Differences between revisions 13 and 29 (spanning 16 versions)

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~
  - check: particle count,jam nuts
  - close: PSL shutter and place manual block into main beam path
  - turn off: PZT power to IOO steering and OMC
  - turn off: oplev damping to all sus
  - 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 )

Vent from 9:30~
- follow "vacuum normal to chamber" open from manual
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
  - Before venting, check that all the recentering done on Friday is still good. If not, redo. [DONE]
  - Turn off all OPLEV damping [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
  - Operate the valves according to the operation 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.
- 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:

-  ⇤ ← Revision 13 as of 2009-12-07 02:45:19 → 
  Size: 4540
  Editor: KojiArai
  Comment:
+   ← Revision 29 as of 2009-12-07 18:47:12 → ⇥
  Size: 5219
  Editor: SteveVass
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 3:
-The round trip loss in the 40m cavity is estimated to be around 160ppm. We are going to confirm wether this comes from the hydrocarbon contamination and wiping of the mirror by acetone and isopropy may result in improvement of the optical loss, 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.
 Line 5:
-In addition we cna evaluate the use of those solvents. If we observe the degradation of the loss or the finesse, we will forbid them.
+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.
 Line 7:
-== Measurements before the vent ==
+== Measurements before the cleaning ==
 Line 26:
+=== - Estimated finesse and arm loss ===

== Measurements after the cleaning ==
=== - Visibility measurement ===
=== - Cavity pole measurement ===
=== - Estimated finesse ===
-------
-Line 30:
+Line 37:
-  * 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 43:
+Line 41:
-  * Vent / Open ETMX if possible
  * Take pictures before touching
  * Record positions of the mirrors (OSEMs/OPLEVs)
+  * Pre-vent check 8:00~
   * check: particle count,jam nuts
   * close: PSL shutter and place manual block into main beam path
   * turn off: PZT power to IOO steering and OMC
   * turn off: oplev damping to all sus
   * 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 )
    
  * Vent from 9:30~
    follow "vacuum normal to chamber" open from manual
  * 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 48:
+Line 61:
-  * ETMX wipe
+  * (ETMX wipe)
-Line 50:
+Line 63:
+  * ITMY wipe
  * Check of the optics in the chambers (ITMY)
-Line 52:
+Line 67:
-  * 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 59:
+Line 68:
+   * 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)
-Line 60:
+Line 74:
- * '''Thursday:''' - Evacuation
+ * '''Thursday:'''
  * Evacuation
-Line 62:
+Line 77:
- * '''Friday:  '''
+ * '''Friday:'''
  * Reserve
-Line 65:
+Line 81:
-Line 67:
+Line 84:
-   * 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)
+   * 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)
-Line 74:
+Line 94:
- * '''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).  (DONE 10pm Friday)
  * Update snapshots of all MEDM screens that have alignment information.  (DONE 10pm Friday)
  * Move extraneous equipment around chamber doors: Make sure we have clear access (esp. seismometers need moving)  (DONE 5pm Friday)
  *   '''o Go to only ITMX mode:''' 
 Save the alignment of the mirrors. Activate X-arm mode. Misalign ITMY and ETMX.
  '''o Inject the aux beam:''' 
 Open the shutter of the aux NPRO. Turn the injection flipper on.
  '''o Look at the faraday output:''' 
 There are several spots but only one was the right one. Confirm the alignment to the thorlabs PD. Connect the oscilloscope to the PD out with a 50Ohm termination.
 Thanks to the Alberto's adjustment, the beat was already there at around 10MHz. After the PD adjustment, the DC was about 600mV, the beat amplitude was about 50mVpp.
  '''o Adjust the aux beam alignment: '''
 Adjust the alignment of the aux beam by '''the steering mirrors before the farady isolator.''' These only change the alignment of the aux beam independently from the IFO beam. 
 After the alignment, the beat amplitude of 100mVpp was obtained.
 
 '''o Closing
 '''Close the shutter of the NPRO. Turn off the flipper mirror. Restore the full alignment of the IFO.
+ * '''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]'''
-Line 94:
+Line 105:
-  * 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'''
   * Before venting, check that all the recentering done on Friday is still good.  If not, redo. '''[DONE]'''
   * Turn off all OPLEV damping '''[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'''
   * Operate the valves according to the operation 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.
 
  * 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 98:
+Line 130:
-  * Take photos of ETMX before touching
+   * Take photos of ETMX before touching

  * '''ETMX wipe'''