Inelastic interaction of an electron with a C60 cluster

The method of intersecting beams of C-60 fullerene clusters and of electrons is used to investigate the production of C-60(+), and C-60(-) ions and the radiation in the wavelength range from 300 to 800 nm for the electron energy E-e ranging from zero to 100 eV. The absolute Values of the ionization and electron-attachment cross sections [sigma (+)(E-e) and sigma (-)(E-e), respectively] are determined. A maximum of sigma (+)(E-e) of 0.53 nm(2) is observed at E-e = 52 eV. For a C-60 cluster excited by electron impact, "delayed" (similar to 150 mus) ionization initiated by collision with the surface and ionization clue to thermionic emission (its characteristic time at E-e = 60 eV is 6 mus) is observed. It is found that, for E-e < 0.4 eV. the formation of C-60(-) is defined by the polarization capture of an s-electron (sigma (-) similar to E-e(-1)), and a formula is suggested for determining sigma (-)(E-e). In the legion of E-e from 1 to 6 eV, the cross section sigma (-)(E-e) shows only slight variations about sigma (-)(E-e)= 0.36 +/- 0.03 nm(2). For E-e > 7.5 eV, C-60(-) ions proved to be unstable to electron autodetachment. In the region of intersection of C-60 and electron beams. radiation of a quasicontinuous spectrum described by a modified Planck formula for the thermal emission of spherical particles of diameter d << lambda is recorded. For E-e > 47 eV. the brightness temperature proved to be 3150 +/- 50 K. It is found that this radiation is emitted predominantly by hot C-60(+*) ions produced as a result of thermionic emission from C-60(*). The rate of radiation loss of energy by a C-60(+*) ion and the cross section for the formation of radiating C-60(+*) ions are found to be, respectively, 5.5 x 10(5) eV/s at T = 3150 K and 2 x 10(-2) nm(2) at E-e = 60 eV.