Evidence for the HCl⁺(A) formation in the reaction of Ne(³P) with the size-selected HCl dimer using an electrostatic hexapole field

Penning ionization of Ne(³P) metastable atom with size-selected HCl dimer was studied by using an electrostatic hexapole field and chemiluminescence detection. We found that the HCl dimer can also produce HCl⁺(A) ions in the reaction with Ne(³P) just like its corresponding monomer reaction. The internal energy distribution of HCl⁺(A) in the dimer reaction is cooler than that in the monomer reaction, reflecting the third-body effect due to the other HCl in the dimer.