Electron Yields and Escape Depths from Spacecraft Materials.
Secondary electron emission (SEE) characteristics and photoelectron yields were determined for several insulating materials used onboard a space shuttle. These materials are: kapton, teflon, spaceshuttle tiles, and space suit cloth. Secondary electron escape depth and photoelectron escape depth from kapton were calculated from the experimental data. Sternglass' theory and Dionne's method were used in the calculation. Some semiempirical theories of SEE and three-step theory of photoemission were reviewed. Pulsed beam techniques were used to reduce surface charging problems. Three (mu)sec pulses of electrons were used in SEE experiments, and 100 msec to 1 sec pulses were used in photoemission experiments. The maximum SEE yields of the materials studied range from 1.75 to 2.70. The secondary electron escape depth in kapton was calculated to be 55 (+OR-) 5 (ANGSTROM). All samples have photoyields lower than 1.0%. The photoelectrons excited by 21 eV photons have 87 (+OR-) 30 (ANGSTROM) escape depth in kapton.
- Pub Date:
- December 1986
- Physics: Molecular