Very large emissive foil detectors for the tracking of low-energy heavy ions

We present the development of a thin large-area tracking detector. The thickness of matter intercepted by the ions is approximately 0.25 mg/cm2 of low-mass material (aluminized Mylar). It is designed to detect low-energy heavy ions with a minimum of energy and angular straggling. We use a secondary electron emission foil coupled to an innovative large-area gaseous electron detector. The electrons are guided toward the detector by an electric and a magnetic field. We achieve good time (300 ps FWHM) and two-dimensional position (1.4 mm FWHM) resolutions over a large area (10×40 cm2).