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IDS Gratings with the 235 mm Camera

General Characteristics

There two available CCDs detectors for IDS are RED+2 (default detector) and EEV10, the pixel size and scale of the two detectors are:

  • RED+2 (default detector): 15.0 micron pixel with a scale of 66.7 pixels/mm and 0.44"/pixel, 2200 unvignetted pixels
  • EEV10: 13.5 micron pixel with a scale of 74.1 pixels/mm and 0.40"/pixel, 2275 unvignetted pixels (its use should be justified in the proposal).

    IDS gratings have a ruled area of 102 mm x 128 mm. A wide selection of gratings is available, and some of the important characteristics of each grating are summarised in the Tables below. The last two columns in these tables list as a reference, the nominal spectral resolution for a 2 pixel slit projected at the detector. The resolutions were calculated for 4500 Å or 7000 Å according to the blaze angle of the gratings.

    Grating changes are done during day time by support staff. Programmes that may need more than one grating per run should request this in the proposal.


  • IDS gratings' characteristics and parameters for Red+2
    Name1
    Blaze (Å)
    Max. Eff.2 (%)
    Dispersion3 (Å mm-1)
    Dispersion
    (Å pixel-1)
    Unvignetted range
    (Å)
    Slit 30μm (2 pix) at detector4 (arcsec)
    Resolution at 4500Å   for 2 pix at detector
    Resolution at 7000Å   for 2 pix at detector
    R150V B
    5250
    66
    271.3
    4.03
    8866
    1.03
    558
    ---
    R300VN
    5460
    72
    138.5
    2.06
    4532
    1.05
    1092
    ---
    R400BB
    3900
    50
    104.5
    1.55
    3410
    1.06
    1452
    ---
    R400VB
    5100
    72
    104.5
    1.55
    3410
    1.08
    1452
    ---
    R400RB
    7250
    59
    104.4
    1.55
    3410
    1.11
    ---
    2258
    R600RB
    6700
    65
    69.8
    1.03
    2266
    1.16
    ---
    3398
    R600IRB
    10000
    70
    70.2
    1.04
    2288
    1.19
    ---
    3365
    R632VN
    5460
    72
    66.5
    0.99
    2178
    1.11
    2273
    ---
    R831RB
    7500
    65
    50.7
    0.75
    1650
    1.27
    ---
    4667
    R900VB
    5100
    69
    46.4
    0.69
    1518
    1.17
    3261
    ---
    R1200UJ,5
    3500
    68
    35.3
    0.53
    1166
    1.15
    4245
    ---
    R1200B J
    4000
    76
    35.3
    0.53
    1166
    1.15
    4245
    ---
    R1200YB,6
    6000
    68
    35.2
    0.53
    1166
    1.33
    ---
    6604
    R1200RB
    8000
    66
    34.8
    0.52
    1144
    1.37
    ---
    6731
    H1800VP
    5300
    64
    23.2
    0.34
    748
    1.40
    6618
    ---
    H2400BJ
    4000
    60
    17.5
    0.26
    572
    1.37
    8654
    ---



    IDS gratings' characteristics and parameters for EEV10
    Name1
    Blaze (Å)
    Max. Eff.2 (%)
    Dispersion3 (Å mm-1)
    Dispersion
    (Å pixel-1)
    Unvignetted range
    (Å)
    Slit  27μm (2 pix) at detector4 (arcsec)
    Resolution at 4500 Å  for 2 pix at detector
    Resolution at 7000 Å  for 2 pix at detector
    R150V B
    5250
    66
    271.3
    3.66
    8327
    0.93
    615
    ---
    R300VN
    5460
    72
    138.5
    1.87
    4254
    0.95
    1203
    ---
    R400BB
    3900
    50
    104.5
    1.41
    3208
    0.95
    1596
    ---
    R400VB
    5100
    72
    104.5
    1.41
    3208
    0.97
    1596
    ---
    R400RB
    7250
    59
    104.4
    1.41
    3208
    1.00
    ---
    2482
    R600RB
    6700
    65
    69.8
    0.94
    2139
    1.04
    ---
    3723
    R600IRB
    10000
    70
    70.2
    0.95
    2139
    1.07
    ---
    3684
    R632VN
    5460
    72
    66.5
    0.90
    2048
    1.00
    2500
    ---
    R831RB
    7500
    65
    50.7
    0.68
    1547
    1.14
    ---
    5147
    R900VB
    5100
    69
    46.4
    0.63
    1433
    1.05
    3571
    ---
    R1200UJ,5
    3500
    68
    35.3
    0.48
    1092
    1.04
    4688
    ---
    R1200B J
    4000
    76
    35.3
    0.48
    1092
    1.04
    4688
    ---
    R1200YB,6
    6000
    68
    35.2
    0.48
    1092
    1.20
    ---
    7292
    R1200RB
    8000
    66
    34.8
    0.47
    1069
    1.23
    ---
    7447
    H1800VP
    5300
    64
    23.2
    0.31
    705
    1.26
    7258
    ---
    H2400BJ
    4000
    60
    17.5
    0.24
    572
    1.23
    9375
    ---


    [1] Prefix R for 'ruled grating' and prefix H for 'holographic grating'. The number following the prefix is the grating ruling (number of lines per mm). The suffix following the grating ruling indicates the range in which the grating is more efficient. The superscript character at the end of the name denotes de origing of the grating by following code:
    • B =Bausch and Lomb
    • N =National Physical Laboratory 
    • J=Jobin-Yvon PTR/NPL 
    • P=PTR replica from NPL master
    That is, a R150V grating is a ruled grating with low resolution, with 150 lines per mm, more efficient in the V-band (see that the blaze is at 5250 Å), made by Bausch and Lomb.

    [2] Absolute efficiency values measured at RGO.

    [3] At low and intermediate dispersions the dispersion changes little with the central wavelength.

    [4] Along the dispersion direction, the slit to detector reduction factor depends on the grating angle. This column gives the width in arcsec which projects to 30 (27) microns at the detector, when each grating is used close to its blaze wavelength. Note that 30 (27) microns is 2 pixels in the detector, hence this is the minimum required slit width according to the sampling theorem (e.g. for proper sampling, the wavelength resolution can not be less than about two pixels). If a wider slit is used to increase the total throughput, the wavelength resolution will be degraded.



    Grating Efficiency

    The efficiency of the gratings as a function of wavelength is shown in the Figures below.




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    Contact:  (IDS Instrument Specialist)
    Last modified: 20 August 2015