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Multi- colour sctintillator -based ion beam profiler. James Green , Oliver Ettlinger , David Neely (CLF / STFC) 2 nd Ion diagnostic workshop June 7-8 th. Talk outline. Diagnostic outline Multi-channel characterisation Reducing EMP & radiation effects Demonstration on Astra Gemini
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Multi-coloursctintillator-based ion beam profiler James Green, Oliver Ettlinger, David Neely (CLF / STFC) 2nd Ion diagnostic workshop June 7-8th
Talk outline • Diagnostic outline • Multi-channel characterisation • Reducing EMP & radiation effects • Demonstration on Astra Gemini • Future developments
High-repetition rate advances • Passive media (CR-39, RCF, Image plate) increasing unsuitable • Transition to active diagnostics: Scintillators, Micro-channel plates (MCPs), Phosphor screens Scintillators Target Lens Radiochromic film (RCF) CCD Ionbeam Laser Fibre bundle Micro-channel plates (MCP)
2D detector head development 90 mm 100 mm • Diagnostic aims: • 2D beam profiling • Spectral measurement • Beam pointing • Calorimetry • Compact scintillator beam head • Scintillator thickness determines energy observation window • Each scintillator has a separate central emission wavelength • Need to avoid optical excitation within scintillator stack Detector head Scintillator 2 (Green) Scintillator 3 (Blue) Scintillator 1 (Orange Incident Protons Proton stopping ranges
Optical Stimulation • Optical Stimulation: • Emission from Blue or Green scintillators can optically stimulate emission from scintillators earlier in the stack • How to stop light travelling back through the system? Scintillator 2 (Green) Scintillator 3 (Blue) Scintillator 1 (Orange Incident Protons
Reducing EMP / radiation impact • High resolution 800 x 800 fibre bundles • Image relay from Phosphor / Scintillator to camera outside interaction chamber • Durable with flexible deployment options • Wide transmission range • Long fibre lengths (> 5 m) possible • Eliminating background radiation • Gated CCDs to block X-ray / electron signal • CCD safely shielded from hard hits Optical Core Optical Cladding Core 60um Groups of fibres inside bundle 60um
Channel separation Green Red • Signal split in front of camera into 4 channels, RGB + Extra • Dichroic filters used to isolate each scintillator signal Data obtained using from SRIM – http://www.SRIM.org All channels Blue
Data Deconvolution • System characterised using a Cyclotron proton source • Produced a response matrix for each colour channel • Predicted Response Matrix • Ideally require 1 on the diagonal, • with 0 everywhere else
Astra Gemini experiment • Astra Gemini – • 12J 50fs • 5x1020 Wcm-2 • >1010 contrast • TCC – Scintillator = 20 cm 1 - 4.5 MeV 7-9 MeV 10.5 - 14 MeV Scintillator 2 (Green) Scintillator 3 (Blue) Scintillator 1 (Orange Laser Incident Protons
Astra Gemini experiment • Shot a range of Al foils, 25-900 nm • Clear signals on orange and green channels, insufficient flux for blue • Clear structure visible with peak off axis for some shots 1- 4.5 MeV 7-9 MeV 10.5-14 MeV 50 nm Al 100 nm Al FOV = 30o
Imaging novel targetry RCF • Microspoke targets shot on Astra Gemini • Proton beam imaged using RCF and Scintillator stack Scintillator 1mm Disks: 32um diameter, 40nm thick SiN membranes Supporting wires: 1µm wide , 40 nm thick Hole etched through 400μm thick Si.
10 Hz operation • Scintillator considerations: • Rapid (s) recovery between shots • Minimising high dose damage • Implement new Scientific CMOS camera • 30 fps continuous full-frame operation • Low noise read-out, 16-bit Dynamic range • Data analysis • Real-time data deconvolution for live beam profiles (Desirable – looking for collaborators?)
Future developments • Further diagnostic testing • 0.05 Hz to 10 Hz progression • Efficient data capture and analysis • Scintillator development • Thin scintillators for high spectral resolution • Calibration at higher (> 30 MeV energies) • Faster scintillators for fast gating • Media lifetime • Experimental & industrial collaborations • Experimental access on range of facilities • Next-gen imaging and scintillator technology