Explore The Universe

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Featured Artifacts

High Resolution Imager (HRI)

Focusing X-Rays with Cylinders and Straws

X-rays either pass through or are absorbed by most substances, and they can't be focused with lenses or ordinary mirrors. But they will glance off a solid surface if they strike at a very shallow angle.

The orbiting x-ray telescope ROSAT used sets of wide metallic cylinders to "scoop up" incoming x-rays and focus them onto a detector called a High-Resolution Imager, or HRI. The x-rays ricocheted down the cylinders and into a bundle of microscopic metallic straws in the HRI. The x-rays knocked electrons off the sides of the straws, which channeled the electrons onto a fine wire mesh screen. The resulting electrical impulses were used to create an image showing the intensity and distribution of the x-ray energy.


HRIs (94k JPEG)

High Resolution Imagers

The high-resolution imager (pictured, top right) and microchannel plate (top left) are identical to the one on the Chandra x-ray satellite.
At bottom is a handmade prototype for a high-resolution x-ray imager.

Courtesy of Steve Murray, Smithsonian Astrophysical Observatory


Other Featured Artifacts in this section of the exhibit:
Hubble Space Telescope Wide-Field/Planetary Camera & CCD
Hubble Space Telescope Backup Mirror
Penzias and Wilson Pigeon Trap


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