A joint DOE-NCI workshop on ion beam therapy (January 2013, Bethesda, MD) has identified an ambitious set of technological developments needed to support a world-class treatment program for ion beam therapy. One important requirement is the ability to provide detectors that afford single-particle registration at high data rates with high degree of uniformity and minimal interference with the particle beam. This would allow performing proton or ion CT prior to treatment and 2D proton, ion radiography during treatment for integrated range verification, and beam diagnostics that have minimal interference with the primary beam. The final workshop report stated "A better method of determining the stopping power, be it through proton CT or other means, would greatly increase the accuracy of the treatment, particularly when 1 mm range precision is desired. This is an important area for further R&D. We propose to develop a novel detector type, the plasma panel sensor (PPS), for proton and ion particle detection and imaging. The PPS is an inherently digital, high gain, novel variant of micropattern gas detectors inspired by many operational and fabrication principles common to plasma display panels. The PPS is comprised of a dense array of small, plasma discharge, gas cells within a hermetically sealed glass panel, and is assembled from non-reactive, intrinsically radiation-hard materials such as glass substrates, metal electrodes and mostly inert gas mixtures. Our approach is to perform the following specific aims for this Phase I SBIR proposal:
Specific Aim 1 : Test the feasibility and mechanical stability of a thin-glass PPS embedded in an external envelope by building a small prototype.
Specific Aim 2 : Define specifications for imaging with and monitoring of charged particle beams based on clinical needs.
Specific Aim 3 : Evaluate potential system performance with GEANT4 Monte Carlo simulations.
Specific Aim 4 : Develop design of a significantly higher resolution, larger area, thinner substrate Phase-II device based on the results achieved under Specific Aims 1-3
Fast and thin large-area detectors are necessary for state-of-the-art ion beam therapy to provide the means for proton and ion CT and radiography and to verify beam quality. Our solution, the plasma panel sensor (PPS), provides an attractive option for large-area detectors to be used in several different applications in a future ion beam research and treatment facility.