Journal of Vacuum Science & Technology A, Vol.23, No.1, 215-217, 2005
Design and construction of a semiautomatic temperature programmed desorption apparatus for ultrahigh vacuum
A computer-controlled system that allows acquisition of large volumes of temperature programmed desorption data under ultrahigh vacuum conditions has been designed and tested. The vacuum part of the system consists of a sample mounted on a rotation-translation manipulator. a shielded quadrupole mass spectrometer for the desorption flux measurement. and a collimated molecular beam doser for adsorbate delivery. The experiment involves a series of tasks: (1) dosing of the adsorbate onto the surface; (2) calibration of the mass spectrometer gain: (3) translating the dosed sample to the mass spectrometer position; (4) linearly ramping the temperature of the sample to acquire the desorption spectrum; and (5) cooling the sample. In the system described here. these tasks are accomplished automatically. As a result, the time needed for the experiment and the potential for operator errors are substantially reduced. The performance of the system is demonstrated for CCl4 adsorbed on gold-supported single wall carbon nanotubes. (C) 2005 American Vacuum Society.