1. Radiation Resistant Camera Project status meeting, St Etienne, 7th and 8th of march 2016
Project lead by Fusion For Energy (F4E)
European Agency for ITER project
Elisa Guillermain

2. Project context F4E for ITER Remote Handling operations Tasks :
OTL for sub-components development
SCK for radiation testing
Components :
ISAE for the image sensor
UJM (Laboratoire Hubert Curien) for the optical systems (lens)
CEA for the illumination systems (LEDs)

3. Aim and requirements
Primarily : Diagnostic remote handling tool for welding and cuts.
Willingness to use it for other applications.
Foreseen characteristics :
Parameter
Minimum Requirements
Targeted Values
Minimum distance (mm) 10
Maximum distance (mm)
150
20000
Size (mm)
50x50x76
40x40x76
Mass (kg) 2 1
Radiation TID (kGy) 65
1000
Maximum temperature (°C) 50 70
Optical
System
Image
Sensor
Illumination
System

4. Sub-components : Image Sensor
CIS technology / CMOS Image Sensor.
Chips of 256x256 pixels.
Aimed is HD with 1280x720 pixels.
Color array is developed.
Tested up to 10 MGy in recent publication.
Tested at Gammas only.
Validation tests :
Electrical transfer function,
Dark current,
Saturation voltage larger than 500 mV,
Read noise below 1 mV RMS, …

5. Sub-components : Optical System
Working distance = 100 mm.
Field of view = 20 mm.
Glass choice :
Low Radiation Induced Attenuation (RIA).
Low Refractive Index Change (RIRIC).
Lenses under realization.
4 mm diameter lenses.
But need to develop testing tool for such small lens !

6. Sub-components : Illumination System
Off the Shelf LED.
Allow for low price
High luminosity, Small sized selected.
Two types :
Amber for monochrome sensor.
White for color sensor.
Tested with an integrating sphere.
Intensity, spectra…
Acceptance criteria:
Decrease of flux shall be less than 20%.

7. Project status overview
Validation of each sub-component.
Assembly of sub-components → Demonstrator.
Image acquiring : pre-irradiation reference.
Irradiation testing of all sub-components.
Gamma rays, 1 MGy. End 2016.
IS : Passive and Active tests (not image acquiring in active test).
OS : Passive test, Active test (RIA) is foreseen but to be developed.
IS: Passive tests, active tests are not foreseen.
Assembly.
Post-irradiation image acquiring.
Compare the image quality with pre-irradiation reference.

8. Project Follow-up Development plan & cost estimation to come.
Final camera integration.
Industrial partners.
Upgrade to focusing / zoom.
mandatory ? (depth of field…)
Or, foreseen at a later stage.
Proposal for Wavefront Coding.
Allow for a much larger depth of field.

9. Thanks for your attention !

10. Gamma Irradiation Tests : Image Sensor
Up to 1 MGy, steps (0.1 MGy, 0.5 MGy and 1 MGy), 0,5 to 1,5 kGy/h, end of 2016 (October).
Image sensor.
Offline test:
Image capturing,
readout noise, dark current, electrical transfer function, charge to voltage conversion factor, saturation level, responsivity…
Online test:
Half of the sensors grounded, half dynamically biased (sequenced).
Measure of the temporal average of the pixel reference voltages.
Info on the readout chain transistor health and functionality of digital circuits.
Acceptance criteria:
Dark current below 2 pA,
Saturation voltage larger than 500 mV,
Read noise below 1 mV RMS, …

11. Gamma Irradiation Test
Up to 1 MGy, steps (0.1 MGy, 0.5 MGy and 1 MGy), 0,5 to 1,5 kGy/h, end of 2016 (October).
Optical System.
RIA to be measured both offline and online (setup to be developed).
RIRIC to be measured offline.
Illumination System.
LED will be biased.
Offline test :
Flux and spectra measurement.
Online test not foreseen.
Acceptance criteria:
Decrease of flux shall be less than 20%.
Up to this value, the decrease can be compensated by increasing output power.

12. Other radiation resistance aspects
Mixed field particles irradiation test.
Not foreseen (foreseen application not in demand).
TID effect (i.e. dark current) are expected to be more important than neutron effects in CMOS.
Proposed to test the camera at CHARM. Set up a collaboration ?
Asses camera behavior under / during radiation.
Need for a reliable test.
Estimate of remaining lifetime.

13. Other camera characteristics
What will be the frame rate ?
25 fps targeted before irradiation.
Increase shall be possible up to 50 – 100 fps.
For higher speed, need dedicated development.
Will it blinded while exposed to gamma photons ?
Low dose rate.
Short exposure time (for a good dynamic range even with the high current level after irradiation).
Will not be checked at first irradiation test stage, but will later on.
When would it be ready for a test at CHARM ? (components, demonstrator…).
CIS and LED can be available.
Not optical system.