The superconducting camera, SCAM, is an ultra-fast photon-counting camera developed by the

European Space Agency , owners = , headquarters = Paris, Île-de-France, France , coordinates = , spaceport = Guiana Space Centre , seal = File:ESA emblem seal.png , seal_size = 130px , image = Views in the Main Control Room (1205 ...

. It is cooled to just 0.3 K (three-tenths of a degree Celsius above

absolute zero Absolute zero is the lowest limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value, taken as zero kelvin. The fundamental particles of nature have minimum vibration ...

). This enables its sensitive electronic detectors, known as superconducting tunnel junction detectors, to register almost every photon of light that falls into it. Its advantage over a CCD ( charge-coupled device) is that it can measure both the brightness (rate) of the incoming photon stream and the colour ( wavelength or energy) of each individual photon. The number of free primary electrons generated per photon event is proportional to the photon energy and amounts to ~18,000 per electronvolt, and therefore if the device is operated in single-photon count mode the energy of each captured photon can be calculated in the visible-light range, where photons have energies of a few electronvolts, each generating >20,000 electrons. In a normal CCD, only one primary electron is generated per photon, except for very energetic photons, like X-rays, where a normal CCD can operate in a similar way to a SCAM.

References

European Space Agency: ESA's new camera will revolutionise the way astronomers observe the Universe

S-Cam 3, the detector
Infrared imaging Infrared telescopes Astronomy image sensors {{astronomy-stub