Nanoparticulate Coatings Enhance Ion Detection

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Project Summary A new thin film deposition technique for increasing the gain and sensitivity of existing microchannel ion detectors was proven in a previously completed NIH phase I. An increased Secondary Electron (SE) yield from these films was found to improve with ion doses of helium up to > 100 Coulombs/cm2 while the electron yield from the uncoated detector first surface decreased after 1 Coulombs/cm2. A NIH Phase II will use these films to vary elemental composition and morphology of the first surface to increase the first hit SE yield and to prolong the deposited layer lifetime. Detector testing will proceed with in-house ion and electron sources. Methods for putting these thin film coatings onto the sidewalls of the MCP (in addition to covering the front detector surface) should increase the detector gain and substantially prolong the detector lifetime of commercially available MCPs. We will emphasize use of the Zeiss Orion helium ion microscope at Rutgers to perform accelerated lifetime testing of the MCP pulse height, gain and first surface secondary electron yield from individual pores. Elemental composition change in the first hit area of the microchannel pore will also be determined by Nanoscale Rutherford backscattering within the Orion and will be correlated with the lifetime and yield measurement. The combination of the Zeiss Orion configured with the Ionwerks NanoRBS spectrometer should prove to be a crucial tool in detector physics. In addition the overall performance of the NanoRBS will improve when this spectrometer is retrofitted with newly enhanced MCPs from this phase II effort. .