Laser-trapped atoms as a precision target for the storage ring TSR

We report on a new approach to transverse diagnostics of charged particle b eams by using a precision target of ultracold cesium atoms in a magneto-opt ical trap. The optically confined cloud of typically 10(4)-10(5) atoms has a diameter of about 100 mu m and can be positioned very precisely by using a weak static magnetic field. By scanning the position of the trapped-atom target over the ion beam and by detecting the ionization rate as a function of its position, we expect to measure the beam profile with unprecedented precision. We have realized such an ultracold target and characterized its properties in off-line experiments. (C) 2000 Elsevier Science B.V. All righ ts reserved.