Here's the quick description: a metal framework sits on the benchtop. Various components are fastended to the framework. Some are cylindrical, some partly conical, some with flat ends, some with domed ends. All are connected to each other by metal tubes, though you can't see all the tubes in this photograph. You can keep reading the long version of the description, or you can return now to NICMOS photo.
The Brayton cycle, used in the NICMOS cooler, uses a gas (in this case, helium) which moves in tubes between the various sections of the cooler. When the cooler is installed in the Hubble Space Telescope, these components will be fastened to the parts of the telescope structure that best fit their functions. For testing in the laboratory, though, engineers designed a framework that sits on a benchtop and holds the cooler.
At the bottom of the framework is a flat base plate lying just above the benchtop. Rising behind this base plate is a vertical plate (with triangular support plates holding it up.) A narrow metal block emerges from behind the top of the vertical plate. Beams run horizontally from the top of the block. These beams stretch out over the horizontal base plate that's lying just above the benchtop.
One of the parts of the cooler has its top fastened to the horizontal beams and its base on the flat plate on the benchtop. This part is the recuperator, a tall, thin, shiny vertical metal cylinder. The recuperator is about 5 times as tall as it is wide.
A wider and shorter cylinder is mounted on the vertical plate, near the bottom. This is called the Compressor and Aftercooler. It's held onto the vertical plate by a ring of bolts through the flange on its base. The end next to the vertical plate is a silvery color, while the other end is more of a brass color.
The 2 pieces I've just described are connected by the plumbing. A metal tube leaves the bottom of the Compressor and Aftercooler unit (which is attached to the vertical plate.) The tubing runs past the the edge of the base plate, turns a right angle, runs parallel to the edge of the base plate, turns another right angle, and connects with the base of the recuperator, the tall vertical cylinder I described above. Partway along this plumbing, the tube has a section that's about twice the diameter of the rest. This thicker section is called the "compressor filter".
There are 2 units mounted on the horizontal beams at the top of the framework. They look pretty much the same to me (except that one has a filter on top.) However, they have different names: the one with the filter is the Circulator, and the one without is the Turboalternator. Both are shiny, polished, silvery metal. The general shape of these units is what you'd get if you took a cone, drilled a hole down the axis, then slipped a cylinder into the hole so that it stuck out at both ends. These units (not counting the filter) are each about a third or a fourth as tall as the recuperator. The filter is a cylindrical tank with domed ends. It is shiny metal and is about half as tall as the Circulator.
In the background is another labortory bench with a small research oven sitting on it. Beside the oven is a black looseleaf notebook.
Return to NICMOS photo.
This photo shows a version of the Turbo Brayton Cooler in which the components are widely separated. The various pieces are connected to each other by metal tubing. They're spread out on a table top in an area about 2 1/2 feet by 3 feet, most of which is empty. The components are all metalic. You can Return now or continue for the rest of the description.
Along the top of the picture is a cylinder about 2 feet long and a few inches in diameter. From its left end comes a tube which runs to the lower left corner of the picture. There, it connects to a cylinder about half a foot in diameter. We're looking down on the top of tyis cylinder, so it's hard to tell how tall it is.
That long cylinder at the top of the picture also has a tube coming out the right-hand end. That tube goes to the lower right corner of the photo, where it connects to a tiny component loops back up again. The tube then ends at another cylinder, a few inches long by a few in diameter. From this cylinder branch off another loop of tubing (with a small component in the middle) and a straight tube.
Return to photo of spread-out Brayton Cooler
This photo shows a compact arrangement of the Turbo Brayton Cooler, quite different in appearance from the previous picture (though the principals of operation) are the same. In the previous picture, all the components were spread out over the table top, connected to each other by metal tubing. In this version, the components are packed closely together. There are some short sections of tubing connecting two components to the central unit. You can Return Now or continue with the rest of the description.
The whole unit is about a foot tall. It sits on a clear plastic base about 8 inches in diameter. An oblong plate 2 or 3 inches wide runs the width of the base. One one end of the plate is a round metal piece about 2 inches tall by about 2 1/2 inches wide. On the other end of the oblong plate is a taller cylinder, 3 or 4 inches in diameter by 3 or 4 inches tall. From the top of this cylinder, a narrower cylinder sticks up another few inches.
Hanging off the central cylinder are 2 gold colored disks, about 1 inch thick by 2 or 3 inches in diameter. The disks are connected to the central cylinders by short sections of metal tubing.