Alice uses an array of
potassium bromide and
caesium iodide type of
photocathodes. It detects in the extreme and far ultraviolet spectrum, from wavelengths of light, with a spectral resolution of and a spatial resolution of per of altitude. Alice is intended, among its capabilities, to detect
ultraviolet signatures of noble (aka inert) gases including
helium,
neon,
argon, and
krypton. Alice should also be able to detect
water,
carbon monoxide, and
carbon dioxide in the ultraviolet. The instrument is powered using a radiation hardened version of an Intel 8052 micro-processor. The instrument uses 32KB of programmable read only memory (PROM), 128 KB of EEPROM, and 32KB of SRAM. The command and data handling electronics are contained across four circuit boards which sit behind the detectors. ALICE operates in two separate data modes; Pixel List mode (PLM) and Histogram mode (HM). In Pixel List mode, the number of photons/second are recorded. In Histogram mode, the
sensor array collects data/photons for a defined period of time. This data is then read as a 2D image. Furthermore, whilst the image is being read from the first memory bank, a second exposure can be started using the secondary memory bank. An advantage of utilising two different data modes is that the method of data collection can be tailored to the scientific goals. PLM provides time resolution, where as HM consistently requires same amount of memory, regardless of exposure length. ==Naming==