Publications; BInEPCP RAS

International Journal of Mass Spectrometry 181 (1998) 27-30

Cooling of direct current beams of low mass ions

V.Koslovsky^a, K.Fuhrer^b, A.Tolmachev^a, A.Dodonov^a, V.Raznikov^a,H.Wollnik^b
^aInstitute of Chemical Physics, Chernogolovka, Russia
^bII. Physikalisches Institut, Universitat Giessen, D-35392 Giessen, Germany

Int J Mass Spectrom 181 (1998) 27-30)
Received 5 June 1998; accepted 14 August 1998

Collisional focusing of low mass ions of 1-40 eV is investigated in a rf-only quadrupole. The final ion intensities and energies are monitored by an orthogonal-extracting time-of-flight mass spectrometer. It was found that in this energy range Na⁺ and K⁺ ions can be cooled and focused as well as Cs⁺ ions if the residual gas pressure in this “quadrupole beam cooler” is high enough that each ion undergoes several collisions.