Helmholtz Research Academy Hesse for FAIR


Measuring atoms

Coltrims (Cold Target Recoil Ion Momentum Spectroscopy) is an imaging technique for measuring the complete fragmentation of reactions with few particles involved. This is set up at CRYRING, a heavy ion storage ring.

All charged fragments from an atomic, molecular or surface reaction are projected onto large area detectors by a combination of electric and magnetic fields. From the measured time of flight of the particles and their impact position on the detector, the three-dimensional momentum vector is obtained, from which further conclusions can be drawn.

By cooling the target atoms (e.g. by laser cooling), a very high momentum resolution is made possible, which very few other experiments can provide.