LCGT LCGT 2011/5/17, 1
TAMA --> CLIO ---> LCGT TAMA 300m基線長 三鷹(NAOJ) CLIO 100m 神岡 低温鏡 2 2011年5月17日火曜日
LCGT (Large-scale Cryogenic Gravitational wave Telescope) Underground in Kamioka, Japan Silent & Stable environment 3km baseline Cryogenic Mirror 20K saffhire substrate Plan 2010 : construction start now! 2014 : first run in normal temperture 2017- : observation with cryogenic mirror <-- partially funded in this year. ( 9.8 billion yen, about 2/3 of whole fund.) 3
LCGT... LCGT 4
TAMA LIGO advanced detector LCGT aligo, avirgo 5
GWIC (Gravitational Wave International Committee) RoadMap https://gwic.ligo.org/ https://gwic.ligo.org/roadmap/roadmap_100814.pdf 6
10-20 LCGT LCGT (varrsed, BWstudy2009) LCGT (varrseb, Bwstudy2009) Strain Equivalent Noise spectrum [1/ Hz] 10-21 10-22 10-23 10-24 advanced Virgo advanced LIGO(ZERO DET, High P) advanced LIGO(NS-NS) Einstein Telescope ET_B ET_C 6 7 8 9 10 2 3 4 5 6 7 8 9 100 2 3 4 5 6 7 8 9 1000 frequency [Hz] 7
8
9
9
9
h(t) h(f) 10
h λ energy detector ( ) voltage [V] digital value # of ticks
x in G x error x H feedback = Hx error x feedback x error = G (x in x feedback ) x error = x feedback = G 1+GH x in GH 1+GH x in 12
x in h G x error x H feedback = Hx error x feedback x error = G (x in x feedback ) x error = x feedback = G 1+GH x in GH 1+GH x in 12
x in h G x error x feedback H (ADC: Analog-to-Digotal Converter) 13
x in h G x error x feedback H ADC + + DAC 14
x in h G x error x feedback H 15
= (t i, N i )
Fundamental Noises in Laser Interferometer Nose Spectral Density [m/ Hz] f -5/2 Seismic f -1/2 Thermal noises --> cryogenic Photon Shot Noise & Radiation Pressure Noise --> high power laser, cavity, massive mirror Seismic Pendulum Thermal --> vibration isolation --> silent site = underground Radiation Press Mirror Thermal Photon Shot Noise Frequency [Hz] 17
TAMA ( )
TAMA DAQ system (2000 ) workstation (HDAQ) VXI workstation (mirror archive) watch hut Interferometer servo etc. workstation (MDAQ) NFS workstation (HDAQ onlin monitor) Remote X11 servers workstation (EPICS) environmental NFS NFS workstation (diagnosis, environmental monitor etc) scp NFS Figure 1: Schematic of DAQ System (with major hosts only) 19
TAMA DAQ system (2000 ) data amount ~1GB/hour 20
LCGT Laser Beam Network Sampling Clock / Time Info. Station DAQ Station Frame Maker Environment ADC Diagnosis ADC Station Station Station Station Light Source Station Main System Station Station Frame Maker Main ADC Pre Analysis Data Distributer Raw Data Archive Diagnosis Server Time Keeper From Another DAQ system 21
22
LCGT 1 raw data ~ 600 TB/ Virgo, LIGO Frame data format 23
chunked data stream! cf chunked!
Frame Data Format frame
raw data ~600 TB/ + ~ 1 PB/ sampling freq. factor x 27
h
ṽ(f) [V/rHz] [/rhz] TAMA [Hz] h(f) [Hz]
optical gain Fundamentals of Interferometric Gravitational Wave Detectors, P.R.Saulson, World Scientific
(GH<<1) (GH>>1)
(625Hz )
ADC ( ) ADC (linear system )
example: h(f) [Hz] [1/ Hz]
s = h + n v(t) v(t) s(t) or ṽ(f) s(f) (...) frame format s(t) or s(f) (h(t) or h(f)) 35