FM ILT reference numbers

Ge:Ga detector settings

• Blue

  • par	value	comment
    Bias d	198 mV	Bias / heater loop test shows that 168 is slightly better, but 198 used throughout ILT
    Bias r	10 mV	Component level value - to be verified on CRE checkout test
    Heater	1.5 mA	Result from bias / heater loop test is 2.49 K

• Red

  • par	value	comment
    Bias d	69 mV	From bias / heater loop test
    Bias r	10 mV	Component level value - to be verified on CRE checkout test

• Capacitance

  • Decimal	bits	Capacitance (fF)	Ratio
    0	00	140	1
    8	10	240	1.71
    4	01	450	3.21
    12	11	1150	8.21

Grating

• Configuration table: CONFGrat. Column : FMILTFast / FMILT_R_Fast for redundant
• Allowed working range :
  • 32K - 1064K (nominal)
  • 50K - 1082K (redundant)
• Conversion wavelength - grating position (based on ILT-1) :

  • Band	Order	Filter	wavelength	Grating position
    R1	1	n/a	210um	96K
    			100um	991K
    B2B	2	B	100um	301K
    			70um	812K
    B2A	2	A	70um	812K
    			53um	1040K
    B3A	3	A	70um	183K
    			50um	740K

• Key wavelength positions

  • Grating position	Wave Red	Wave Blue Fil A n=3	Wave Blue Fil A n=2	Wave Blue Fil B n=2
    794000	142.43			71.22
    535000	175.63	58.55		87.82
    461000	183.96	61.32		91.99

• Other wavelengths in the PCSS:

  • from spec import *
    
    print wave2GratPos(105., "B2", 8, calVersion="FM_1_0")
    print gratPos2Wave(1000000, "B2", 8, calversion="FM_1_0")

Chopper

• !!! Do NOT use the chopper in redundant mode !!!
• Configuration table CONFChopper / column : CSLopt3-600
• Accessible range : -23500 to +23000
  • At +/- 25000 a field plate limit disables the controller
• Conversion chopper position - angle on the sky - FPU angle relevant for Photometer

  • FPU Angle	Sky Angle	Chopper pos	Comment
    -7.57 deg	-5.79 arcmin	-21350	center CS1 (determined from PHOTO FoV map)
    -2.14 deg	-105 arcsec	-6578	Photometer chop A
    -0.37 deg	-26 arcsec	-1131	Photometer chop field A (point source photometry)
    0.22 deg	0 arcsec	664	Optical zero - value from Zeiss measurements
    0.80 deg	26 arcsec	2450	Photometer chop field B (point source photometry)
    2.57 deg	105 arcsec	7756	Photometer chop B
    7.94 deg	5.74 arcmin	21200	center CS2 (determined from PHOTO FoV map)

• Conversion chopper position - angle on the sky - FPU angle relevant for Spectrometer

  • FPU Angle	Sky Angle	Chopper pos	Comment
    -7.57 deg	-5.79 arcmin	-21350	center CS1 (determined from PHOTO FoV map)
    	-3 arcmin	-11580	large chopper throw A
    	-1.5 arcmin	-5552	medium chopper throw A
    	-0.5 arcmin	-1408	small chopper throw A
    0.22 deg	0 arcmin	664	Optical zero - value from Zeiss measurements
    	0.5 arcmin	2724	small chopper throw B
    	1.5 arcmin	6769	medium chopper throw B
    	3 arcmin	12444	large chopper throw B
    7.94 deg	5.74 arcmin	21200	center CS2 (determined from PHOTO FoV map)

  • Other angles - in the PCSS (release >20070303A) :

    • from all import *
      
      chopPositions = Double1d([-21350.,-6700., 664., 8000., +21200.]) # CS1, PhotLeft, Center, PhotRight, CS2
      
      # Chopper positions to FPU angles (deg)
      print chopPos2FpuAnglePol(chopPositions)
      
      # Chopper positions to Sky angles (arcmin)
      print chopPos2SkyAngle(chopPositions)
      
      
      # FPU angles (deg) to Chopper positions
      fpuAngles = Double1d([-4, 4])
      print fpuAngle2ChopPosPol(fpuAngles)
      
      # Sky angles (arcmin) to Chopper positions
      skyAngles = Double1d([-3, 3])
      print skyAngle2ChopPos(skyAngles)

  • Chopper step to move over one pixel - depends on chopper position

    • Chop pos	Blue phot (3.2")	Red phot (6.4")	Spectro (9.4")
      -21350 (CS1)	164	328	481
      -6700	218	437	641
      664	221	441	648
      8000	209	417	613
      21200 (CS2)	150	300	441

  • At other positions - in the PCSS (release >20070303A):

    •        bluePhotSky = 3.2 # Blue photometer pixel on the sky (arcsec)
             fpuAngle = -7.6   # degrees - chopper angle at which to calculate the delta position
             chopPos = fpuAngle2ChopPosPol(Double1d([fpuAngle]))
             offsetChopPos = convertChopperAngleSteps(chopPos,bluePhotSky * 80.69/60.])
             print offsetChopPos

Filter Wheel PHOT

• POS A = Long wavelength (Green)
• POS B = Short wavelength (Blue)

Filter Wheel SPEC

• POS A = Short wavelength (50-70um)
• POS B = Long wavelength (70-100um)

Calibration sources

• CS1
  • 48 Ohm = 55K
  • Chopper position center : -21350
• CS2
  • 58 Ohm = 60K
  • Chopper position center : +21200
• Temperature - resistance conversion:

  • Calsource_T_R_Conversion.txt (left column: Temp in K; right column: Resistor Value in Ohm)

Saturating OGSE BB temperatures

In the following tables you find OGSE Blackbody temperatures for which one can expect saturation in the spectrometer. The estimates are done for 0.25s ramps.

Blue detector

Red detector

It is assumed that the saturation level happens at 30,000 ADC/ramp.

When no temperature is given in the Table it means that it is above 60K.

XY stage

• Scale: 1" on the sky = 0.18mm
• Spectrometer
  • Focus : +5mm (from FMILT-1, not incompatible with spectro FMILT-2)
  • 1 pixel = 9.4" = 1.692mm
  • Center spectro field :

    • 	X stage (mm)	Y stage (mm)
      RED	-12.7628	0.938300
      BLUE	-12.6774	1.15180

• Photometer
  • Focus : +5mm (from FMILT-1)
  • 1 blue pixel = 3.2" = 0.576mm
  • 1 red pixel = 6.4" = 1.152mm
  • Center field :
    • x = 4 mm
    • y = 1.5