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⇤ ← Revision 10 as of 2009-12-05 02:34:00 →
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← Revision 30 as of 2009-12-07 19:09:37 → ⇥
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Editor: KojiArai
Comment:
Deletions are marked like this. Additions are marked like this.
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Whether contamination or not The round trip loss in the 40m cavity is estimated to be around 170ppm. We are going to confirm whether this comes from the hydrocarbon contamination and wiping of the mirror by acetone and isopropyl may result in improvement of the optical loss, or not.
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== Measurements before the vent == In addition we can evaluate the use of those solvents. If we observe the degradation of the loss or the finesse, we will forbid them.

== Measurements before the cleaning ==
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=== - Finesse measurement === Most recent arm visibility measurement has been done on Oct 07, 2009. [http://nodus.ligo.caltech.edu:8080/40m/2070 corresponding elog entry]

{{{
Measured arm reflectivity R_cav:
X arm: 0.875 +/- 0.005
Y arm: 0.869 +/- 0.006
}}}

=== - Cavity pole measurement ===
Most recent arm visibility measurement has been done on Nov 10, 2009. [http://nodus.ligo.caltech.edu:8080/40m/2226 corresponding elog entry]

{{{
Measured arm cavity pole frequency f_pole [Hz]:
X arm: 1720 +/- 70
Y arm: 1650 +/- 70
}}}

=== - Estimated finesse and arm loss ===

== Measurements after the cleaning ==
=== - Visibility measurement ===
=== - Cavity pole measurement ===
=== - Estimated finesse ===
-------
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  * wiping preparation
  * wiping practice
  * aux beam as a reference....align to overlap in vacuum
  * Input PZT (strain gauge) /HV off/OMC PZT HV
    * update snap shots: sus, strain gauges,IOO, OMC....etc (OMC has no strain gauges)
    * recenter: IP-ANG-POS, oplevs..... at full lock
  * test drive crane drives
  * clean clean-tools again
  * keep eyes on particle counter: abort over 10,000
  * cut some viton tips for spare earthquake stop screws
  * look that we have good RGA scan
  		   * Wiping Preparation
  * Vent Preparation
Line 25: Line 41:
  * Vent / Open ETMX if possible
  * Take pictures before touching
  * Record positions of the mirrors (OSEMs/OPLEVs)		   * Pre-vent check 8:00~
  * Vent from 9:30~
  * Stop venting ~14:00
  * Check OSEM/Oplev values
  * Wipe ETMX 14:00~
   * Open ETMX 14:00~15:00
   * Mirror wiping 15:00~16:00
   * Check alignment / Close up 16:00~17:00
Line 30: Line 51:
  * ETMX wipe   * (ETMX wipe)
Line 32: Line 53:
  * ITMY wipe
  * Check of the optics in the chambers (ITMY)
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  * IPANG beam
  * ITMX position (pushing screws)
  * ITMX BB leveling
  * measure the distance of the breadboards
  * check of the optics in the chambers
  * ITMY wipe
Line 41: Line 58:
   * Record ITMX position (pushing screws)
   * ITMX BB leveling
   * measure the distance of the breadboards
  * 40m meeting
  * Check of the optics in the chambers (ITMX/BS)
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 * '''Thursday:''' - Evacuation  * '''Thursday:'''
  * Evacuation
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 * '''Friday:  '''  * '''Friday:'''
  * Reserve
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 * '''Friday, 4 Dec: '''
  * Practice cutting viton, so we can get the correct sizes if we need to replace stops. (Jenne)
  * Recenter all of our pointing PDs (oplevs and IP_POS, IP_ANG).
  * Update snapshots of all MEDM screens that have alignment information.
  * Move extraneous equipment around chamber doors: Make sure we have clear access (esp. seismometers need moving)		  * '''~Friday, 4 Dec: '''
  * Wiping preparation
   * Chemicals:
    * Small bottles (like 250ml) / 3 bottles each (no matter how the size is)
    * '''Acetone''' Spectral Grade, dehydrated (if possible)
    * '''Isopropyl alcohol''' Spectral Grade, dehydrated (if possible)
   * glass sylinges with metal needles, 50ul, at least three sets
   * mirror wiping paper, usual lens paper from Kodak or whatever
   * tools (well cleaned)
   * clamps to mark the position of ITMX: 3pcs
   * halogen light or whatever: light during the work

 * '''Vent Preparation '''

  * Prepare the air cylinders (x6)
  * Clean clean-tools again
  * Alignment
   * Recenter: IPANG/POS, oplevs with the mirrors fully aligned '''[DONE]'''
   * Align the aux beam as a reference '''[DONE]'''
   * Update snapshots of all MEDM screens for OSEMs/OPLEVs/QPDs/PZT&strain gauges '''[DONE]'''
  * Move extraneous equipment around chamber doors: Make sure we have clear access (esp. seismometers need moving) '''[DONE]'''
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  * Before venting, check that all the recentering done on Friday is still good. If not, redo.
  * Vent
  * During vent, practice drag wiping a spare random optic (maybe a 2" CVI optic?) 		  * '''Check before the vent'''
   * Close: PSL shutter and place manual block into main beam path
   * Prepare left handed pressure regulator for instrument grade air,
   * Identify "VACUUM NORMAL" state of valve positions based on the 40M VACUUM SYSTEM STATES and SEQUENCES user manual
    * Note: this operation is FULLY MANUAL and two person required to change condition (one has to be experienced )
    
   * Before venting, check that all the recentering done on Friday is still good. If not, redo. '''[DONE]'''
   * Check: particle count
   * Turn off: all OPLEV damping to all sus '''[DONE]'''
   * Turn off: PZT power to IOO steering and OMC '''[DONE]'''
   * Turn on the shutter for the PSL beam. Put a manual block so that any failure can put the beam into the vacuum system '''[DONE]'''
   * Turn off all HV in vacuum (Input/Output PZT) '''[DONE]'''
   * Check the jam nuts of the bellows on the vacuum system (Two at the vertex, one at the MC tube) '''[DONE]'''

  * '''Vent'''
   * Follow "vacuum normal to chamber open" from manual
    * Isolate the main vacuum manifold '''[DONE]'''
    * Introduce N2 up to 25torr '''[DONE]'''
    * Change the N2 cylinder to the instrument grade air. We need 6 cylinders to fill up the tank.
    * Approximate vent rate 150torr/hour
 
  * During the vent - Door opening preparation
   * Test drive crane drives
   * Move and store abs. length setup to a safe place '''[DONE]'''
   * Practice drag wiping a spare random optic (with an arbitrary 2" CVI optic)
   * Practice cutting viton, so we can get the correct sizes if we need to replace stops. (Jenne)
   * Cut some viton tips for spare earthquake stop screws

  * Environment
   * Keep eyes on particle counter: abort over 10,000
   * Look that we have good RGA scan
Line 59: Line 128:
  * Take photos of ETMX before touching   * Take photos of ETMX before touching

  * '''ETMX wipe'''

Cleaning of the suspended test mass (Dec 2009)

Motivation

The round trip loss in the 40m cavity is estimated to be around 170ppm. We are going to confirm whether this comes from the hydrocarbon contamination and wiping of the mirror by acetone and isopropyl may result in improvement of the optical loss, or not.

In addition we can evaluate the use of those solvents. If we observe the degradation of the loss or the finesse, we will forbid them.

Measurements before the cleaning

- Visibility measurement

Most recent arm visibility measurement has been done on Oct 07, 2009. [http://nodus.ligo.caltech.edu:8080/40m/2070 corresponding elog entry] 

Measured arm reflectivity R_cav:
X arm: 0.875 +/- 0.005
Y arm: 0.869 +/- 0.006

- Cavity pole measurement

Most recent arm visibility measurement has been done on Nov 10, 2009. [http://nodus.ligo.caltech.edu:8080/40m/2226 corresponding elog entry] 

Measured arm cavity pole frequency f_pole [Hz]:
X arm: 1720 +/- 70
Y arm: 1650 +/- 70

- Estimated finesse and arm loss

Measurements after the cleaning

- Visibility measurement

- Cavity pole measurement

- Estimated finesse

Overview of the plan

  • We plan for the vent from 7th Dec to 11th Dec in 2009.

  • Preparation

    • Wiping Preparation
    • Vent Preparation

  • Monday:

    • Pre-vent check 8:00~
    • Vent from 9:30~
    • Stop venting ~14:00
    • Check OSEM/Oplev values
    • Wipe ETMX 14:00~
      • Open ETMX 14:00~15:00
      • Mirror wiping 15:00~16:00
      • Check alignment / Close up 16:00~17:00

  • Tuesday:

    • (ETMX wipe)
    • ETMY wipe
    • ITMY wipe
    • Check of the optics in the chambers (ITMY)

  • ~ Wednessday:

    • ITMX wipe
      • Record ITMX position (pushing screws)
      • ITMX BB leveling
      • measure the distance of the breadboards
    • 40m meeting
    • Check of the optics in the chambers (ITMX/BS)

  • Thursday:

    • Evacuation

  • Friday:

    • Reserve

Detailed plan

  • ~Friday, 4 Dec:

    • Wiping preparation
      • Chemicals:
        • Small bottles (like 250ml) / 3 bottles each (no matter how the size is)

        • Acetone Spectral Grade, dehydrated (if possible)

        • Isopropyl alcohol Spectral Grade, dehydrated (if possible)

      • glass sylinges with metal needles, 50ul, at least three sets
      • mirror wiping paper, usual lens paper from Kodak or whatever
      • tools (well cleaned)
      • clamps to mark the position of ITMX: 3pcs
      • halogen light or whatever: light during the work

  • Vent Preparation

    • Prepare the air cylinders (x6)
    • Clean clean-tools again
    • Alignment

      • Recenter: IPANG/POS, oplevs with the mirrors fully aligned [DONE]

      • Align the aux beam as a reference [DONE]

      • Update snapshots of all MEDM screens for OSEMs/OPLEVs/QPDs/PZT&strain gauges [DONE]

    • Move extraneous equipment around chamber doors: Make sure we have clear access (esp. seismometers need moving) [DONE]

  • Monday:

    • Check before the vent

      • Close: PSL shutter and place manual block into main beam path
      • Prepare left handed pressure regulator for instrument grade air,
      • Identify "VACUUM NORMAL" state of valve positions based on the 40M VACUUM SYSTEM STATES and SEQUENCES user manual
        • Note: this operation is FULLY MANUAL and two person required to change condition (one has to be experienced )

      • Before venting, check that all the recentering done on Friday is still good. If not, redo. [DONE]

      • Check: particle count

      • Turn off: all OPLEV damping to all sus [DONE]

      • Turn off: PZT power to IOO steering and OMC [DONE]

      • Turn on the shutter for the PSL beam. Put a manual block so that any failure can put the beam into the vacuum system [DONE]

      • Turn off all HV in vacuum (Input/Output PZT) [DONE]

      • Check the jam nuts of the bellows on the vacuum system (Two at the vertex, one at the MC tube) [DONE]

    • Vent

      • Follow "vacuum normal to chamber open" from manual

        • Isolate the main vacuum manifold [DONE]

        • Introduce N2 up to 25torr [DONE]

        • Change the N2 cylinder to the instrument grade air. We need 6 cylinders to fill up the tank.
        • Approximate vent rate 150torr/hour
    • During the vent - Door opening preparation
      • Test drive crane drives

      • Move and store abs. length setup to a safe place [DONE]

      • Practice drag wiping a spare random optic (with an arbitrary 2" CVI optic)
      • Practice cutting viton, so we can get the correct sizes if we need to replace stops. (Jenne)
      • Cut some viton tips for spare earthquake stop screws
    • Environment
      • Keep eyes on particle counter: abort over 10,000
      • Look that we have good RGA scan
    • Open ETMX
      • Take photos of ETMX before touching

    • ETMX wipe

    • Close up ETMX with light doors for the night

  • Tuesday:

  • Wednesday:

  • Thursday:

  • Friday:

Optics_Cleaning (last edited 2012-01-03 23:02:40 by localhost)