Back to results
US 8,149,988 B2Granted
Use of nearly monochromatic and tunable photon sources with nuclear resonance fluorescence in non-intrusive inspection of containers for material detection and imaging
AssigneePassport Systems, Inc.
InventorsWilliam Bertozzi, Robert J. Ledoux
Life of this patent
Estimating the term…
Abstract
Methods and systems for detecting potential items of interest in target samples, using nuclear resonance fluorescence, utilize incident photon spectra that are narrower than traditional bremsstrahlung spectra but overlap nuclear resonances in elements of interest for purposes of detection, such as but not limited to the detection of threats in luggage or containers being scanned.
Claims48
A method for detecting a potential item of interest in a target sample, the method comprising:
- a) providing a first source of photons, configured to generate photons by at least one of:
- Compton scattering of photons by electrons;
- passage of a beam of electrons through a periodic lattice;
- and a particle-induced reaction in a nucleus,
- wherein the first source photon frequency is tunable to a plurality of specific energies of interest;
- b) providing at least one photon detector to measure an intensity of photons scattered from at least a portion of the target sample in at least one energy channel;
- c) tuning the first photon source to a first specific energy of interest corresponding to a nuclear resonance in a first nuclear species of interest;
- d) illuminating the target sample with photons from the first photon source having the first specific energy of interest;
- e) upon the intensity of photons detected in at least one of the at least one detector energy channels of interest meeting a predetermined first nuclear species of interest detection criterion, determining that the first nuclear species of interest has been detected;
- f). upon the intensity of photons detected in all energy channels of interest not meeting the predetermined first nuclear species of interest detection criterion, repeating steps d) to e) with the first photon source tuned to a further specific energy of interest corresponding to a nuclear resonance in a further nuclear species of interest.
7 more elements
A method for detecting a potential item of interest in a target sample, the method comprising:
- a) providing a first source of photons, configured to generate photons by at least one of:
- Compton scattering of photons by electrons;
- passage of a beam of electrons through a periodic lattice;
- and a particle-induced reaction in a nucleus,
- wherein the first source photon frequency is tunable to a plurality of specific energies of interest;
- b) providing at least one reference scatterer, the reference scatterer comprising a plurality of nuclear species of interest;
- c) providing at least one photon detector to measure an intensity of photons scattered from the at least one reference scatterer in at least one energy channel;
- d) tuning the first photon source to a first specific energy of interest corresponding to a nuclear resonance in a nuclear species of interest;
- e) illuminating the target sample with photons from the first photon source having the first specific energy of interest;
- f) allowing photons from the first source transmitted through the target sample to scatter from the at least one reference scatterer;
- g) upon the intensity of photons detected in at least one of the at least one detector energy channels of interest meeting a predetermined first nuclear species of interest detection criterion, determining that the first nuclear species of interest has been detected;
- h). upon the intensity of photons detected in all energy channels of interest not meeting the predetermined first nuclear species of interest detection criterion, repeating steps e) to g) with the first photon source tuned to a further specific energy of interest corresponding to a nuclear resonance in a further nuclear species of interest.
9 more elements
Dependencies are inferred from the claim text.