Previous Article
Next Article
Table of Contents

IR Array News (1Sep92)
(from CTIO, NOAO Newsletter No. 31, 1 September 1992)

Pt:Si. We have done some more tests of the Pt:Si plus echelle
combination (see Newsletter No. 27), this time in better weather, and
with both the folded Schmidt and long cameras. We have also
experimented with alternative cross- dispersers in an effort to improve
efficiency. We will continue to make this instrument set-up available,
but if there is little or no interest we may retire it in order to use
the dewar for lab tests of other arrays.

The Pt:Si dewar can be used on the echelle with either a standard J or
H filter. Changes from one to the other can be done during the day but
are not encouraged; contact Jay Elias for details.  The following table
gives some information on the properties of the instrument.


    Camera      Filter           Orders           Coverage
			         on Chip          per Order
    Long (R=33,000)
	    J(1.15-1.35 um)        1-2               45 A
            H(1.45-1.80 um)         1                60 A

    Folded Schmidt (R=12,000)
	    J(1.15-1.35 um)         4               130 A
	    H(1.45-1.80 um)         6               170 A


These values are all somewhat approximate. Sensitivity at H, with the
folded Schmidt, gives about 3:1 signal to noise in half an hour for
H=+7.3.  Sensitivity at J will be about a magnitude better, and with
the long camera about a magnitude worse. One should also note that the
coverage is, in all cases, less than the free spectral range of the
echelle (which is about 300 A at J and 500 A at H), so that even when
multiple orders fit on the chip, wavelength coverage is not continuous.

Anyone with questions about using this set-up should contact Jay Elias
(jelias@noao.edu).

HgCdTe. We have received the engineering grade NICMOS III array and the
bare multiplexer sample from Rockwell. Once resources permit, we will
start operating the engineering-grade array under Arcon; design of the
imager dewar for the science grade array should begin during the coming
quarter.  Watch the next Newsletter for information on availability.

InSb. We are extensively re-writing the instrument manuals for the IR
Imager and IR Spectrometer and will begin distributing them through our
Tucson office starting in late September or October (i.e. they will not
be available in time to help writing proposals). Users are reminded
that the software (and software manual) used for array control is the
same as that used at KPNO for the InSb instruments. Copies of the
software manual can be obtained through KPNO, although the CTIO office
will probably stock a limited supply.

Jay Elias, Brooke Gregory

Previous Article
Next Article
Table of Contents