SPIcam - Quick Information and Specifications

Contact Webmaster for web page errors, corrections, ommisions, and/or additions.

This page last updated: March 7, 2007 - JMD
This page last checked: October 30, 2004 - JMD

Basic User's Guide: SPICAM- 2007

Instrument Description

SPIcam is an acronym for Seaver Prototype Imaging camera. We would like to acknowledge the generous support of the Seaver Institute and the David and Lucille Packard Foundation who made construction of this instrument possible. SPIcam is a general purpose, visible-wavelength, direct imaging CCD camera with > 50% QE between 400-900 nm. It may be operated in either traditional point-and-stare mode or in a drift-scanning mode.

The detector in SPIcam is a backside-illuminated SITe TK2048E 2048x2048 pixel CCD with 24 micron pixels and an unbinned plate scale of 0.14 arc seconds per pixel, giving a field of view of 4.78 arc minutes. Gain and noise have been measured (November 2003) at 3.36 +/- 0.50 e-/ADU and 5.7 +/- 0.1 e-. CTE was measured to be 0.999999 in both the serial and parallel directions. A linearity plot is available here

Approximate readout times for various binning values are as follows: 123 sec. (1x1), 40 sec. (2x2), 36 sec. (3x3). There is a ~6 sec. overhead period before shutter open time. Filter wheel moves take ~2-5 sec. each to complete.

User filters can be accommodated upon request and receipt of the shipped items at APO. Mounts for 3"x3" and 2"x2" square filters are available in-house; users desiring other filter shapes/sizes must provide their own filter mounts and should consult with APO staff in advance of sending hardware.

SPIcam Quick  Information and Characteristics

Detector

• CCD is a SITe/Tektronics TK2048E 2048x2048 back illuminated CCD
• CCD pixel size = 24 µm
• CCD Temperature: -103C
• CCD gain = 3.36 ±0.50e^-/ADU
• CCD read noise = 5.7 e^- / pixel ±0.1
• Full well depth: 216k e^- (measured)
• Linear up to 64k, Saturation at 64K, measured linear 99.9% @<=62K ADU
• Quantum Efficiency: (see table below)
• Dark Current: <1 e- / second

Resolving Power

• Pixel scale = 0.141"/pixel binned 1x1 (usually binned 2x2, 0.282"/pixel)

Spectral Coverage

• Installed filters (User selectable): Up to 6, 2" or 3" filters can be loaded by the Observing Specialist

Field of View

• Field of View: 4.78' x 4.78'

Minimum Exposure Times

• Minimum Exposure: = 0.76 seconds on up. (Reliable!)
• Warning, Exposures shorter than 0.76s will cause problems with SPIcam!!!
  If you mess the shutter up then issue the command "cecho SHINIT" from within SPIcam to fix it.

Sensitivity

• CCD Noise, Quantum Efficiency, and Linearity

SPIcam QE data

Filter	Max Noise (e-)	QE	(Å)	e- in Sky
u'...	7	0.36	3500	45
g'...	7	0.73	4700	400
r'...	9	0.82	6400	700
i'...	20	0.69	7700	1200
z'...	16	0.18	9200	1100

Table & Chart taken from The Astronomical Journal, 116:3040-3081, 1998 December