Pie-Shaped Boron-Coated Straws for Higher Neutron Sensitivity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional boron-coated straw neutron detectors have limitations in sensitivity and efficiency due to their round cross-sectional design, which affects the coated area and electric field uniformity, leading to suboptimal neutron detection performance.

Innovation Solution

The design is modified to a pie-shaped cross-section with radially oriented septa, increasing the coated area and maintaining electric field uniformity, enhancing sensitivity and detection efficiency by tripling the coated wall area compared to a round straw of the same diameter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a round cross-sectional design is used, then the manufacturing process is simple, but the coated area and detection sensitivity are limited

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddetection sensitivity
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies asymmetry by transitioning from a symmetric round cross-section to an asymmetric pie-shaped cross-section with radial septa. This asymmetric geometry increases the coated surface area by creating multiple triangular segments that radiate from the center, thereby enhancing neutron detection sensitivity while maintaining manufacturing feasibility through standardized forming processes.

Inventive Principle:
Principle #4Asymmetry

2Measurement precision

If the coated area is increased to improve sensitivity, then detection efficiency improves, but the device complexity increases

Engineering Contradiction:
Improvedetection sensitivityVSAvoidstructural complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the straw detector into multiple radial segments or septa that extend from the outer wall toward the center. Each segment is coated with boron-10 enriched material, and the segmented structure increases the total coated surface area. The segments are arranged radially to maintain electric field uniformity while enhancing neutron detection capability through increased coated area.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If radial septa are added to increase coated area, then sensitivity improves, but electric field uniformity may be disrupted

Engineering Contradiction:
Improvedetection sensitivityVSAvoidelectric field uniformity
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by carefully designing the septa structure to have different properties in different regions. The septa are positioned and dimensioned to locally increase coated area in regions that maximize neutron detection while minimizing disruption to the overall electric field distribution. The radial orientation and spacing of septa are optimized to maintain field uniformity in the active detection regions.

Inventive Principle:
Principle #3Local quality

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 pie-shaped design significantly improves neutron detection sensitivity, achieving comparable sensitivity to traditional 3He detectors at smaller diameters and demonstrating higher count rates and resolution in laboratory tests, with prototypes showing 95% of theoretically predicted gains.

Implementation Method 1

boron-coated straw detector technology... boron-coated metal (preferably copper) tubes... thin layer of 10B enriched boron coating

Methodology Applied
Scientific EffectNeutron absorption: Absorption (physical)

Implementation Method 2

operated as a proportional counter, with its wall acting as the cathode, and a thin wire tensioned through its center serving as the anode electrode, operated at a high positive potential

Methodology Applied
Scientific EffectElectric field: Electric Field

Data Source

PatentEP3529638B1Boron coated straws for neutron detection with pie-shaped cross-section
Publication Date: 2024.02.21 PROPORTIONAL TECHNOLOGIES INC
  • EP3529638B1 patent drawingFigure 1~2
  • EP3529638B1 patent drawingFigure 3~4
  • EP3529638B1 patent drawingFigure 5~6

AI summary

A boron coated straw detector for use in a neutron detection system is disclosed comprising a boron coated straw having at least one boron-coated septum radially oriented and extending a pre-determined distance towards the center of the straw. Preferably, the straw comprises a plurality of septa comprising a rigid surface, coated on both sides with a boron composition. Preferably, the septa run the length of the straw detector from one end of the straw to the other. The area coated on the septa adds to the area coated on the arc segments offering a significant benefit in sensitivity of the neutron detector.