For TeV energy superconducting linear accelerator (TESLA), it is foreseen to measure the beam profile with so-called wire scanners. A thin carbon fiber is moved through the beam and the number of scattered secondary particles is measured in correlation to the position of the wire. From this, a beam profile can be calculated as an average over many bunches of the beam. With strip detectors made from diamond, the beam profile can be measured online for single bunches. With two perpendicular arrays of strips on the front and the back side of the detector, the beam profile can also be measured in the X and Y direction. If fast electronics are used and the bunches are not too short, even a longitudinal profile in the Z direction can be obtained. We successfully tested a diamond detector in a heavy ion beam with bunches of up to 3/spl middot/10/sup 10/ O/sup 6+/ ions and in a beam of 10/sup 10/ electrons in bunches with a length of 300 /spl mu/m, as planned for TESLA. The fluence of 10/sup 15/ e/sup -//cm/sup 2/ or more by one of the bunches foreseen for TESLA corresponds to the irradiation a vertex detector receives during ten years of large hadron collider. The results of our measurements will be presented and discussed.