München 2004 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
MO: Molekülphysik
MO 12: Poster I
MO 12.26: Poster
Tuesday, March 23, 2004, 14:00–16:00, Schellingstr. 3
Combination of Supersonic Molecular Beam and Low Temperature 22-pol Ion Trap. Association of CH3+ + CO. — •Gheorghe Borodi1, Alfonz Luca1, Radek Plašil2, and Dieter Gerlich1 — 1Fakultät für Naturwissenschaften, Technische Universität Chemnitz, 09126 Chemnitz — 2Department of Electronics and Vacuum Physics, Mathematics and Physics Faculty, Charles University, 180 00 Prague
A low temperature radio-frequency 22-pole ion trap has been combined with a molecular beam for studying ion-neutral association processes at temperatures where an effusive gas inlet cannot be used due to condensation. CH3+ ions have been stored in 22-pole trap at 10 K and He buffer gas with number densities ranging from 3 × 1014 cm−3 down to 5 × 1010 cm−3. The pulsed supersonic beam of CO has been characterized via the N+ + CO charge transfer reaction. Within a width of 160 µs, the momentary CO number density in the trap was 1.7 × 1011 cm−3. Assuming ideal CO expansion the collision energy in the central of mass frame is 310 meV. For calculation of an effective temperature the remaining internal excitation of both reactants has to be assumed additionally. The collision complexes have been stabilized by the cold He buffer gas, reaching a temperature as low as 10 K. The ternary rate coefficient has been determined to be 8 × 10−25 cm6s−1. In order to further reduce the translational temperature in the beam experiment, the method of loading the beam with heavy rare gases is used.