DynAMITe: a Wafer Scale Sensor for Biomedical Applications M. Esposito1, T. Anaxagoras2, A. Fant2, K. Wells1,

A. Kostantinidis3, J. Osmond4, P. Evans4, R. Speller3 and N. Allinson2

1University of Surrey, Guildford, U.K.2University of Lincoln, Lincoln, U.K

3University College London, London, U.K.4Institute for Cancer Research, Sutton, U.K.

The 9th International Conference on Position Sensitive DetectorsAberystwyth 12th - 16th September 2011

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Contents

•Biomedical imaging requirements

•Large area imaging detector with bimodal dynamic range and resolution

•Pixel structure and readout architecture

• Optical testing

• Conversion gain/ Read Noise/ Quantum efficiency/ FWC

• Charge collection test

• Non destructive readout- two separated readouts

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Large area imaging detectors

http://lemur.cmp.uea.ac.uk/ K. Lee et al., J. Bone Joint. Surg. Am. 2010;92:2709-18.

http://www.aesociety.org/

Large Area Detectors

Near real time frame rate

Flat Panel Imagers

• Large pixels

• High noise• Low frame

rate• ArtefactsCMOS APS

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Biomedical Imaging detectors

Large Pixels →High dynamic range

Small Pixels →Low NoiseHigh Spatial Resolution

Low NoiseHigh Spatial ResolutionHigh Dynamic range

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The DynAMITe detector

12.8 cm × 12.8 cm2 side buttable

Dynamic range Adjustable for Medical ImagingTechnology

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DynAMITe: sensor architecture

1260×1280 Pixels (P)100m pitch

Different reset voltages →

100 m

50 m

12.8 cm

12.8

cm 2520×2560 Sub-Pixels (SP)

50m pitch

Different depletion widths

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Single Pixel readout

Reset (S)P1

Reset (S)P2

Pixel

Select (S)P2

Select (S)P1

Out (S)P1Out (S)P2Frame rate

SPi @15 fps → SP @30 fps

Pi @45 fps → P @90 fps

Region of interest (100×100)SPi @370fps → SPi @740 fps

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DynAMITe: readout

Pixels

Sub-Pixels

Pixels & Sub-Pixels

Pixels & Sub-Pixels (ROI)

Sub-Pixels & Pixels (ROI)

Non destructive readoutOnline dose sensing

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Radiation hardness

38 MeV protons

1.5 MeV photons

A1

A2

B1

B2

C1

C2

D1

D2

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First images with DynAMITe

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Optical performance (Sub-Pixels)

Conversion Gain e-/DN 50.0±0.2Read Noise e- 149.9±0.7Full Well Capacity 105e- 2.8±0.2Quantum Efficiency % 45.2Dynamic Range dB 65.3Linearity % 65.2Integral Non Linearity % 0.4

523

nm

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Charge collection tests

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Non destructive readout (I)

timeS

igna

lS

P2

ResetSP1

SP1

T2 2×T2 3×T2 4×T2 =T1

SP2 sampled @ T2SP1 sampled and reset @T1

T2<T1

T2

2×T2

3×T2

4×T2

SP2

RE

SE

T

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Non destructive readout

ROI (SP2) sampled @ 26.3 fpsFull frame (SP1)sampled and reset @3.6 fps

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Conclusions•Dynamite sensor

• High dynamic range• Low Noise• High Spatial Resolution• Several readout modalities

•Optical characterisation (Sub-Pixel camera)• 45% QE• 150 e- read noise• 2.8 × 105 e- FWC

•Charge collection tests / Non destructive readout

•Future applications:• Radiotherapy portal imaging• Breast mammography• Diffraction imaging• Electrophoresis

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