Time-of-Flight study of molecular beams extracted from the ISOLDE RFQ cooler and buncher

摘要

Molecular beams injected into the ISOLDE Radio-Frequency Quadrupole cooler and buncher (RFQcb), ISCOOL, have been studied under varying conditions using a new Time-of-Flight (ToF) detector. When a beam of molecules is injected into the RFQcb and interacts with the buffer gas, collisional dissociation processes may occur. In this study, two different beams of molecules, CO ~+ and N_2~+, were separately injected into ISCOOL, and two different buffer gases (pure helium or a 90:10 mixture of helium and neon) were used. The radio-frequency of the RFQcb was varied as the molecules, along with the fragments from the dissociation processes, were extracted from ISCOOL and studied using the new Time-of-Flight detector. The main finding of this work is that the rates for molecular dissociation within ISCOOL were very small for both CO~+ and N_2~+, with the largest rates found for CO~+.