3D diamond detectors for small field dosimetry

In medical radiation dosimetry, small photon fields are almost a prerequisite for high precision localized dose delivery to delineated target volumes. However, such fields have inherent characteristics of charge particle disequilibrium and high-dose gradient, making dosimetric measurements challenging. A proposed solution for these challenging issues is the fabrication of diamond devices with 3-dimensional structures using laser pulses to create graphitic paths both in the surface and in the diamond bulk. By fabricating very narrow and close by columnar electrodes perpendicular to the detector surface, it is possible to create arrays of 3D pixels with very small sensitive volume. Furthermore, the project foregrounds a design methodology that allows overcoming the metal contacts problem using diamond surface graphitization, directly reducing the need for metallic components in the detector package. Hence, the aim is to fabricate a new highly segmented large all-carbon dosimeter able to obtain field profiles in a single measurement, reducing the uncertainty of the delivered dose and the need for correction factors.