A Fast, Direct Procedure to Estimate the Desorption Energy for Various Molecular Ices of Astrophysical Interest

Desorption energy is a relevant parameter when studying the desorption kinetics of an ice under astrophysical conditions. Values reported are generally calculated using at least a desorption experiment and a further data analysis at present. In this work the establishment of a simple rule that relates the desorption energy of a species to the temperature of its desorption peak is explored. The paper presents the results obtained from zeroth-order desorption experiments, based on the use of a quartz crystal microbalance to monitor the loss of weight during desorption of the accreted ice sample under high-vacuum conditions, of nine different molecules covering a wide range of desorption energies. During these experiments, the ice desorption rate reaches a maximum at a certain temperature depending on the molecule. The formula obtained in this study facilitates the estimation of the desorption energy and is valid for all the investigated molecules. Based on these experimental results and simulations, the theoretical expression obtained is valid to calculate desorption energy for zeroth- and first-order desorption experiments under high-or ultrahigh-vacuum conditions using different ice thickness films.