Magnetic trapping of SH radicals

Phys Chem Chem Phys. 2017 Mar 28;19(12):8423-8427. doi: 10.1039/c7cp00458c. Epub 2017 Mar 13.

Abstract

Magnetic trapping of SH radicals, produced via the photostop technique, has been demonstrated. H2S in a skimmed, supersonic molecular beam was photodissociated at 212.8 nm to produce SH inside a 330 mK deep static magnetic trap. The molecular-beam speed was controlled by the mixing ratio of H2S in Kr to match the recoil velocity of the SH photofragments such that some SH radicals were produced with near-zero laboratory-frame velocity. The density of SH radicals in the 2Π3/2, v = 0, J = 3/2 state was followed by (2 + 1) REMPI over seven orders of magnitude of signal intensity. 5 ms after photodissociation, SH radicals moving faster than the capture velocity of 13 m s-1 had left the trap. The 1/e trap lifetime of the remaining SH radicals was 40 ± 10 ms at an estimated density of 5 × 104 molecules per cm3. Photostop offers a simple and direct way to accumulate absolute ground state molecules in a variety of traps.