120 Radiation Hard Imaging Detectors based on Diamond

1/20 Radiation Hard Imaging Detectors based on Diamond Electronics Marco Girolami 1, Arnaldo Galbiati 2, Stefano Salvatori 3 3 1 Department of Physics, Roma TRE University, Rome, Italy 2 Solaris Photonics, London, United Kingdom Department of Electronic Engineering, Roma TRE University, Rome, Italy S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

2/20 Radiation Hard Imaging Detectors based on Diamond Electronics INTRODUCTION This work reports on the realization and test of a compact diamond-based radiation beam profiling system: multistrip and pixel structures have been used for the realization of 1 D and 2 D position and imaging detectors, respectively. A dedicated read-out electronic circuitry has been designed and used to independently sample the signal produced by each strip (or pixel), enabling a real-time beam profile reconstruction. S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

3/20 Radiation Hard Imaging Detectors based on Diamond Electronics WHY ? can be operated at room temperature and are able to detect deep UV photons, X-rays, gamma rays, charged particles, M. I. P. and neutrons for a wide range of industrial and research applications as: particle tracking at CERN, beam conditions monitoring for synchrotrons and LINACS, radiotheraphy imaging, excimer laser beam diagnostic etc. S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

Alpha Spectrum with Diamond Radiation Detectors 4/20 WHY ? M. Pillon et al. , Nuclear Instruments and Methods in Physics Research A 640 (2011) 185– 191 S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

5/20 X-ray spectroscopy AMPTEK Cool-X source, double emission: • Cu Kα = 8. 05 ke. V • Ta Lα= 8. 14 ke. V Energy resolution (FWHM/Centroid): @200 V : 730 e. V @500 V : 900 e. V S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

6/20 UV and X-ray source imaging • VLSI-ULSI integrated circuits and MEMS lithography UV • Refractive eye surgery (LASIK) • Reflected UV imaging X-rays • Microanalisys techniques (EXMA, XPS, XRD, XRF) • Industrial radiography • Medical diagnostics and radiotherapy Focus: Real-time monitoring of beam shape and intensity S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

State-of-the art silicon beam profilers 7/20 CCD beam profilers for UV and X-ray source imaging: PROs: • well-established technology • good Q. E. for back-thinned devices • large area detectors CONs: • radiation damage • strong VIS-IR absorption • large dimensions, high cost It’s mandatory the use of: • attenuators (to limit radiation damage) • complex optical systems to improve UV-VIS discrimination Scheme of a commercial UV beam profiler S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

Why diamond? 8/20 The special characteristics of diamond allow its use in extreme environmental conditions like high temperature, high radiation, and highly corrosive environments. high carrier mobility (e. g. greater than silicon)-> ultra fast high radiation hardness-> High S/N ratio after radiation damage (e. g. : see oral N 7 -4) → no frequent replacements • Resistivity ~5 orders of magnitude > Silicon high break down field • transparency in the VIS-IR spectral regions • wide bandgap (5. 45 e. V)-> Low leakage current • highest thermal conductivity (22 Wcm-1 K-1)-> no cooling No need for attenuators and/or converters between source and DUT S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

Dark current and spectral photoconductivity 9/20 • Sandwich configuration (Ag) • Ohmic behavior up to 100 V bias • Low dark current (few p. A) • UV light: λ = 220 nm, PINC ≈ 1 μW • High quality sample • High UV vs. VIS selectivity • Low sub-bandgap conductivity • Low surface recombination S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

10/20 Response speed and linearity • Single laser pulses (Ar. F, 193 nm) • Rise-time ~ 1. 3 ns (VT) • Fall-time ~ 6 ns • Intensity-dependent pulse shape • Linearity up to a 5× 10 -3 m. J /cm 2 (trap-assisted recombination) • Band-to-band recombination prevails at higher energies (sub-linearity) S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

1 D and 2 D pixel detectors technology S 2 DEL - Solid State and Diamond Electronics Lab 11/20 SOLARIS PHOTONICS

Operation principle S 2 DEL - Solid State and Diamond Electronics Lab 12/20 SOLARIS PHOTONICS

Multichannel electronic system (32/64 channels) 13/20 Main features • Integration time: 50 μs ÷ 1 s • Selectable charge range: 50 p. C ÷ 350 p. C • Sensitivity: LSB < 15 f. C (150 p. C FS) • ADC resolution: 20 bit • Floating input ADC resolution: 14 bit • Selectable number of acquisitions: 1 ÷ 210 • Max. data throughput: 2 k. Hz (2∙ 64 k. SPS) • Math tools: centroid, mean value, displacement S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

UV position-sensitive detectors 14/20 • Centroid vs. displacement linearity • Spatial resolution: 5 μm (1 D), 20 μm (2 D) S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

UV 1 D beam profiling (32 channels) 15/20 Monochromatic UV source: • spot 5 x 5 mm 2 • λ = 220 nm • PINC ≈ 1 μW Sensor held on a micrometric moving stage (10 μm of resolution) M. Girolami, P. Allegrini, G. Conte and S. Salvatori – “CVD Diamond Detectors for Real-Time Beam Profile Measurements” – Proceedings of The 7 th IEEE Conference on Sensors, pp. 270 -273 (2008) S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

2 D detector for UV and X-ray source imaging S 2 DEL - Solid State and Diamond Electronics Lab 16/20 SOLARIS PHOTONICS

17/20 Excimer laser pulse beam profile: Ar. F 193 nm Closed shutter Single pulse “Ghost peak” Single excimer laser pulses real-time monitoring S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

Temporal evolution of UV deuterium lamp radiation 18/20 Deuterium 10 μW, 220 nm S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

X-ray beam profiles 19/20 Coolidge tube: • Mo target (Kα = 17. 48 ke. V, Kβ =19. 6 ke. V) • V = 45 k. V • I = 1. 1 m. A • spot-size 3 mm Displacement along X-axis S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

X-ray beam profiles 20/20 Displacement along Z-axis X-ray beam divergence increases with sourcedetector distance S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

21/20 Conclusions Diamond multistrip and pixel structures have been used for the realization of radiation hard imaging detectors with dedicated read-out electronics for real-time photon and particle beam profile reconstruction. • Integration time: 50 μs ÷ 1 s • Spatial resolution: 5 μm (1 D), 20 μm (2 D) S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS

22/20 Future Work Diamond radiation hard imaging detectors with dedicated fast electronics: 1. 6 GHz Amplifier+5 GS/s Digitizers APPLICATIONS: Time of flight Pulse shape analysis Spectroscopy/Pixel THANK YOU FOR YOUR ATTENTION ! S 2 DEL - Solid State and Diamond Electronics Lab SOLARIS PHOTONICS