FM ILT Results: Mechanisms

1
FM ILT Results Mechanisms

• H. Feuchtgruber, H. Dannerbauer,
• N. Geis, C. Hartinger, U. Klaas,
• P. Royer

2
Overview of Sub-systems

• Grating Launch Lock
• Grating Mechanism
• Chopper
• Filter Wheel SPEC
• Filter Wheel PHOT
• Calibration Sources CS1, CS2
• Heater Blue and Red
• Flasher Blue and Red

3
Test Phases

• Short Functional Tests Warm, LHeI and LHeII
• Mechanism controller parameter optimization
• ILT with blue spectrometer array connected to
  DMC
• ILT with red spectrometer array connected to
  DMC

4
Grating Launch Lock

• Opened during the SFT warm
• on 12-Oct-06
• Closed on 4-Jan-07 (warm)

12-Oct-06
4-Jan-07
5
Grating Mechanism (1)

• Results
• - Control loop parameters have been
• optimized for operation with
• DMC EQM
• - Grating health check successfully
• passed
• - Accessible range measured
• - Variety of scans with different
• step-sizes explored
• - Duration of step transitions and
• stability on position is within spec.
• - We plan to do still better on with
• the FM DMC and improved OBSW
• - Grating speed can be set to
• 4 deg/s as a compromise between
• small step stability vs. grating
• speed for large transitions.

6
Grating Mechanism (2)

• Results
• - Control loop parameters have been
• optimized for operation with
• DMC EQM
• - Grating health check successfully
• passed
• - Accessible range measured
• - Variety of scans, different
• stepsizes and speeds explored
• - Duration of step transitions and
• stability on position is within spec.
• - We plan to do still better on with
• the FM DMC and improved OBSW
• - Grating speed can be set to
• 4 deg/s as a compromise between
• small step stability vs. grating
• speed for large transitions.

7
Grating Mechanism (3)

• Results
• - Control loop parameters have been
• optimized for operation with
• DMC EQM
• - Grating health check successfully
• passed
• - Accessible range measured
• - Variety of scans and different
• stepsizes explored
• - Duration of step transitions and
• stability on position is within spec.
• - We plan to do still better on with
• the FM DMC and improved OBSW
• - Grating speed can be set to
• 4 deg/s as a compromise between
• small step stability vs. grating
• speed for large transitions.

8
Grating Mechanism (4)

• PACS-ME-ECR-009 Expansion of grating angular
  throw
• - CQM 40.6 degrees insufficient accessible
  wavelength range
• - FM accessible range 44.62 degrees
• working range 43.1 degrees (low grating
  output)
• order measured specification
• 45000 1050000
• n3 73.2µm 34.8 µm 72µm - 56µm
• n2 109.8µm 52.2µm 105µm -
  72µm
• n1 219.6µm 104.3µm 210µm - 105µm

9
Grating Mechanism (5)

• Problems
• - Limit switch at positive end is
• broken (NCR-ME-229)
• - Non-optimum software handling of
• grating open loop operation
• (corrected in latest DMC OBSW)
• - Grating position information was lost
• when turning the filter wheel
• (corrected in latest DMC OBSW,
• SPR-0651)

10
Chopper (1)

• Requirements for science operations
• deviations from final position lt 1 duty cycle gt
  80 _at_10Hz
• Requirements for calibration operations
• deviations from final position lt 2 duty cycle gt
  70 _at_10(5)Hz

• Duty cycle of chopper has been within
  specification at sub-
• system level
• Chopper performance is coupled to DMC
  capabilities
• Control loop optimization hasnt been completed
  due to
• NCR-233

11
Chopper (2)
12
Chopper (3)
Science FOV Measured - up 13ms - down
34ms Specification 10ms
Need for asymmetry Parameters in control loop
identified
13
Chopper (4)
Calibration FOV Measured - up
33ms - down 60ms Specification 15(30)ms
14
Chopper (5)

• Non-conformance PACS-ME-NCR-233
• ? Chopper has been de-integrated, further
  investigations
• ongoing, replace by original FM chopper
• DMC OBSW modifications defined

15
Filter Wheels (1)

• Both wheels turned during all
• test phases, at warm and cold
• temperatures without any
• problems.
• Positional reproducibility of FW
• PHOT is within specification, FW
• Spec positional accuracy is not
• yet determined due to bug in
• commanding script (corrected in
• the meantime). However
• there are no indications that it
• may not be in spec.

16
Filter Wheels (2)

• Both wheels turned during all
• test phases, at warm and cold
• temperatures without any
• problems.
• Positional reproducibility of FW
• PHOT is within specification, FW
• Spec positional accuracy is not
• yet determined due to bug in
• commanding script (corrected in
• the meantime). However
• there are no indications that it
• may not be in spec.

17
Calibration Sources (1)

• Time constants
• Homogeneity
• Emissivity

18
Calibration Sources (2)

• Time constants

- Complete tests not carried out. - Heat-up
from off-state to 70.5(CS1)/76.5(CS2) K -
Measurements are done in spectroscopic HK
mode t(70.5K) 2700sec t(76.5K) 3100sec

• Worse than req. (Stable after 30min), but only
  slightly different from CQM

19
Calibration Sources (3)

• Time constants

- Complete tests not carried out. - Heat-up
from off-state to 70.5(CS1)/76.5(CS2) K -
Measurements are done in spectroscopic HK
mode t(70.5K) 2700sec t(76.5K) 3100sec
Stability in spec.

• Worse than req. (Stable after 30min), but only
  slightly different from CQM

20
Calibration Sources (4)

• Time constants

- Complete tests not carried out. - Heat-up
from off-state to 70.5(CS1)/76.5(CS2) K -
Measurements are done in spectroscopic HK
mode t(70.5K) 2700sec t(76.5K) 3100sec
Stability in spec.

• Worse than req. (Stable after 30min), but only
  slightly different from CQM

21
Calibration Sources (4)

• Homogeneity

CS2
CS1
22
Calibration Sources (5)

• Homogeneity FOV OGSE BB1 at 22K
• ? Significantly improved since CQM, however
  there is still some small structure on top

Straylight issues to be investigated still !
CS2 76.5K
CS1 70.5K
23
Calibration Sources (6)

• Emissivity CS2 (76K)
• Measured against
• cryogenic OGSE
• blackbody at 30K
• - Values are within
• specified range,
• however change from
• CQM to FM not effective
• The analysis did not yet
• include straylight effects
• and accurate temperature
• derivation for CS2
• The OGSE BB was not
• measured at consistent
• chopper positions

CQM values for CS2
24
Heater Blue Red

• Both heaters passed the
• functional tests

• 2 different current settings during
• SFT warm

25
Heater Blue (1)
26
Heater Blue (2)
expected optimum
IID-B Spec.
27
Heater Blue (3)

• Detector
• curing test
• Ih10mA

28
Flashers Blue Red (1)
blue
red
blue
red
Emitter
Brass wires
Nylon suspensions
Copper wires
29
Flashers Blue Red (2)
blue
red

• Short functional tests passed

30
Flashers Blue Red (3)
Blue _at_ 0.7mA
Red _at_ 0.4 mA

• Measure a sequence
• of flasher currents to
• check illumination
• pattern (up into
• saturation)

31
Flashers Blue Red (3)
blue
red
41
40
26
24
4
5
23
27
46
26
68
56
15
35
Peak signal
Peak signal
Shadow by walls

• Calculated illumination pattern of the arrays
  (prior to cone)
• Including the detector cones results in
  significantly
• different signal pattern as seen by detector