CRIRES User Manual
Doc. Number: ESO-254264
Doc. Version: P109.4
Issued on:
2021-12-01
Page:
15 of 99
Document Classification: ESO Internal Use [Confidential for Non-ESO Staff]
Figure 6: The original CRIRES detector mosaic focal plane array area compared to the new
detectors with an increase of a factor of 2.7 in the cross-dispersion direction.
Figure 7: The 3 CRIRES H2RG detectors are shown (right) together with the detector mount
(left)
3.1.4 The cryogenic vessel
CRIRES is located at the Nasmyth B focus of VLT-UT3. The instrument is mounted in a 3
m-diameter, 1 m high vessel. Including its support structure, the total weight of the
instrument is 6.2 t, spread between 2 t for the warm part or AO system and 4.2 t for the cold
part. The optics inside the cryo-vessel is cooled to 65 K. The detectors are stabilized at 35
K within ~5 mK
.
3.1.5 The CRIRES metrology concept
In order to stable exposures with high repeatability, the concept of a metrology system was
developed to allow for a 0.1-pixel
reproducibility. The strategy is to centre a defined set of
emission lines of the Kr and Ne pen ray lamps on the science detector by finetuning the
oCRIRES Aladin detector
mosaic 4096 x 512 pixels,
27 microns pixel size
Current Hawaii2RG detector
mosaic 6144 x 2048 pixels,
18 microns pixel size