Ion Detection Using Diamond Detectors

Detector grade carbon vapour deposit (CVD) diamond detectors can be produced either as polycrystalline wafers (up to 5" in diameter) or as single crystals with ! 1cm" area and > 1mm thickness. The free market prices for both types of detectors have now become affordable. While both types of detectors have unsurpassed timing properties as well as unsurpassed radiation hardness, a single crystal diamond detector in addition offers a superb energy resolution. The detectors can be stacked, and the contacts on both sides of these detectors can be evaporated in such a way that the detector setups are position-sensitive with a submm spatial resolution. All these properties are an exceptional advantage for ion detection: diamond detectors can be used for a wide range of ions (from protons to uranium), wide range of count rates (from single ion counting to more than 10 GHz), for a wide range of energies (from 100 keV up to GeV), and for a wide range of heavy-ion fluencies (more than 1013/cm"). The superb timing properties (20 ps rise time and slightly longer fall time of the electronic signals) are well suited for tracking and/or coincidence measurements. These extremely fast signals require, on the other hand, very fast sampling with more than 10 GHz and with a minimum of 8 bits (up to 14 for better resolution). Whereas diamond detectors can be operated continuously at very high count rates, the bottleneck remains the electronic read-out, since the total amount of raw data can easily reach 100 TB per day, and this is a formidable challenge for the data acquisition. (Note that in addition, the raw data have to be monitored and selectively filtered during the beam time.)