Charged Particle Directional Spectrometers (CPDS) Most radiation detectors yield no information on the direction from which the incident particles come. CPDS has been designed to record this direction information. The EV-CPDS is a cluster of 3 CPDS units mounted outside on the ISS truss - click the image to the right for more detail. The IV-CPDS is a single CPDS unit and is used inside ISS.
Tissue Equivalent Proportional Counter (TEPC). TEPC uses a 2" diameter by 2" long cylindrical cell filled with low pressure propane gas. This hydrocarbon gas is used to simulate the hydrocarbon content of a human cell of 2 micron diameter. A plastic jacket covering the cell simulates the properties of adjacent tissue cells. Particles passing through the gas release electrons which are collected by a positively biased wire as a pulse. The characteristics of the pulse help identify the energy of the incident particle.
Passive Dosimetry (RAM, CPD) The Radiation Area Monitor or RAM is a small set of Thermo Luminescent Detectors encased in Lexan plastic. This material responds to radiation by exciting long-lived electronic states in various lithium (Li) compounds. After exposure, the amount of this radiation can be revealed by applying heat and measuring the amount of visible light released as these excited states decay. RAM units will be placed in scattered locations on ISS and will be brought to Earth for measurement after periodic Shuttle visits. The Crew Passive Dosimeter (CPD) is very similar and is carried by each member of the crew.
Passive Dosimetry, High Rate Dosimeter (HRD) The AN/UDR-13 Radiac Set is a compact, handheld, or pocket carried, tactical device capable of measuring prompt gamma/neutron dose from a nuclear event plus gamma dose and dose-rate from a fallout environment in a tactical battlefield situation. A push-button pad enables mode selection, functional control, and the setting of audio and visual alarm thresholds for both dose-rate and mission dose. A "sleep" mode with automatic wakeup is provided to enhance battery life. Data readout and warning/mode messages are provided by liquid crystal display. Features: Dosimeter capability of 1-999 cGy (neutrons/gamma-prompt initial and fallout) Ratemeter capability of 0.1-999 cGy/hr (gamma fallout) Settable alarm capability for dose and dose-rate Mission dose capability Digital readout Night visibility (secure lighting)