SiPM Radiation Detection Solid-State Substitution

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional radiation detection systems using PMTs are labor-intensive, expensive, and prone to mechanical shock, magnetic interference, and photocathode degradation, while alternatives often suffer from reduced sensitivity and high thermal drift.

Innovation Solution

The development of a silicon photomultiplier (SiPM)-based radiation detection system that integrates a pixelated silicon wafer with a monolithic silicon design, offering comparable sensitivity to PMTs at reduced costs, immunity to mechanical shock and magnetic interference, and low-voltage operation, with enhanced sensitivity to blue light and improved temperature stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If PMT technology is used for radiation detection, then sensitivity and detection capability are maintained, but manufacturing cost and labor intensity increase significantly

Engineering Contradiction:
Improvedetection sensitivityVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces the vacuum tube PMT structure with a solid-state SiPM structure that copies the functional principles of PMTs. The SiPM uses an array of photodiodes operating in Geiger mode to replicate the photon detection and signal amplification capabilities of PMTs, achieving comparable sensitivity while enabling cost-effective manufacturing through standard semiconductor fabrication processes

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent substitutes the mechanical vacuum tube structure of PMTs with a solid-state semiconductor device. This replacement eliminates fragile glass envelopes, dynode structures, and high-voltage requirements, replacing them with a robust silicon-based structure that can be manufactured using standard semiconductor processes, significantly reducing manufacturing complexity and cost

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

2Measurement precision

If PMT-based systems are used, then radiation detection performance is achieved, but vulnerability to mechanical shock and magnetic interference increases

Engineering Contradiction:
Improvedetection performanceVSAvoidmechanical shock vulnerability
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical vacuum tube structure with a solid-state semiconductor device that has no moving parts or fragile components. The SiPM structure is inherently resistant to mechanical shock and vibration, eliminating the vulnerability of PMT glass envelopes and internal dynode structures while maintaining detection performance

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

Solution Approach 2:

The patent changes the operational parameters from high voltage (1000V or more) required by PMTs to low voltage operation of the SiPM. This parameter change not only reduces power consumption but also eliminates sensitivity to magnetic fields, as the solid-state device operates without the high-voltage electron multiplication processes that are susceptible to magnetic interference

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If alternatives to PMTs are used, then manufacturing cost is reduced, but sensitivity and thermal stability deteriorate

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

Solution Approach 1:

The patent employs temperature compensation techniques and bias voltage adjustment to maintain stable operation of the SiPM across varying temperatures. By dynamically adjusting operational parameters, the system achieves thermal stability comparable to PMTs while maintaining the cost and manufacturing advantages of solid-state devices

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The SiPM structure copies the functional principles of PMTs including photon detection efficiency and signal amplification mechanisms. The array of photodiodes in Geiger mode replicates the single-photon sensitivity of PMTs, achieving comparable detection sensitivity while enabling cost-effective manufacturing

Inventive Principle:
Principle #26Copying

4Measurement precision

If PMT technology is used, then detection capability is maintained, but device size and power consumption increase

Engineering Contradiction:
Improvedetection capabilityVSAvoiddevice size
Core Design Contradiction:
Measurement precisionVSWeight of moving object

Solution Approach 1:

The patent replaces the bulky vacuum tube structure with a compact solid-state semiconductor device. The SiPM integrates photodetection, signal amplification, and output functionality in a small package, eliminating the need for high-voltage power supplies, magnetic shielding, and other auxiliary components required by PMTs, resulting in significant size reduction

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

Solution Approach 2:

The patent integrates multiple functions into the single SiPM device structure. The photodiode array simultaneously performs photon detection, signal amplification through internal gain mechanisms, and provides electrical output, consolidating functions that in PMT systems require separate components including the vacuum tube, high-voltage divider circuitry, and output stages

Inventive Principle:
Principle #5Merging (Combining)

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 SiPM-based system provides a cost-effective, rugged, and sensitive radiation detection solution with reduced size and power requirements, maintaining performance comparable to PMT systems while being more adaptable to harsh environments.

Implementation Method 1

a silicon photomultiplier (SiPM)-based radiation detection system that integrates a pixelated silicon wafer... offering comparable sensitivity to PMTs... with enhanced sensitivity to blue light

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

Scintillation radiation detectors have traditionally used photomultiplier vacuum tube (PMT) technology... SiPM-based radiation detection system

Methodology Applied
Scientific EffectScintillation: Scintillation

Data Source

PatentEP3074790B1Sipm-based radiation detection systems and methods
Publication Date: 2020.10.28 FLIR DETECTION INC
  • EP3074790B1 patent drawingFigure 1A
  • EP3074790B1 patent drawingFigure 1B~1C
  • EP3074790B1 patent drawingFigure 1D

AI summary

Techniques are disclosed for systems and methods using silicon photomultiplier (SiPM) based radiation detectors to detect radiation in an environment. An SiPM-based radiation detection system may include a number of detector assemblies, each including at least one scintillator providing light to a corresponding SiPM in response to ionizing radiation entering the scintillator. The radiation detection system may include a logic device and a number of other electronic modules to facilitate reporting, calibration, and other processes. The logic device may be adapted to process detection signals from the SiPMs to implement different types of radiation detection procedures. The logic device may also be adapted to use a communication module to report detected radiation to an indicator, a display, and/or a user interface.