NP SBIR-STTR Exchange Meeting g g Compact and Efficient Cold and - - PowerPoint PPT Presentation

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NP SBIR-STTR Exchange Meeting g g Compact and Efficient Cold and - - PowerPoint PPT Presentation

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NP SBIR-STTR Exchange Meeting g g Compact and Efficient Cold and Thermal Neutron Collimators DE-FG02-08ER86353 Program Manager: Dr. Manouchehr Farkhondeh g g Office of Nuclear Physics U.S. Department of Energy October 25, 2011 NOVA

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NP SBIR-STTR Exchange Meeting g g Compact and Efficient Cold and Thermal Neutron Collimators

DE-FG02-08ER86353

Program Manager: Dr. Manouchehr Farkhondeh g g Office of Nuclear Physics U.S. Department of Energy

October 25, 2011

NOVA Scientific, Inc. ,

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STTR Project Goals

Develop a compact MCP-based 2-D neutron collimator

  • Improve neutron beam parallelism and quality pre-sample; reduce

beam divergence and image blur at the detector

  • Reduce post-sample scattered neutrons into detector in a very

Reduce post sample scattered neutrons into detector, in a very compact space (only a few mm’s thick)

  • Computer-controlled alignment system

Criteria: Rocking curve sharpness Maintain > 50 % neutron throughput Maintain > 50 % neutron throughput, (even at extended L/D) Improved hi-resolution neutron images

NOVA Scientific, Inc. 2

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Microchannel Plate (MCP) Formats

(Examples shown used for particle detection) (Examples shown used for particle detection)

NOVA Scientific & the University of California-Berkeley Space Science Laboratory now adapting this technology for compact 2-D neutron y p g gy p collimation

S courtesy Photonis USA

NOVA Scientific, Inc. 3

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MCP Structure

Typical Diameter 8µm on 10µm centers Typical Diameter 8µm on 10µm centers

NOVA Scientific, Inc. 4

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10B and Gd neutron Absorption versus Neutron Energy

NOVA Scientific, Inc. 5

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Advantages of 2-D MCP-Based Collimation

 Very compact imaging setups can be implemented with

the MCP collimator devices Long flight paths no longer the MCP collimator devices. Long flight paths no longer required between the aperture and the detector.

 Some beamlines limited in space can greatly benefit;  Some beamlines, limited in space, can greatly benefit;

enables high resolution tomography and radiography even in a very constrained experimental setup space.

 Collimation with compact devices substantially improves

resolution for ‘large’ (few cm and larger)

  • bjects,

especially in tomography where objects may be rotated and therefore placed at a distance from the detector active area. active area.

NOVA Scientific, Inc. 6

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Computer Modeling

 Very powerful tool for MCP collimator design; has

predicted collimator test data with very high accuracy p y g y

 Avoidance of numerous lengthy and highly expensive

glass chemistry design and fabrication runs.

 Parameters in the model: glass composition (10B or Gd

doping levels), geometry (pore L/d and diameter)

 Output:

  • rocking curves
  • neutron transmission
  • out-of-angle rejection

NOVA Scientific, Inc. 7

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Experimental Campaign

 Multiple test runs have been carried out and are

continuing using several improved MCP continuing, using several improved MCP collimator test samples.

 Tests include both neutron beam shaping and

scatter rejection.

 Tests at pulsed and continuous beamlines at:

  • ORNL SNS and HFIR(SNAP, CG-1)
  • PSI (Neutra, FunSpin)
  • ISIS (ROTAX)
  • FRM-11 (Antares)

( )

NOVA Scientific, Inc. 8

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Tests with PSI Imaging Resolution Target

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Image Improvement Occurs Even at Close Positioning

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Even More Advantageous as Sample Is Placed Further from Detector

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Considerable Image Improvement Observed

NOVA Scientific, Inc. 12

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NOVA MCP N t D t t NOVA MCP Neutron Detectors

(used in conjunction with the MCP-based collimator tests)

Real-time neutron imaging and TOF: ea t e eut o ag g a d O ~10 µm imaging resolution) 1 µs timing resolution ~1 µs timing resolution

NOVA Scientific, Inc. 13

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Neutron-Sensitive MCP as Detector

 10B (or Gd) incorporated into base glass

material material

Reactants create secondary electrons - reactant ranges well-matched to channel wall thickness

Neutron

Secondary e-’s amplified to large ~1ns output pulses

Spatial resolution set by pore size (5-10 µm)

7Li

 e- e- e- e- e-

Spatial resolution set by pore size (5 10 µm)

Timing resolution set by 1mm MCP thickness (~1 µs)

Neutron efficiency ~ 3He

10B

Secondary Electrons

e e

coating to release e-

Neutron efficiency ~ 3He

Neutron sensitivity/cm2 > 3He (1.6-1.7x)

release e

NOVA Scientific, Inc. 14

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MCP Neutron Detector with Medipix/Timepix Readout

(a separate DOE Phase II STTR with UCal-Berkeley) (a separate DOE Phase II STTR with UCal Berkeley)

  • Double MCP stack is placed ~0.5 mm above

Medipix2/TimePix readout.

  • Front MCP provides neutron conversion, rear MCP ‘amplifier’

further boosts output pulse to > 106 e- for pulse counting further boosts output pulse to > 10 e for pulse counting.

NOVA Scientific, Inc. 15

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Imaging Examples of MCP Detector with Medipix

Fuel injection nozzle Dual energy image acquisition In collaboration with M. Muehlbauer, B. Schillinger, January 2009, FRM2, ANTARES beamline

1.7 mm 1.7 mm

14 mm 14 mm

PSI Gd resolution mask 11 m MCP pores are seen 11 m MCP pores are seen Presently very low counting rate NOVA Scientific, Inc. 16

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Tomographic Reconstruction

MCP Neutron Imager 1 µs timing resolution MCP Neutron Imager, 1 µs timing resolution (5 meV cold neutrons at ICON beamline, PSI)

NOVA Scientific, Inc. 17

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Tomography Animations Using MCP/Medipix Neutron Detector

Reconstructions and visualizations by M. Muehlbauer (TUM) and Anders Kaestner (PSI)

NOVA Scientific, Inc. 18

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Summary

 MCP-based neutron collimators can effectively reduce

the divergence of lower L/D neutron beamlines

 MCP collimators can effectively reduce scattering

between the target and detector, leading to improved t t d fi iti d l ti contrast, definition, and resolution

 Nova Scientific’s neutron-sensitive MCP and neutron

collimator together with the Medipix Collaborations’s collimator, together with the Medipix Collaborations’s readout, offers an extremely powerful high spatial and timing resolution neutron detection system (~10 µm and ~1 µs).

 Nova Scientific and UCal-Berkeley appreciate the

support of the DOE SBIR-STTR program!

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