Historic Information for Mosaic

Historic information Pertaining to Mosaic II CCD Imager

The 8 SITe 2Kx4K CCDs [1] for Mosaic II were tested in the Tucson CCD Lab in the 1970s. After assembly of the focal plane, the CCDs were taken to CTIO and installed in the dewar. We have modified the prime focus area, strengthening the pedestal and enlargening the cage doors. Mosaic II was installed on the Blanco 4-m for engineering tests on July 12-14 1999, and has been scheduled for general visitor use for subsequent semesters.

Previous CCD test data for 16 channel mode [2].

Previous CCD test data for 8 channel mode [3].

Alternate WCS solution for circa 1999-2000 [4] (zip file).

Commissioning pictures [5] taken in 8-channel mode (but note that the Mosaic is normally read out by 16 amplifiers, i.e. 2 per CCD).

Available tape drives [6].

Last updated: 05 March 2010

4-m MOSAIC II First Pictures

Taken on the engineering night of August 3 1999, by R. Schommer, C. Smith, R. Smith.
Click on the pictures for full frame versions

[7]
Figure 1: 10 sec V band exposure of Galactic nebula M8

[8] [9]
Figure 2: 10s and 180s Halpha exposures of the M16 nebula.

[10]
Figure 3: 20 sec V band exposure on Baade's Window. Clusters are NGC 6522 and 6528.

[11]
Figure 4: 500 sec V band exposure of NGC 6822 Local Group dwarf galaxy.

Mosaic II CCDs

Here are some test data for the Mosaic II CCDs, as measured by Tom Wolfe in the NOAO/Tucson CCD Lab. All have excellent CTE, dark rate less than 1 e-/pix/hour at -90C, and charge injection of 1-2 electrons if a reverse vertical clear is done prior to integration. When reading the QE figures, remember that the 4-m prime focus corrector does not transmit below 3300A.

CCD#	21	22	25	26	27	28	29	31
Gain e-/adu (8 us ) Amp A:	2.18	2.34	1.72	1.78	1.70	1.70	1.63	1.85
Gain e-/adu (8 us ) Amp B:	1.78	2.23	1.78	1.73	1.69	1.64	1.68	1.73
Noise e-(8 us dwell) Amp A:	5.4	5.4	3.8	4.0	4.0	4.1	3.4	4.4
Noise e-(8 us dwell) Amp B:	4.8	5.7	4.7	4.6	4.4	4.0	4.2	3.5
Fullwell Ke-:	90	69	82	80	63	64	63	83
QE % at 3000A:		9			8	9	9	8
QE % at 3340A:		18	19	18	17	18	18	17
QE % at 3650A:	48	51	44	49	46	48	48	46
QE % at 4050A:	65	69	72	69	65	69	67	69
QE % at 6000A:	82	85	89	88	84	88	86	85
QE % at 8000A:	61	70	71	70	69	68	69	70
QE % at 9000A:	37	42	40	53	41	39	39	41
QE % at 10000A:		13	10	11	11	11	11	12
# of full column defects:	0	2	1	1	2	0	1	0
# of partial column defects:	1	2	0	9	1	0	6	0

Previous CCD test data for 16-channel mode

Report, 2002-05-17 [12] (brief)

Full frame, unbinned, dual readout

CCD (1)	1a	1b	2a	2b	3a	3b	4a	4b
FITS section	1	2	3	4	5	6	7	8
Gain (e-/ADU) 22 Nov 2000 (2)	2.5	2.8	2.5	2.2	2.4	2.4	2.4	2.3
Gain (e-/ADU) 17 May 2002 (2)	2.75	2.86	2.84	2.30	2.45	2.37	2.53	2.37
Gain (e-/ADU) 08 May 2004 (6)	2.73	2.91	2.83	2.27	2.86	2.52	2.42	2.36
Gain (e-/ADU) Oct 2005 (2, 7)	2.81	2.95	2.88	2.34	2.9	2.56	2.56	2.39

Read noise (e-) 22 Nov 2000	5.9	7.2	6.5	5.0	8.6	11.5	8.1	6.8
Read noise (e-) 17 May 2002 (3)	5.97	9.4	7.0	5.06	7.1	10.0	8.3	6.2
Read noise (e-) 08 May 2004 (6)	5.79	5.63	6.17	4.68	8.78	8.10	5.78	4.99
Read noise (e-) Oct 2005 (7)	6.25	8.66	6.98	5.23	10.02	8.79	6.75	6.07

Nonlinearities 17 May 2002 (4)	~<1%	~<1%	~<1%	~<1%	~<1%	~<1%	~<0.8%	~<1%
Nonlinearities Oct 2005 (4)	~<1%	~<1%	~<1%	~<1%	~<1%	~<1%	~<1%	~<1%

Spurious Charge (ADU) 17 May 2002 (5)	N/M	~10	~5	~8	~10	~12	~15	~8

Full well (e-) 08 May 2004 (6)	130,000	125,000	91,000	87,000	77,000	81,000	70,000	71,000
Full well (e-) Oct 2005 (7)	>112,000	>118,000	86,000	89,000	87,000	97,000	67,000	67,000

CCD (1)	5b	5a	6b	6a	7b	7a	8b	8a
FITS section	9	10	11	12	13	14	15	16
Gain (e-/ADU) 22 Nov 2000 (2)	2.0	1.8	2.1	2.0	2.5	2.6	3.3	3.3
Gain (e-/ADU) 17 May 2002 (2)	2.03	1.95	2.24	2.13	2.63	2.79	3.35	3.49
Gain (e-/ADU) 08 May 2004 (6)	2.01	1.93	2.25	2.13	2.17	2.38	2.69	2.60
Gain (e-/ADU) Oct 2005 (2, 7)	2.01	1.99	2.22	2.13	2.17	2.39	2.66	2.77

Read noise (e-) 22 Nov 2000	7.6	7.0	8.3	7.2	5.0	5.6	7.7	7.6
Read noise (e-) 17 May 2002 (3)	7.1	6.8	14.6	8.1	6.05	8.1	8.7	8.7
Read noise (e-) 08 May 2004 (6)	5.23	5.49	5.85	5.73	4.35	5.17	5.90	6.08
Read noise (e-) Oct 2005 (7)	7.22	10.23	15.1	8.89	6.94	6.42	9.05	8.56

Nonlinearities 17 May 2002 (4)	~<1%	~<1%	~<1%	~<1%	~<1%	~<1%	~<1%	~<1%
Nonlinearities Oct 2005 (4)	~<1%	~<1%	~<1%	~<1%	~<1%	~<1%	~<1%	~<1%

Spurious Charge (ADU) 17 May 2002 (5)	~-5	~-5	~-5	~-5	~-2	~-2	~-5	~-5

Full well (e-) 08 May 2004 (6)	76,300	84,000	97,000	102,000	95,500	93,000	62,000	67,600
Full well (e-) Oct 2005 (7)	76,000	80,000	73,000	81,000	91,500	100,000	56,000	61,000

Notes:

1. When looking at a Mosaic image, the 8 lower segments are denoted from left to right (ccd,amp) 1a,1b,2a,2b,3a,3b,4a,4b. Across the top, from left to right: 5b,5a,6b,6a,7b,7a,8b,8a.

2. Gain measured from Transfer curve.

3. Read noise calculated from standard deviation of a bias frame × gain.

4. Nonlinearities are the width of the envelope of the count rate curve over a large part of the dynamic range of the detector. They include any variation in the light source and shutter effects, although the shutter delay has been removed to first order. These measurements are therefore an upper bound.

5. Spurious charge is charge that is injected into the CCD as a result of parallel clocking. It shows up as a slope in the bias level in the vertical direction, quoted here in ADUs from the top to the bottom of the unbinned image.

6. Measured in the La Serena lab after the installation of a new CCD #3. Full well was determined from the variance curve, noise from the overscan.

7. Measured in situ at Blanco prime focus, using flat field lights.

Previous CCD test data for 8-channel mode

Gain, Read Noise, and Full Well of Mosaic II CCDs reading in 8 channel (8a) mode.

Last updated: 31 August 2000

	Chip 1	Chip 2	Chip 3	Chip 4	Chip 5	Chip 6	Chip 7	Chip 8
Gain (e-/adu)	2.6	2.7	2.3	2.4	1.8	2.0	2.7	3.3
Read Noise (e-)	6.1 e-	7.8 e-	7.9 e-	7.8 e-	7.1 e-	8.0 e-	5.8 e-	7.7 e-
Full well (adu)	48000	34500	28000	29000	43500	52000	41000	21500