Status of the LHO PSLs

LIGO-G010310-00-W

Status of the LHO PSLs

Rick SavageLIGO Hanford Observatory

LIGO Scientific Collaboration MeetingAugust 13-16, 2001

LSC Meeting - August 2001 2LIGO-G010310-00-W

(Selected) PSL issues

Improved optics layout

Optical table support legs

NPRO frequency glitches

Reference cavity tidal correction servo

Intensity stabilization

LSC Meeting - August 2001 3LIGO-G010310-00-W

Revised PSL/IOO optics layout

LSC Meeting - August 2001 4LIGO-G010310-00-W

Improved frequency noise

Number of optical components reduced

Path lengths shortened

Reference cavity orientation changed

LSC Meeting - August 2001 5LIGO-G010310-00-W

Frequency noise – table leg resonances

Bolts tightBolts loose

Stacis system did not work-electronics noise

We will try PEPS systemASAP

LSC Meeting - August 2001 6LIGO-G010310-00-W

2 sec.

5 MHz

NPRO frequency glitches

Approximately one per day

Alternates between step up and step down

T. Kane attributes to mode instability in pump laser diode

LSC Meeting - August 2001 7LIGO-G010310-00-W

Tidal corection servo

Reduce susceptibility to room temperature fluctuations

1 mK >> mcommon mode arm length

LSC Meeting - August 2001 8LIGO-G010310-00-W

Tidal servo (cont.)

LSC Meeting - August 2001 9LIGO-G010310-00-W

Tidal servo sensor noise

25 mK

LSC Meeting - August 2001 10LIGO-G010310-00-W

Intensity stabilization servo

First loop of prototype system operational on2-km interferometer.(R. Karwoski, P. Russell, D. Ottaway)

Inside the loopafter PMC

Outside the loopafter MC

LSC Meeting - August 2001 11LIGO-G010310-00-W

RIN after modecleaner

P/P ~6.8e-8/rtHz

Detector noise floor(laser light blocked)

Light on PD = 0.5 mW >> 4.6e-8/rtHz shot noise limit

Only “inside” loopactive