/lcgtsubgroup/vibrationisolation/

Riccadrdo: He dicussed the payload assembly tools in Lucca.
Ryutaro must prepare the order. However, before that,
he should convince the Executive Office that this tool is immediately
necessary.

Ettore: He is going to IMPEX on the next Tuesday.
So, he can not attend this meeting on the next week.
He will introduce why we need the sapphire fibers and ribbons
and discuss the issues. On the week of 24th of September,
Alessandro and Riccardo will visit IMPEX. We can expect some
progress after Ettore's visit and that they can obtain it.
If you have questions about the fibers and ribbons, let Ettore know.
Kazuhiro will
summarize the questionl list tomorrow or the day after tomorrow.

Unfortunately, the delivery of the short fibers from IMPEX is delayed.
But we expect that there is not technical problems.

Since Ettore asked Kazuhiro the progress of the thermal conductivity
measurement of
sapphire fibers, Kazuhiro explained briefly. Uchiba-kun, who is a graduate
student
of Tsubono group, is measuring a straight (withoug nail heads) and
polished fiber.
The measured conductivity is comparable with those of Tomaru.
http://www.sciencedirect.com/science/article/pii/S0375960102009854
But we expected the thermal conductivity is sevaral times larger than
those of Tomaru
because the fiber radius of this experiment is larger.

Ettore asked the progress of the sapphire bonding experiment. He found the
paper about
the bonding from Perugia and sent it after this meeting
(Classical and Quantum Gravity 27(2010)045010).

Riccardo presented the talks about the seismic isolation and composite
mirror suspension
in LVC meeting but not so many questions and comments.