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Status, March 30th, 2005

DBS Blue (Dewar 11) is now fully operational at SSO. Focus changes were made
during the recent return to RSAA. The camera was used for observing last week
and found to perform up to specification.

The old DBS Blue head will now be returned to RSAA and be re-fitted to run
as the new DBS Red camera, operating with a detector of similar specification
to the DBS Blue camera.

After the new red camera has been commisioned at SSO, in the 2nd week of May,
the old DBS Red camera will be returned and its operational use re-directed,
possibly for use on the Echelle, utilising the Engineering grade E2V 2kx2k CCD.
This device has more than adequate performance for this use.

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Status, March 16th, 2005

The DBSB head has now been fully tested and is ready for return
to SSO on Saturday. Focus adjustment has been completed and the
detector read-noise and spectral response characterised. Believed
to be good to 5-10%

Read-noise is still 3.5e with the new, long ARC to Dewar cable
permitting the 2 parts to be mounted separately.

The complete optical waveband QE has been measured and is presented
in the accompanying figure

Spectral Response for DBSB, E2V 20-1 CCD.

The old DBSB head will be returned at the same time so that this _can_ be used
if any problems occur. This WILL require the optical window changing and so
will not be available for 24 hours. This is NOT expected to happen however!!
The old DBSB head will be returned again to RSAA in 2-3 weeks, when it will
then be re-fitted as the new DBS Red head.
The turn-around is expected to be about 4 weeks.

This will then complete the SII refit of all the old cameras with newer, faster
lower noise E2V detectors.

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Status, March 14th, 2005

The DBS head was returned to RSAA for a focus shift change.
This has meant moving the DMB (Detector Mount Block) rearwards
in the dewar, by about 2mms. The preliminary tests on the 3rd March
indicated that this was required and that it should be done at RSAA.
Further it has been decided that the ARC controllers for the DBS
cameras will be moved from the head, to their own mounting on the
DBS itself. This is to remove any possibility that the excess weight
could cause any more damage to the optical window, when mounting the
camera in the DBS focus port.

Changes to System settings

In addition, I have changed the default Read-out timing to allow
the lowest noise possible to be achieved from the CCD.
This has been measured here at RSAA to be 3.5e rms
resulting in a read-out time of 7 seconds. See the following table
for a summary of the operational parameters tested to determine the new
read-out speed and sample time.

Sample time 1us, R/O time 3s
Cicada	CDS Gain	Integrate	System Gain	Noise(e)	Comment
GAIN		Speed(us)	(e/adu)
0	9.5	1	0.43	19	HI Gain - Noisy - Do not use
1	4.75	1	0.93	3.89	Useful
1	4.75	4	4.89	6.5
2	2	1	2.1	4.4	Default for Imager
3	1	1	4.4	5.8	LO Gain
Sample time 2us, R/O time 7s
1	4.75	1	0.45	9	HI Gain
2	2	1	1.04	3.5	BEST DBS - Bias=1230
3	1	1	2.35	4.65	LO Gain - Bias=1241
Sample time 4us, R/O time 12s
0	9.5	4	0.59	31	HI Gain - Noisy - Do not use
1	4.75	1	0.23	8.3
1	4.75	4	1.22	3.5	Useful for DBS
2	2	1	0.54	20
2	2	4	3.0	4.7
3	1	1	1.06	3.55	Useful for DBS
Sample time 8us, R/O time 21.5s
1	4.75	4	0.69	8.5
2	2	4	1.41	3.5

DBSB will be returned to Siding Spring for observational use on
Friday 18th March, utilising 2us sampling,
Gain 1.04e/adu, R/O noise 3.5e, R/O time 7seconds.

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Status, February 23rd, 2005

The DBS science camera will by trialed at Siding Spring at the beginning
of March. Mike Bessel has agreed to take the head and mount the camera on DBS
to perform preliminary focussing and observing tests. This will allow us
to determine whether the system is in focus. The DBS Detector mount has
to be carefully set by moving the whole detector assembly in the dewar
to achieve optimum focus. This can only be done by warming the head up
releasing the vacuum, moving the Detector mount by a fraction of a mm
and then pumping and cooling the head and testing again. This whole process
could therefore take days to get correct... It may of course be in
perfect focus straight away..... PMF :(|)

Current figures for the Spectral Response indicate (to +/-10%)

Wavelength(nm)	QE(%)
350	(84)
380	78
450	95
505	94
570	95
600	82
655	76
700	73
750	62
810	57
840	41
910	25
970	13
1050	2.5
Read noise 4.5e	Read out time 4secs !

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Status. February 7th, 2005

All the Optical componenents have now been installed after initial testing of the Science CCD
at room temperature. DBS Blue will now be set-up and characterised before delivery to Siding Spring
See details below for DBS-B Science camera build, last week.

Status. December 21st 2004

Work has now advanced to the stage of Engineering CCD tests for the DBS Blue camera

The picture above shows DBS with the old Blue and Red cameras installed. A new E2V, 0.5kx2k CCD is being fitted to the old TEK Imager - for use at the DBS Blue focal station. This detector is an E2V, thinned imager, anti-reflection coated and optimised in the Blue using the E2V 'Astro-B' coating. A similar device will be used for DBS Red but having a red-optimised AR coating.

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Test Image from Science grade DBS CCD

The image below was taken on Friday, 4/2/2005 with the DBS Blue Science grade CCD at -100C.

DBS Science grade CCD FITS data.

The frame shows a zero exposure, LED preflash (t=80ms) frame, again illustrating how the CCD format looks.
The CCD image area has 2048x512 pixels and the frame size is 2148 x 562. The X, under and overscans and
the Y overscan can be clearly seen. The iimage appears clean and free from defects - though there is
a small, out-of-focus hair in the top right-hand corner of the image.
This is almost certainly on the inside of the lens at the front of the cmaera
and will be removed when the dewar is next at room temperature. (see the attached FITS file).

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Assembly Of Optical Components and Science CCD in DBS-B

1. Science detector mounted on Detector mount block,
cover slip still in place.

2. Another view similar to above.

3. Close up view from side showing calibration LEDs.

4. DMB from front showing Science CCD and field flatener lens installed.
A steady hand was required here as the optical component sits on the outer frame of the CCD package!

5. Similar to above - shown form the side.

6. Close up of the Science CCD and its Field Flatener lens.

7. Complete internal mounting - DMB, Science CCD, Field
flatener lens and Temp. servo components. Shown from the side.

8. Close up of front of dewar showing dewar window with
retaining tape and into the dewar showing Science CCD and field flatener.

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Test Image from Engineering grade DBS CCD

The image below was taken today (22/12/2004) with the Engineering grade DBS CCD at -100C.

DBS Eng. grade CCD FITS data.

The frame shows a zero exposure, LED preflash (t=80ms) frame, illustrating how the CCD format looks.
The CCD image area has 2048x512 pixels and the frame size is 2148 x 562. The X, under and overscans and
the Y overscan can be clearly seen. In addition, there are several chip defects - one in the bottom right-hand
corner - a cluster of bad pixels and to the right of this, a column defect. There are 1 or 2
more pixel defects in the frame (see the attached FITS file).
For an Engineering grade CCD this is of quite good quality!
The Science array will be installed in the first few weeks of the new year.

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Documentation Available

E2V 4210 AIMO CCD for DBS.

The one we actually use in DBS is a Non Inverted Mode device

E2V 4210 NIMO CCD for DBS.

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Assembly & CCD Controller Hardware

1. Looking into dewar during construction showing LN2 can.

2. Detector mount block and Flex connectors.

3. Detector mount, PCB and Flex connectors.

4. Liquid Nitrogen can and cold strap mounting blocks.

5. CCD wiring - D type connectors and temperature servo

6. Detector mount block and socket installed in dewar.

7. Detector mount block - similar to above.

8. Detector mount block - showing calibration LEDs.

9. Detector mount block and 'nose cone'.

10. Close up of rear of detector mount block.

11. Another view of close up of rear of detector mount block.

12. Yet another view of close up of rear of detector mount block.

13. Rear view of DMB showing temp servo componenets (heater resistors and DT471 sensor).

14. Preparing to install nose cone'.

15. Nose cone installed. Preparing to install window.

16. DBS Blue mounted on QE Test Box with extender ring.

17. Front of BDSB dewar showing temporary fixings for window.

18. ARC Clock Generation Card.

19. ARC 250Mhz Fibre Optic Timing Card.

20. ARC Utility Card.

21. ARC dual channel Video processor Card.

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Enquiries about the 2.3m DBS Blue camera?
detman@mso.anu.edu.au

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