1 KAGRA vibration isolation meeting (12th of September 2012)
   2 
   3 Attendees: Takahashi, Uchiyama, DeSalvo, Majorana, Conte, Yamamoto
   4 
   5 Ryutaro: Yesterday, some people attended the meeting
   6 of the Physical Society of Japan in Kyoto.
   7 Ryutaro and Takanori gave talks about the vibration isolation.
   8 
   9 The Inverted Pendulum (IP) of the pre-isolator is successfully controled
  10 by Takanori.
  11 The diagonalization of the sensors was done. He demonstrated the damping
  12 control
  13 (not inertia damping, but viscous damping) and DC control.
  14 He used only LVDT. The unity gain frequency is 0.5Hz.
  15 The resonant frequency of IP is 0.13 Hz.
  16 Takanori has already put his slides (in Japanese) on JGW doc.
  17 http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=1263
  18 And you can check what he is doing via the blog.
  19 http://gwclio.icrr.u-tokyo.ac.jp/lcgtsubgroup/vibrationisolation/
  20 
  21 Riccadrdo: He dicussed the payload assembly tools in Lucca.
  22 Ryutaro must prepare the order. However, before that,
  23 he should convince the Executive Office that this tool is immediately
  24 necessary.
  25 
  26 Ettore: He is going to IMPEX on the next Tuesday.
  27 So, he can not attend this meeting on the next week.
  28 He will introduce why we need the sapphire fibers and ribbons
  29 and discuss the issues. On the week of 24th of September,
  30 Alessandro and Riccardo will visit IMPEX. We can expect some
  31 progress after Ettore's visit and that they can obtain it.
  32 If you have questions about the fibers and ribbons, let Ettore know.
  33 Kazuhiro will
  34 summarize the questionl list tomorrow or the day after tomorrow.
  35 
  36 Unfortunately, the delivery of the short fibers from IMPEX is delayed.
  37 But we expect that there is not technical problems.
  38 
  39 Since Ettore asked Kazuhiro the progress of the thermal conductivity
  40 measurement of
  41 sapphire fibers, Kazuhiro explained briefly. Uchiba-kun, who is a graduate
  42 student
  43 of Tsubono group, is measuring a straight (withoug nail heads) and
  44 polished fiber.
  45 The measured conductivity is comparable with those of Tomaru.
  46 http://www.sciencedirect.com/science/article/pii/S0375960102009854
  47 But we expected the thermal conductivity is sevaral times larger than
  48 those of Tomaru
  49 because the fiber radius of this experiment is larger.
  50 
  51 Ettore asked the progress of the sapphire bonding experiment. He found the
  52 paper about
  53 the bonding from Perugia and sent it after this meeting
  54 (Classical and Quantum Gravity 27(2010)045010).
  55 
  56 Riccardo presented the talks about the seismic isolation and composite
  57 mirror suspension
  58 in LVC meeting but not so many questions and comments.