A C OMPLETE M ICRO/ N ANO S YSTEM S OLUTION FOR A LPHA, B ETA, G AMMA, AND N EUTRON D ETECTION Dr. Chester Wilson Louisiana Tech University President, Cybercorps Interactive

Why Is Nuclear Energy a Big Part of The Answer? Decades of operational safety exceeding other energy producers. Zero greenhouse gas emissions. Fantastic power densities. Domestic energy production.

Why Is Nuclear Energy a Big Part of The Answer? Decades of operational safety exceeding other energy producers. Zero greenhouse gas emissions. Fantastic power densities. Domestic energy production. Around 40% of plant fuel comes from reprocessed ex-soviet nuclear weapons.

Weapons Grade Plutonium Becoming Energy

Other Guys Want it Too

Traditional Radiation Detectors Traditional Method of Detection is Geiger Counter. Problem: Most detect Alphas, Betas, Gammas, but not Neutrons. He 3 and BF 3 tubes detect neutrons, but are toxic and expensive.

Traditional Radiation Detectors Traditional Method of Detection is Geiger Counter. Problem: Most detect Alphas, Betas, Gammas, but not Neutrons. He 3 and BF 3 tubes detect neutrons, but are toxic and expensive. Important because weapons grade plutonium emits neutrons, not much else does

How do you shield neutrons? Bomb Maker Terrorist Lead ?

N eutrons vs. Lead Neutron interacting with Pb Since the mass of the neutron is much smaller than the larger Pb atoms, the neutron recoils without losing much energy. The neutrons continuously bounce around able to exit the lead shielding.

N EED FOR D ETECTORS Bomb Maker Terrorist Plastic ?

N EED FOR D ETECTORS Neutron interacting with H Since the mass of the neutron is approximately equal to the H atoms, the neutron can transfer up to its full energy. The recoil H nuclei has a small range losing energy quickly.

Transparency! This scintillator is loaded with 30% gadolinium oxide, but because the nanoparticles are too small to scatter light, it is transparent. Gadolinium oxide is opaque, but… Nanoparticle Neutron Detection And this allows a patternable film to make imaging Arrays with better spatial resolution and gamma selectivity.

Nanoparticle Neutron Detection Neutron detection is enabled through gadolinium nanoparticles, 255,000 barn absorption: 1000X smaller than anything else. Measurements taken at Entergy Nuclear’s Grand Gulf Facility

Problem: limited to the types of radiation detected Solution: dope with charge conversion nanoparticles Radiation impinging on tailored nanoparticles create electrons, which scintillates a background matrix. WO 3 – Beta DetectionPb 3 O 4 – Gamma/X-ray Detection Glass – Alpha DetectionGd 2 O 3 – Neutron Detection Four Channel Device

Four channels embedded into a sandblasted glass substrate Optical cross talk barrier to reduce cross talk between detector channels D EVICE D ESIGN

R ESULTS Gamma detection— 60 Co emits both gammas and betas so lead sheets are used to block betas in order to detect only gammas and demonstrate the difficulty in shielding gammas. Pulse height spectroscopy— Tailored resins use different conversion mechanisms producing varying PM tube outputs

Varying thicknesses for top layer scintillator allows for different count rates Energy spectroscopy capability by determining where the energy deposition took place as a function of top layer thickness M ULTIPLE L AYERS M ORE I NFORMATION

Top layer— With a decay constant of 2.3 ns, the created photons produce a ringing pulse. R ESULTS Bottom layer— With a decay constant of 285 ns, the created photons do not produce a ringing pulse.

Power Converter P RINTED C IRCUIT B OARD High Voltage Pulse Shaping

Design the printed circuit board using Eagle software. P RINTED C IRCUIT B OARD Autoroute function to layout the copper traces after the components are placed.

Photocathode Series of Dynodes Anode Microscale Photomultiplier Tube Photomultiplier tube components

Beating the State of the Art The count rates increase from non-doped scintillator to heavier doped scintillator. Neutron sensitivity around 11% vs. around 0.2% on tube

Fully integrated radiation detector Build smaller and cheaper components Integrated Circuits Miniaturized PM tube Goal Hockey puck style detector Pager sized Eventually pen sized Working Towards Cheap Pen Size Detector

Thanks Funding Sources: Entergy Nuclear Department of Energy National Science Foundation Office of the Director of National Intelligence