Systematic study of the normal and pumped state of high efficiency diamond particle detectors grown by chemical vapor deposition

Abstract

The efficiency and charge collection distance ͑CCD͒ of nuclear particle detectors based on high quality diamond films grown by chemical vapor deposition ͑CVD͒ have been systematically studied as a function of the methane content in the growth gas mixture and for varying film thickness. The effects of preirradiation with ␤ particles ͑pumping͒ have been thoroughly studied. The results fully support a recently proposed model ͓Marinelli et al., Appl. Phys. Lett. 75, 3216 ͑1999͔͒ discussing the role of in-grain defects and grain boundaries in determining the charge collection spectra of CVD diamond films both in the normal and in the pumped state. The model allows us to quantitatively explain the dependence of CCD and efficiency on film thickness, giving a microscopic picture of the effects of preirradiation with ionizing radiation in CVD diamond films. The highest average CCD obtained is 145 m in a 160 m thick detector ͑corresponding to about 50% average efficiency͒, while the maximum value ͑about 70% efficiency͒ is close to 370 m. In addition, CCD is shown to be higher than film thickness and to monotonically increase with thickness, indicating margins for further improvements.

Development of Crystallographic Texture and In‐Grain Misorientation in CVD‐Produced Single and Polycrystalline Diamond

“…[16,19,20] Defects in diamond films may exist as dislocations, grain boundaries, and various other imperfections. [21][22][23][24] Typically, geometrically necessary boundaries (GNBs) and dislocations may accommodate lattice misorientations in a crystalline material. [10] Though the common perception in diamond growth is that the single-crystal or homoepitaxial diamond growth is accommodated, at best, by dislocations, it needs to be pointed out that such dislocations, based on their spacing, may constitute the GNBs.…”

Time dependent 14MeV neutrons measurement using a polycrystalline chemical vapor deposited diamond detector at the JET tokamak

“…12 For the polycrystalline CVD diamond produced in Rome "Tor Vergata" University high values of CCD ͑160 m͒ and (up to 70%) have been reported 13 demonstrating that these films are suitable for radiation detection. The standard electronics used for a CVD detector consists of a charge preamplifier, a shaping amplifier, and pulse height single channel or a multichannel analyzer.…”

Time-of-flight methodologies with large-area diamond detectors for ion characterization in laser-driven experiments

“…Nevertheless, in the case of the polycrystalline diamond detector a broader spectrum is obtained with the peak shifted to lower values of CCE. This effect is due to several factors: trapping recombination centers, dislocations and grain boundary defects of polycrystalline diamond as well as fluctuations of the charge generation process, as reported in the literature [ 21 – 23 ] .…”