Methods and systems for evaluating a target using pulsed, energetic particle beams
Inventors
Hunt, Sean Matthew • Johnson, Joseph Allen
Assignees
Publication Number
US-11726069-B2
Publication Date
2023-08-15
Expiration Date
2041-07-08
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Abstract
A method for evaluating a target, the target having a surface, includes pulsing a defined, energetic particle beam through the surface and into the target such that particle energy deposition from the particle beam is concentrated in a subsurface target volume within a target medium of the target. The deposited particle energy induces a thermoelastic expansion of the target medium in the target volume that generates a corresponding acoustic wave. The method further includes detecting the acoustic wave from the target medium.
Core Innovation
The invention discloses methods and systems for evaluating a target by pulsing a defined, energetic particle beam—such as an electron beam, proton beam, or X-ray beam—through the surface and into the target so that particle energy deposition from the beam is concentrated in a subsurface target volume within a target medium. This concentrated deposition induces a thermoelastic expansion in the target medium, generating a corresponding acoustic wave, which is then detected. The energy deposition is achieved either by focusing the particle beam using a lens system with a focal point in the target medium or by using techniques such as Bragg peak calibration for protons or multiple converging X-ray beams.
The problem addressed is the need for nondestructive evaluation (NDE) of unique structures and composite materials, particularly those that are fragile, sensitive to contamination, or easily damaged by contact. Existing NDE methods, such as laser-induced ultrasound and various electromagnetic techniques, are often limited by shallow penetration depth, shadowing from layered defects, material properties, or component geometry. There is a demand for non-contact approaches that can provide valuable NDE data without being hindered by these limitations.
The method detects the induced acoustic wave from the target medium, using contact or non-contact acoustic sensors (including transducers or laser vibrometers) that convert the acoustic wave into electrical signals for further processing to characterize the target. These methods enable detection of discontinuities, defects, voids, or variations in material or layer bonding, and can be implemented for scanning and mapping across different target volumes. The system supports evaluation through intervening objects or gaps and is adaptable for various particle beams to suit specific evaluation needs.
Claims Coverage
There are three independent claims, covering methods and systems for evaluating a target using pulsed and focused energetic particle beams, and specifically a method using a collimated proton beam with Bragg peak targeting.
Pulsing a focused energetic particle beam into a subsurface volume
A method that comprises pulsing a defined, energetic particle beam—selected from an electron beam, a proton beam, or an X-ray beam—through a surface and into the target such that the particle energy deposition is concentrated in a subsurface target volume within the target medium at a focal point located at a positive, nonzero depth. The concentration of particle energy deposition induces a thermoelastic expansion that generates a corresponding acoustic wave, which is subsequently detected from the target medium.
System for evaluating a target using a focused particle beam and acoustic detection
A system comprising an energetic particle beam generator configured to pulse a defined, energetic particle beam—being an electron beam, a proton beam, or an X-ray beam—through the surface and into the target. The system is configured to focus the particle beam at a focal point of positive, nonzero depth to concentrate energy deposition, thus inducing a thermoelastic expansion that generates an acoustic wave. An ultrasonic sensor is included for detecting the acoustic wave from the target medium.
Collimated proton beam method with Bragg peak targeting
A method involving pulsing a defined collimated proton beam through the surface and into the target, in which the energy of the proton beam is selected such that a Bragg peak of the beam is located at a selected positive, nonzero depth within the target medium, thereby concentrating the particle energy deposition within the subsurface target volume for thermoelastic acoustic wave generation and detection.
The inventive features focus on specific methods and systems for nondestructive evaluation using pulsed, focused energetic particle beams to induce and detect subsurface thermoelastic acoustic waves, with claims covering different beam types and focusing or energy selection strategies.
Stated Advantages
The PRIA method enables detection of defects that are impossible to find with traditional ultrasonic methods.
Surface condition of the target does not impede energy absorption; reflective or clear materials can be evaluated equally by the method.
The technique allows for completely non-contact evaluation, reducing the risk of contamination or damage.
Evaluation is not hindered by air gaps, delamination, or material boundaries within the target.
Particle beams can be focused or steered to concentrate energy deposition at a chosen subsurface volume, improving spatial resolution.
The method is compatible with existing non-contact acoustic sensing technologies, such as laser interferometry or vibrometers.
Documented Applications
Nondestructive evaluation of materials and structures, including unique structures and composite materials.
Characterization of defects, voids, material variations, inclusions, or different material layers within a target.
Characterization of the magnitude or size of a defect in the target.
Characterization of bonding between multiple layers in the target, including layers of same or different materials or orientations.
Inspection of multi-wall vessels and structures with features that may impede ultrasonic waves, such as double-walled or obstructed targets.
Hybridization with pre-installed thin-film piezoelectric sensors or future non-contact technologies for ultrasonic wave detection in structures with air gaps.
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