Flexible Sheet Electrode for MCP Ion Feedback Suppression

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional charged particle detectors face challenges in achieving high-sensitivity ion detection in low-vacuum environments due to increased dark noise from residual gas ionization, particularly due to ion feedback from unnecessary positive ions generated between electrodes, which complicates the detection of charged particles.

Innovation Solution

A charged particle detector incorporating an MCP assembly with a flexible sheet electrode having a mesh area and a deformation suppressing portion, allowing for a higher opening ratio while maintaining physical strength, effectively traps unnecessary charged particles and suppresses ion feedback by arranging the flexible sheet electrode as both an accelerating and trapping electrode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a mesh electrode with high opening ratio is used to improve electron transmittance, then the physical strength of the electrode decreases making it difficult to handle

Engineering Contradiction:

Improveelectron transmittanceVSAvoidphysical strength of mesh electrode

Core Design Contradiction:

Illumination intensityVSStrength

Solution Approach 1:

The patent applies a flexible sheet electrode with mesh structure that can be bent and deformed without breaking. This flexible electrode maintains high opening ratio for electron transmittance while the material flexibility provides sufficient mechanical strength for handling and installation, resolving the contradiction between transmittance and strength.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent uses a composite structure combining mesh area with high opening ratio and deformation suppressing portions with higher strength. This composite design allows different regions to serve different functions: the mesh area maximizes electron transmittance while the deformation suppressing portions provide mechanical strength and stability during handling.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If conventional rigid mesh electrodes are used, then handling and installation are difficult, but if flexible electrodes are used, then maintaining physical strength becomes challenging

Engineering Contradiction:

Improvehandling and installationVSAvoidphysical strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The patent employs a flexible sheet electrode that can be easily bent, folded, and installed in various configurations. The flexibility of the material itself provides the ease of operation needed for handling and installation, while the mesh structure and deformation suppressing portions maintain sufficient physical strength.

Inventive Principle:

Principle #30Flexible shells and thin films

3Speed

If accelerating electrode potential is increased to improve electron acceleration, then unnecessary positive ions are also accelerated toward the MCP unit causing ion feedback

Engineering Contradiction:

Improveelectron acceleration speedVSAvoidion feedback

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent divides the electrode system into separate accelerating electrode and trapping electrode components with different potentials. The accelerating electrode can be optimized for electron acceleration while the trapping electrode independently suppresses ion feedback by maintaining a potential that prevents positive ions from reaching the MCP unit, thus resolving the contradiction between acceleration speed and ion feedback suppression.

Inventive Principle:

Principle #1Segmentation

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 flexible sheet electrode design enhances handling and installation, allowing for improved transmittance of secondary electrons and effective trapping of unnecessary ions, thereby reducing dark noise and enhancing sensitivity in low-vacuum conditions.

Implementation Method 1

a charged particle detector provided with a multiplying means such as the MCP for obtaining a constant gain

Methodology Applied

Scientific EffectSecondary electron emission: Photoelectric Effect

Implementation Method 2

voltages of different values (negative voltages) are applied from a voltage control circuit (bleeder circuit) so that potential of the output surface 200b is higher than that of the input surface 200a

Methodology Applied

Scientific EffectElectric field acceleration: Electric Field

Implementation Method 3

effective trapping of unnecessary ions, thereby reducing dark noise

Methodology Applied

Scientific EffectIon trapping: Ion Repulsion/Attraction

Data Source

PatentUS11315772B2MCP assembly and charged particle detector

Publication Date: 2022.04.26 HAMAMATSU PHOTONICS KK

AI summary

An MCP assembly of this embodiment is provided with an MCP unit and a flexible sheet electrode having a structure for facilitating handling thereof as a single body. The flexible sheet electrode is constituted by a mesh area provided with plural openings and a deformation suppressing portion surrounding the mesh area. Both the mesh area and the deformation suppressing portion are comprised of the same conductive material, and physical strength of the deformation suppressing portion is higher than that of the mesh area. With this configuration, the physical strength of an entire flexible sheet electrode is secured even if an opening ratio of the mesh area is increased, so that the handling of the flexible sheet electrode as a single body is facilitated.