Chandra X-ray space observatory - ACISlabel-150

The Advanced CCD Imaging Spectrometer (ACIS), formerly the AXAF CCD Imaging Spectrometer, is an instrument built by a team from the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

's Center for Space Research and the Pennsylvania State University for the ''

Chandra X-ray Observatory The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources 1 ...

''. ACIS is a focal plane instrument that uses an array of

charge-coupled device A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a ...

s. It serves as an X-ray

integral field spectrograph Integral Field Spectrographs (IFS) combine spectrographic and imaging capabilities in the optical or infrared wavelength domains -from 0.32 μm to 24 μm- to get from a single exposure spatially resolved spectra in a bi-dimensional region. Develop ...

for ''Chandra''. The instrument is capable of measuring both the position and energy of incoming

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

s. The CCD sensors of ACIS operate at and its filters at . It carries a special heater that allows contamination from ''Chandra'' to be baked off; the spacecraft contains lubricants, and the ACIS design took this into account in order to clean its sensors. Contamination buildup can reduce the instrument's sensitivity. Radiation in space is another potential danger to the sensor. , after 15 years of operation, there was no indication of a limit to the lifetime of ACIS. Another design feature of the instrument was a calibration source that can be used to understand its health. This allows for a measurement of the level of contamination, if present, as well as any degree of charge transfer inefficiency.

References

External links

ACIS website
by the

ACIS website
by Pennsylvania State University
The ''Chandra'' Proposers' Observatory Guide
by the Smithsonian Astrophysical Observatory Chandra X-ray Observatory Space telescope sensors {{US-spacecraft-stub