Camera CCD in sviluppo allXUVLab per un esperimento su razzo, precursore dellesperimento UVC del Solar Orbiter Compact (72mm x 72mm x 50mm) Lightweight Fully vacuum compatible 4096 x 4096 maximum CCD format Three-stage Peltier cooler Two available thermal links between the CCD and the TEC (ΔT=-85°C/-60°C) Very low noise preamplifier stage (1.8 nV/ Hz r.m.s.)

Forme donda del CCD (fasi orizzontali in alto e verticali in basso) come appaiono ad uno strumento chiamato analizzatore di stati logici

Problemi dei rivelatori UV low UV sensitivity, unstable, not radiation hard, highly visible sensitive Photomultipliers CCD Photodiodes (a-Si, treated Si, Al) Photodiodes (a-Si, treated Si, Al) Micro-Channel Plates high voltage, hygroscopic photocathodes, unstable gain, operated in UHV low UV sensitivity, unstable, not radiation hard, highly visible sensitive high voltage, 110 nm, low fluxes, dark current

Ideal UV detector for space visible blindness very low noise high sensitivity to XUV photons chemical stability radiation hardness Requests

Specifiche per i rivelatori del Solar Orbiter Solar blindness < Operating temperature ± 50°C Frame rate 1000 s - 1 Frame format 2K 2K Pixel size < 20 m Radiation hardness 50 Krad Weight 1 kg Common specification requirements for the imaging and spectroscopic instruments for remote sensing are Photon fluxes ( counts/s/px) Imaging 10 3 Spectroscopy D spectroscopy 10 5 Photon fluxes ( counts/s/px) Imaging 10 3 Spectroscopy D spectroscopy 10 5

Rivelatori UV disponibili Photon Counting MCP + XDL MCP + APS MCP + CID Advantages Photon counting Solar blindness Radiation hardness Spatialised T amb Disadvantages Efficiency < 30% High voltage biases Weight Spatial resolution (centroid required) External electronics (to be shielded!) Charge integration None! CCD is not rad-hard

Alternativa: nuovi materiali fotosensibili E g = 5.5 eV dark current < 1 pA visible rejection (ratio ) high EUV sensitivity Highly radiation hard Chemical inertness Mechanically robust (high Young modulus) High electric charge mobility = fast response time Low dielectric constant = low capacitance Diamond & nitrides are appealing materials for the EUV photon detection. Their main properties are hereafter sumarized :

Rivelatori a diamante Device area: 6 6 mm 2 Thickness: 40 µm Grain size: 20 µm Sensitive area 4 mm 2 Interdigitated contacts spacing 20 m thickness 0.1 m electrode width 15 m No thermal annealing back contact 25 mm 2

Dark current

Stabilità e risposta temporale T off = 30 %

Quantum Efficiency [1] Naletto, Pace et al, 1994 [2] Wilhelm et al.,1995 [2] [1] Diamond efficiency Comparison with other detectors E. Pace et al., Diam. Rel. Mater. 9 (2000)

Diamond – Responsivity Dark room temperature V bias = 30 V

Our proposal: flip-chip CMOS imager Select the most appropriate sensitive material Exploit the advantages offered by the CMOS technology to fabricate system- on-a-chip detectors Join the best material and on-chip CMOS electronics by means of the consolidated flip-chip technology (applied to IR photon and particle detection) The idea

Diamond bump-bonded detector Incident radiation Open electrode CMOS imager Sensitive layer Pixel array 12.5 m

Applicazioni attuali alla fisica delle particelle

Advantages of flip-chip technology High responsivity Visible rejection Available technologies Frame format and pixel size in the spec On-chip read-out electronics Radiation hardness Compact detector (reduced weight) Low power consumption High frame rate Windowing EUV sensitive layers bump-bonded on CMOS imagers could have many appealing features, such as: