Hello! I see that in experiments at facilities like ISOLDE, they produce molecular beams at energies of tens of keV. If I understand it right, they first create the molecule as a positive ion, and using electric fields (and maybe magnetic for mass selection) they take the particle out of the source with an energy of a few keV. Then they neutralize the molecule in flight and then perform spectroscopy on the neutral molecule. I was wondering if there is a way to slow down a neutral beam with such high energy? I assume one can also slow it down before neutralization, but as far as I understand the neutralization process happens by collision with a certain gas, and at low energies these collisions would significantly change the properties of the beam (such as direction, energy spread or energy levels distribution), so I assume that is not an option?