Mauna Kea Infrared is manufacturing a Peter Onaka designed array and instrument control system specifically for control of large format, single or multiple array infrared astronomical instruments.
The system is scalable for arrays from as small as 256x256 to multiple array instruments with formats of 2048x2048. The targets of the development of the RedStar1 system was the 1024x1024 Aladdin style array made by Raytheon(SBRC) and the 1024x1024 and 2048x2048 format arrays made by Boeing(Rockwell). The system is capable of controlling mechanisms, heaters, temperature controllers and all aspects of a Facility Class astronomical instrument.
The Redstar1 array and instrument control system is a flexible and scalable system designed to control large format infrared array instruments. It is a SPARC based VME64 format system running under Solaris and utilizes multiple SHARC DSP(digital signal processor) boards for clocking and data acquisiton from the array. Instrument control can be accomplished via VME boards for motor control, position sensing and communtications. Mechanism control and sensing and temperature control can also be implemented using Ethernet controlled peripherals. A block diagram of the system is shown below.
Click on any block for more information.
 In order to achieve high speed and low noise some of the eletronics is mounted on the cryostat. These cryostat mounted electronics includes 8 channel preamplifiers, 8 channel A/Ds, 16 signal clock/bias boards and fibre interface boards. The system shown above is configured for high speed simultaneous readout of all 32 outputs of the Aladdin array. The digitized image data is sent back to the DSP boards in the control computer via dual 1Gbit fiber links providing ground isolation from the control computer. For images of the boards in the cryostat electronics select below:
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| 8 Channel Preamplifier Board |
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8 Channel A/D Converter Board |
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16 Channel Clock Bias Board |
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1Gbit Fiber Board |
Eurocard Backplane
The Sparc based VME style instrument control computer running Solaris
 The control computer is shown above. It contains, from left to right, a Themis SPARC computer in VME64 format, and two pairs of an Ixthos quad SHARC DSP board and an MKIR Fiber board. Many empty slots are available for motor control or other boards. A 9 Gbyte disc is shown on the right.
 Shown above are two separate 19 inch rack modules. The lower one is the HP power supply. The upper is a box housing the Lakeshore temperature controller and Lantronics terminal server. All Redstar1 systems inlcude the HP power supply. The contents of the upper box vary from project to project.
Power supplies
The Redstar1 system uses the HP model 66000A modular power supply. This is a high quality switching supply that affords high efficiency with low noise operation. Power supply cables are made with teflon coated wire with a neoprene jacket and neoprene overmolded jacket on the Mil-spec cylindrical connectors. The modularity of the power supplies makes it easy to configure for different systems and makes service trival.
Temperature Control
The Redstar1 system uses a Lakeshore 330s temperature controller for monitoring the cold structure and controlling the detector temperature. A low noise filter is included.
Ethernet Control
Many devices and mechanisms can be controlled over the ethernet such as servo motor controllers and temperature control units. The image above shows a Lantronics terminal server which provides 8 serial lines for control of three motors and one temperature controller in this application. This is attractive in cases where the control computer is desired to be far from the instrument.
Cold Feedthroughs
 The cold feedthrough ensures that the ribbon cables that connect to the array mount are cooled to avoid excess background radiation. The low conductivity of the 28AWG thick manganin wire and the epoxied, gold pin headers ensures that the wires are cooled to the shield temperature. These feed throughs have been tested for cooling ability with 28 gauge copper wires that we use for grounds as well. The feed through connectors are mounted on a stepped or tongue and grooved aluminum subplate. Cryo ribbon cables are plugged in from both sides.
Cryogenic Wiring Diagram
Cryogenic ribbon cables
 The cryogenic ribbon cables are made with 118 conductors of 28AWG manganin wire with 4 conductors of 28AWG copper wire for grounds covered in a extruded Teflon low outgassing ribbon. This style of cabling was selected based on low capacitance and low conductivity. Each end of the ribbon has a IDC (crimped connector) which makes the cable manufacture very simple.
Features
- 2 61 pin hermetic connectors
- 61 pin Bendix to 34pin IDC headers
- 64 pin DIN41612 connectors on array configuration board
- Cold Light tight feed throughs
- Manganin cryogenic ribbon cable
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| Science grade Aladdin Array in mount without shift register mask and baffle |
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Aladdin style detector mount with fiberglass V tabs for temperature isolation |
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View into the array mount with dummy detector in place |
Features of the array mount
- Compact size 4.0 x 4.0 x 1.65 inches
- 4 Heater resistors
- Lakeshore temperature sensor
- Mount light tight to <.1 e/s dark current
- Enclosed Faraday shield
- Low temperature baffle
- Cryo-ribbon cable connections
 Shown above is a sample of the Redstar1 screen output. The instrument control window is on the left and the image display and processing portion is the window on the right. More detailed software description is under construction.
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