Boeing Radiation Effects Laboratory

	Combined Radiation Effects Test Chamber (CRETC)

The CRETC - Looking into sample exposure chamber
Type of Simulator	Charged particle accelerators with solar and vacuum UV
Application	Natural space radiation effects; materials studies, especially for spacecraft; evaluation of selected optical properties in situ; general studies. Produces combinations of electrons, protons, UV and other radiation types when required in order to reproduce the multifaceted nature of radiation encountered in the space environment.
Test Object Size	In the vacuum, generally up to 3" diameter; somewhat larger for electrons.
General Description	Boeing's "CRETC 2" is a 2nd generation clean chamber providing space-qualified samples and materials in vacuum test environment free of oils, vapors, and other contaminants which tend to distort the measured optical and thermophysical properties of such materials. Cryo and ion pumping are used to minimize these contamination effects. Irradiation of specimens occurs in target zones and closely simulates on-orbit conditions. Without disturbing samples, irradiation can be suspended and reflectance or transmittance may be measured from 250 nm to 2600 nm wavelengths in situ. Interchangeable electrical, dielectric, and mechanical property testing modules also exist. Prototype " CRETC 1", consisting of a 3 ft. diameter x 9ft. long vacuum test chamber remains at BREL to accommodate larger objects.
Technical Characteristics	Beam current	picoamps to nanoamps scattered over relatively large samples.
	Irradiation rate
	UV	from less than 1 sun to ~16 suns
	protons and electrons	variable to approximately a 100-fold acceleration of space exposure rates.
	Energy range
	VUV	1 to 11 eV
	protons and electrons	~15 to 50keV in CRETC 2
Instrumentation & Data Collection	Integrating-sphere reflectometer not requiring detachment and potential loss of samples. Static extensometer measuring mechanical strength during irradiation. Charge storage and arcing properties equipment including contactless electrometer and high-performance oscilloscopes. Solar cell I-V and other small-signal electrical property measurements apparatus. Automatic data storage and retrieval in near real-time.