Diamond ∆E-E telescope with an ultra-thin ∆E-diamond detector

Abstract

The limits of mechanical polishing and RIE/ICP etching process were investigated to reduce the thickness of detector-grade ultra-thin below 10 μm, preserving the high quality of starting single crystal diamond (SCD) material. Free standing electronic grade SCD films with sizes up 4.5 × 4.5 mm2 and thickness down to 5 μm with overall thickness uniformity of ±0.35 μm were fabricated. The ultra-thin films were flat demonstrating the low internal stress.Diamond ∆E − E telescope was made from 5 μm thick ΔE-detector and 500 μm thick E-detector. The telescope was installed at the MARS spectrometer (Cyclotron Institute, TAMU) and tested with 241Am and 228Th alpha sources and 20Ne ion-beam, demonstrating the good spectral resolution around 100 keV. Simulations with the LISE++ program indicate that the telescope will be suitable to measure low energy heavy ion beams at energies as low as 2–3 MeV/nu for Au and U heavy ions, and even lower energies for lighter ions. The diamond telescope will be superior to common Si radiation telescopes having a low life-time in intense heavy ion-beams.