"Report to the SSC"

Report to the SSC

Sept 10, 2001

Recent Progress

DEIMOS on tracks and moved onto kinematics mounts

All stages under keyword control including grating transport

Gratings clamp up at all positions

Optical alignment done

FC spots on both FC detectors for stages for all stages

X and Y FC stages characterized

Recent Progress

TV mounted, image motion 3 arc sec (pk-pk), rotation small

LN2 can complete and in testing

Readiness Review held on Aug 21-23

Tractor testing to start this week

Pre Ship Review planned Sept 24-25

Key Dates

Sept 24-25 Preship Review

Oct 8 Start disassembly

Nov 2 Ship mainframe via sea

Nov 8 Mainframe arrives on big island

Nov 15 Hoist MF into K2 dome

Nov 26-30^th Test tractor and kinematics on K2

Dec 6-10^th Install slitmask system

Key Dates

Dec 10-17th Install grating system

Dec 18-10th Install TV system

Dec 22-Jan 5th Home for Christmas

Jan 8-10th Test nose area systems

Jan 11th Install camera

Jan 17th Install dewar

Jan 24-30th Alignment

Jan 31-Feb 14th Testing

Feb 28^th First Light

Effect of PI’s Accident

What Sandy can do now: 10 hours/day

Sit in recliner chair

Get around house slowly with walker

Talk on phone/conference calls

Send/receive faxes

Write longhand

Read/think

2. Added activities this next week:

Computer and e-mail

Effect of PI’s Accident

Ways in which Sandy will be able to help more:

Talking to key people more frequently

Merging information

Minute-to-minute planning with Dave and other unit leaders

Effect of PI’s Accident

Ways in which Sandy will be able to help less:

Reduced oversight and motivating role in Instrument Shop

Reduced insight into test results

No image analysis

Less Zemax modeling, including loss of room-temperature Zemax model for current optical performance (had been promised at PSR)

Net result:

Better high-level functioning

Reduced low-level functioning

Flexure

Slider 2 (mirror, direct imaging)

X=9 px pk-pk, y=14 px pk-pk

Rotation: 0.5 px pk-pk center to edge

Slider 3 (grating)

X=20 px pk-pk, y=13 px pk-pk

Rotation: 1.3 px pk-pk center to edge

Slider 4 (grating)

X=16 px pk-pk, y=9 px pk-pk

Rotation: 0.7 px pk-pk center to edge

Flexure

Slider 3 was predicted by FEA to be the worst case

Marked hysteresis is present depending on PA rotation direction; working FC system is needed

Grating transport system increases flexure when grating inserted at PA angle 0 degrees on sliders 3 &4 (we are working on this)

Capture range of FC system (from actual tests)

X=26 px pk-pk, y=21 px pk-pk

Flexure - Sources

Collimator 4 4

Detector 4 4

Camera* 13 13

Grating box 5 5

Grating sliders 6 6

*Also affect image quality: variable comatic tails

Camera Flexure

Curing flexure in camera is expected to reduce the observed x flexure greatly but increase y flexure a small amount

DEIMOS Camera
The Problem

We believe that it is either cell 4, which has three degrees of adjustment designed into it, or element 3, which is coupled to its cell with shims. All other elements are cemented into place with the exception of element 5, which is held in place by elements 4 and 6.

DEIMOS Camera

Motion in camera confirmed by two independent methods

Double-pass test using a point source at the focal plane, a mirror at the front of the camera, and the Cohu detector, does not need spectrograph or science detector

Analysis by of ghost images taken with the 900 line grating; separately measured detector motion must be subtracted off

Two test agree well

DEIMOS Camera

Original tests in the optics lab did not look for image motion. We tested for image quality using a microscope and the Cohu detector on and off axis. The off axis tests were done at 4 different position angles of the camera by rotating the camera

DEIMOS Camera
Planned Tests before Removal from Instrument

Mahr gage tests directly measuring the motion of cell 4 using pre-existing holes in the camera body.

Pinhole test which will look at the shadows of 2 rings on the back face of element 8 in cell 4. From the magnitude of the motion, we should be able to determine where the moving element in the camera is.

DEIMOS Camera
Planned tests before removal from Instrument

Repeat the double-pass test with the Cohu detector and fiber once dewar is removed from DEIMOS; this will be the key diagnostic test used in the optical lab during the repair process. Measures both the image motion and image quality.

DEIMOS Camera
Repair Plan

Remove the camera from DEIMOS and mount it in a horizontal rotator in the Optics lab, and repeat the double-pass test using the Cohu camera. The camera was in this rotator for the initial optical tests following assembly

DEIMOS Camera
Repair Plan

Remove camera from rotator and disassemble cell 4 from camera.

Test cell 4 for flexure using Mahr gauges

Note this cell has both radial and axial flexures

If translation is caused by radial flexures, remove and replace springs

If translation is caused by axial flexure, re-make flexures

DEIMOS Camera
Repair Plan

If flexure not found in Cell 4, further disassemble camera to Cell 2 which holds element 3 of the camera

Problem may be with shims between element and cell. They may be too small or have fallen out. If so, they will be fixed.

Reassemble camera and test in rotator using the double-pass test and the Cohu detector

Camera Repair Schedule

Oct 8^th Double-pass test with Cohu detector following removal of dewar

Oct 9^th Removal of camera from DEIMOS

Oct 10-16^th Camera tests in Optics Lab

Oct 17-Nov 5^thDisassemble, test and repair

Camera Repair Schedule

Nov 5-9^th Assemble camera

Nov 12-16^th Test camera on test stand

Nov 18-20^th Disassemble and pack camera

Nov 26^th Ship to Hawaii

Nov 27-Dec 3^rdAssemble camera in HI

Jan 11^th Install camera in DEIMOS

Camera Risks and Fallbacks

Testing camera outside DEIMOS in optical lab is not deemed a major risk; Cohu test is good

Risk 1: task is straightforward but takes longer than planned; Vernon Wallace needed to repair camera (ends Nov 26) and to install slitmask system (Dec 3)

Mitigation- Jeff Lewis is experienced with installing slitmask system

Camera Risks and Fallbacks

Risk 2: Solution requires major rebuild of Body 4 axial flexure

Mitigation: We have thought of a better way to fabricate these flexures

Conclude: Less risk to overall schedule by shipping DEIMOS while repairing camera here

DEIMOS Concerns

Larger image motion when slides clamped at PA 0; need to fix this

Finish trolley and test

Adequate test time for all stages; time to analyze and digest test data

DS 9

Observers GUI

Camera flexure (after PSR)

Commission Slider 5 (after PSR)

Red Science array (after PSR)


	DEIMOS on tracks and moved onto kinematics mounts
	All stages under keyword control including grating transport
	Gratings clamp up at all positions
	Optical alignment done
	FC spots on both FC detectors for stages for all stages
	X and Y FC stages characterized


	TV mounted, image motion 3 arc sec (pk-pk), rotation small
	LN2 can complete and in testing
	Readiness Review held on Aug 21-23

	Tractor testing to start this week
	Pre Ship Review planned Sept 24-25


	Sept 24-25 Preship Review
	Oct 8 Start disassembly
	Nov 2 Ship mainframe via sea
	Nov 8 Mainframe arrives on big island
	Nov 15 Hoist MF into K2 dome
	Nov 26-30^th Test tractor and kinematics on K2
	Dec 6-10^th Install slitmask system


	Dec 10-17th Install grating system
	Dec 18-10th Install TV system
	Dec 22-Jan 5th Home for Christmas
	Jan 8-10th Test nose area systems
	Jan 11th Install camera
	Jan 17th Install dewar
	Jan 24-30th Alignment
	Jan 31-Feb 14th Testing
	Feb 28^th First Light


	What Sandy can do now: 10 hours/day
		Sit in recliner chair
		Get around house slowly with walker
		Talk on phone/conference calls
		Send/receive faxes
		Write longhand
		Read/think
	2. Added activities this next week:
		Computer and e-mail


	Ways in which Sandy will be able to help more:
		Talking to key people more frequently
		Merging information
		Minute-to-minute planning with Dave and other unit leaders


	Ways in which Sandy will be able to help less:
		Reduced oversight and motivating role in Instrument Shop
		Reduced insight into test results
		No image analysis
		Less Zemax modeling, including loss of room-temperature Zemax model for current optical performance (had been promised at PSR)
	Net result:
		Better high-level functioning
		Reduced low-level functioning


	Slider 2 (mirror, direct imaging)
		X=9 px pk-pk, y=14 px pk-pk
		Rotation: 0.5 px pk-pk center to edge
	Slider 3 (grating)
		X=20 px pk-pk, y=13 px pk-pk
		Rotation: 1.3 px pk-pk center to edge
	Slider 4 (grating)
		X=16 px pk-pk, y=9 px pk-pk
		Rotation: 0.7 px pk-pk center to edge


	Slider 3 was predicted by FEA to be the worst case
	Marked hysteresis is present depending on PA rotation direction; working FC system is needed
	Grating transport system increases flexure when grating inserted at PA angle 0 degrees on sliders 3 &4 (we are working on this)
	Capture range of FC system (from actual tests)
		X=26 px pk-pk, y=21 px pk-pk


	Collimator 4 4
	Detector 4 4
	Camera* 13 13
	Grating box 5 5
	Grating sliders 6 6
	*Also affect image quality: variable comatic tails


	Curing flexure in camera is expected to reduce the observed x flexure greatly but increase y flexure a small amount



	We believe that it is either cell 4, which has three degrees of adjustment designed into it, or element 3, which is coupled to its cell with shims. All other elements are cemented into place with the exception of element 5, which is held in place by elements 4 and 6.


	Motion in camera confirmed by two independent methods
		Double-pass test using a point source at the focal plane, a mirror at the front of the camera, and the Cohu detector, does not need spectrograph or science detector
		Analysis by of ghost images taken with the 900 line grating; separately measured detector motion must be subtracted off
		Two test agree well


	Original tests in the optics lab did not look for image motion. We tested for image quality using a microscope and the Cohu detector on and off axis. The off axis tests were done at 4 different position angles of the camera by rotating the camera


	Mahr gage tests directly measuring the motion of cell 4 using pre-existing holes in the camera body.
	Pinhole test which will look at the shadows of 2 rings on the back face of element 8 in cell 4. From the magnitude of the motion, we should be able to determine where the moving element in the camera is.


	Repeat the double-pass test with the Cohu detector and fiber once dewar is removed from DEIMOS; this will be the key diagnostic test used in the optical lab during the repair process. Measures both the image motion and image quality.


	Remove the camera from DEIMOS and mount it in a horizontal rotator in the Optics lab, and repeat the double-pass test using the Cohu camera. The camera was in this rotator for the initial optical tests following assembly


	Remove camera from rotator and disassemble cell 4 from camera.
	Test cell 4 for flexure using Mahr gauges
		Note this cell has both radial and axial flexures
		If translation is caused by radial flexures, remove and replace springs
		If translation is caused by axial flexure, re-make flexures


	If flexure not found in Cell 4, further disassemble camera to Cell 2 which holds element 3 of the camera
		Problem may be with shims between element and cell. They may be too small or have fallen out. If so, they will be fixed.
	Reassemble camera and test in rotator using the double-pass test and the Cohu detector


	Oct 8^th Double-pass test with Cohu detector following removal of dewar
	Oct 9^th Removal of camera from DEIMOS
	Oct 10-16^th Camera tests in Optics Lab
	Oct 17-Nov 5^thDisassemble, test and repair


	Nov 5-9^th Assemble camera
	Nov 12-16^th Test camera on test stand
	Nov 18-20^th Disassemble and pack camera
	Nov 26^th Ship to Hawaii
	Nov 27-Dec 3^rdAssemble camera in HI
	Jan 11^th Install camera in DEIMOS


Testing camera outside DEIMOS in optical lab is not deemed a major risk; Cohu test is good
	Risk 1: task is straightforward but takes longer than planned; Vernon Wallace needed to repair camera (ends Nov 26) and to install slitmask system (Dec 3)
		Mitigation- Jeff Lewis is experienced with installing slitmask system


	Risk 2: Solution requires major rebuild of Body 4 axial flexure
		Mitigation: We have thought of a better way to fabricate these flexures
Conclude: Less risk to overall schedule by shipping DEIMOS while repairing camera here


	Larger image motion when slides clamped at PA 0; need to fix this
	Finish trolley and test
	Adequate test time for all stages; time to analyze and digest test data
	DS 9
	Observers GUI
	Camera flexure (after PSR)
	Commission Slider 5 (after PSR)
	Red Science array (after PSR)