Innovation in Sensing

Bill Priedhorsky13 September 2010

Landscape for innovation (partial)• Nano-enabled scintillators and detectors• Gamma-ray imaging (Compton)• High resolution superconducting detectors• Laser-driven sources for active interrogation• Nuclear resonance imaging• Integrating multiple radiographies• Neutrino detection• Muon radiography and muonic x-rays• THz sources and detectors• Quantum detectors: B, gravity, gradiometry• Smart, mobile detectors to overcome R2

• Stable isotopics at a particular molecular site• Grain-level chemical history• Biochemical perturbations in plants and animalsIdeas from LDRD and elsewhere

Example:Detection of nuclear radiations sounds easy…

Gammas or neutronsfrom a nuclear threat

…but backgrounds can be crippling

Same source in the presence of

background

Can anything be done?

Yes!

1. Get more signal with a bigger detector

Same source, same

background, 30 times larger

detector

Very large detectors

2. Reduce the background

Same source, 10 x less

background (imaging or

spectroscopic detector)

Quantum-dot activated scintillator and semiconductor

detectors

3. Make the source brighter

Source 10x brighter

Active interrogation

Event

Bring sensor closer – distributed sensor nets

4. Look at its shadow (radiography)

Radiographicimage

Muon radiograph (C-clamp)

Analyzing possibilities for improvement

Smin = min 4 π r2 E1/2 √(B + I) A-1/2 T-1/2 (fov/scan)-1/2 -1

or if B >> I

Smin = min 4 π r2 E1/2 B1/2 Aeff-1/2 T-1/2 (fov/scan)-1/2

Smin Source emission h s-1 into 4 min Minimum acceptable signal-to-noiser Source range cmE Detector energy resolution keVDetector angular resolution radians (pixel solid angle = 2)B Diffuse background h cm-2 s-1 keV-1 sr-1

Detector efficiencyI Intrinsic detector background counts cm-2 s-1 keV-1 sr-1

A Detector area cm2

Aeff Detector effective area cm2

T Total observation time sfov Solid angle viewed at any instant srscan

Total solid angle to be monitored sr

Detection of narrow-line point

source

Points of leverage

Smin = min 4 π r2 E1/2 B1/2 Aeff-1/2 T-1/2 (fov/scan)-1/2

Spectral resolutionUntangle complex spectra

ProximityAngular resolutionUntangle confused regions, map

AreaBrute force not much help

Instantaneous f.o.v.Capture fast events

Not captured in equationHigh time resolutionTypically photon-limitedFast response multi-spectralTransient multi-physics

Landscape for innovation (repris)• Nano-enabled scintillators and detectors• Gamma-ray imaging (Compton)• High resolution superconducting detectors• Laser-driven sources for active interrogation• Nuclear resonance imaging• Integrating multiple radiographies• Neutrino detection• Muon radiography and muonic x-rays• THz sources and detectors• Quantum detectors: B, gravity, gradiometry• Smart, mobile detectors to overcome R2

• Stable isotopics at a particular molecular site• Grain-level chemical history• Biochemical perturbations in plants and animalsIdeas from LDRD and elsewhere

Cryogenic Microcalorimeters:First measurement of 235U and 226Ra splitting

Courtesy Mike Rabin

Laser acceleration approaches 1 GeV/AMU

Courtesy Mike Rabin

courtesy K. Flippo

Mobility allows smart search & detection

Simulated model-driven search. Belief in source location evolves with time, quickly converging on the correct (leftmost) bin

A. Klimenko, W. Priedhorsky, N. Hengartner, and K. Borozdin, “Efficient Strategies for Low Statistics Nuclear Searches”, IEEE Trans. Nucl. Sci., (2006)

time

source bin background bins

Simulated smart search performance

A. Klimenko, W. Priedhorsky, N. Hengartner, and K. Borozdin, “Efficient Strategies for Low Statistics Nuclear Searches”, IEEE Trans. Nucl. Sci. (2006)

Smart search

Not-so-smart search

Distributed sensors face reality

• Fundamental issues– Power– Communications– Placement and

localization– Reliability– Sensor miniaturization

– Security• Watch for commercial

developments!

Vision: ask questions of a model, not a measurement

Model

Measurement

World

Measurements drive the model

The needs of the model drive measurement

Users should interactwith the model

Not with the measurements

Collaborate across disciplines – but thoughtfully

Wolfgang PauliNobel Physics 1945

Physics: Postulates neutrino Chemistry:

Exclusion principle essential to electron orbitals

She runs off with a chemist 1930

Marries Berlin dancer Käthe Deppner 1929

Backup slides

Detection faces problems of scale

Cuba 1962: 0.1 km2 missile field in a 100,000 km2 countryTerrorism today: 1 m2 target in a 1,000,000 km2 region

Cuba 1962

Afghanistan/Pakistan today