Helical Spin-Roll Beam Chopper for X-Ray Scanning

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Solution Overview

Problem

Current X-ray screening systems for detecting concealed threats are limited by their inability to accurately distinguish low-Z materials from the human body, resulting in poor image quality and high radiation exposure, and are hindered by the weight and balance issues of conventional beam chopping mechanisms, which restrict portability and efficiency.

Innovation Solution

A spin-roll beam chopper apparatus with helical apertures that allows for variable velocity and beam spot size, enabling a lightweight and balanced system capable of producing a vertically moving beam spot with constant velocity for improved image clarity and threat detection across varying distances without excessive radiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional beam chopping mechanisms are used, then radiation exposure is limited, but system weight increases and portability decreases

Engineering Contradiction:
Improveradiation exposureVSAvoidsystem weight
Core Design Contradiction:
Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The patent replaces the conventional disc wheel chopper with a cylindrical chopper that rotates about its central axis. This cylindrical configuration allows the beam to be chopped by the rotation of the cylinder, eliminating the need for large radial extensions and reducing the overall moment of inertia and weight of the chopper assembly while maintaining effective beam control and radiation limitation

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention transitions from a two-dimensional disc wheel configuration to a three-dimensional cylindrical configuration. By utilizing the cylindrical geometry and rotating the chopper about its central axis, the system achieves beam chopping functionality in a new spatial dimension, reducing the radial footprint and allowing for a more compact, lightweight design that maintains radiation safety

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Object-affected harmful factors

If conventional beam chopping mechanisms are used, then radiation exposure is controlled, but balance and gyroscopic effects increase

Engineering Contradiction:
Improveradiation exposureVSAvoidbalance stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The cylindrical chopper configuration with central axis rotation eliminates the gyroscopic effects inherent in disc wheel designs. The symmetric cylindrical geometry rotating about its centroidal axis creates balanced mass distribution, preventing wobble and vibration that occur in disc wheel systems, especially at varying RPMs

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The cylindrical design inherently provides balanced weight distribution around the rotation axis, counteracting any potential imbalance forces. The uniform cylindrical geometry ensures that mass is evenly distributed, eliminating the need for complex counterweight mechanisms required in disc wheel systems

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Object-affected harmful factors

If radiation dose is reduced for safety, then image quality deteriorates, but radiation exposure decreases

Engineering Contradiction:
Improveradiation exposureVSAvoidimage quality
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent replaces mechanical methods of increasing radiation dose with a focused, scanning beam approach. By concentrating the X-ray energy into a narrow beam that scans across the subject, the system achieves high image quality with low total radiation exposure, as only the immediate beam path receives high intensity at any given moment

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The scanning beam operates through periodic scanning motion, concentrating radiation intensity at each scan point while moving continuously across the subject. This periodic concentration and movement allows sufficient image detail to be captured at each location without requiring high overall radiation exposure across the entire subject

Inventive Principle:
Principle #19Periodic action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The spin-roll chopper system enhances threat detection performance and image clarity while reducing radiation exposure, allowing for efficient scanning at various distances and improving portability by maintaining a lightweight design.

Implementation Method 1

A spin-roll beam chopper apparatus with helical apertures that allows for variable velocity and beam spot size, enabling a lightweight and balanced system capable of producing a vertically moving beam spot with constant velocity

Methodology Applied
Scientific EffectX-ray beam modulation:

Implementation Method 2

images of various types of material can be generated using X-ray scattering. The intensity of scattered X-rays is related to the atomic number (Z) of the material scattering the X-rays

Methodology Applied
Scientific EffectX-ray scattering: Scattering

Implementation Method 3

X-ray absorption and scattering further reduces the amount of X-rays available to form an image of the person and any concealed objects

Methodology Applied
Scientific EffectX-ray absorption: Absorption (EM radiation)

Data Source

PatentEP2548207B1Beam forming apparatus
Publication Date: 2020.02.12 RAPISCAN SYST INC (US)
  • EP2548207B1 patent drawingFigure 1
  • EP2548207B1 patent drawingFigure 2
  • EP2548207B1 patent drawingFigure 3A

AI summary

The present specification discloses a beam chopping apparatus, and more specifically, a helical shutter for an electron beam system that is employed in radiation-based scanning systems, and more specifically, a beam chopping apparatus that allows for variability in both velocity and beam spot size by modifying the physical characteristics or geometry of the beam chopper apparatus. The present specification also discloses a beam chopping apparatus which provides a vertically moving beam spot with substantially constant size and velocity to allow for substantially equal illumination of the target. In addition, the present specification is a beam chopping apparatus that is lightweight and does not cause an X-ray source assembly employing the beam chopper to become heavy and difficult to deploy.