Gas Drift Detector for Large Area X-ray Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing X-ray detectors face a trade-off between achieving low noise performance (energy resolution) and a large active area, with silicon drift detectors offering low noise but small active areas and gas-filled detectors providing large areas but high noise.
Innovation Solution
A gas drift detector design featuring a chamber filled with xenon, krypton, or argon gas, with a small anode and concentric conductive rings, utilizing a low-capacitance amplifier connected via a short bonding wire, and biased by a high negative voltage to achieve low noise and large active area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a silicon drift detector is used, then energy resolution is improved (low noise), but active area becomes small
Solution Approach 1:
The patent uses a gas-filled chamber (pneumatic approach) instead of solid-state silicon drift detector. The gas medium (xenon, krypton, or argon) allows for a much larger active detection area while maintaining low noise performance through electron drift collection, resolving the contradiction between measurement precision and active area.
Solution Approach 2:
The patent changes the state of matter from solid (silicon drift detector) to gas (xenon/krypton/argon mixture). This parameter change enables both large active area and low noise by allowing electrons to drift freely in the gas phase to a small anode, combining the advantages of both detector types.
2Area of stationary object
If a gas-filled proportional counter is used, then active area is improved (large area), but energy resolution deteriorates (high noise)
Solution Approach 1:
The patent extracts the gas amplification region (avalanche region) from the detection volume. Instead of using gas multiplication throughout the chamber, electrons drift through a large volume to a small anode where collection occurs, eliminating the noise from gas amplification variance while preserving large active area.
Solution Approach 2:
The patent introduces an electric field as an intermediary mechanism. The field causes electrons to drift deterministically from the large active area to a small anode, providing a noise-free transport mechanism that bridges the gap between large detection area and precise signal collection.
3Area of stationary object
If a proportional counter with gas amplification is used, then active area is improved, but noise performance deteriorates due to high variance of gas amplification
Solution Approach 1:
The patent converts the harmful effect of gas amplification variance into a benefit by completely avoiding gas amplification. Instead of trying to reduce its variance, the design uses pure electron drift collection in a uniform electric field, where the only signal generation comes from primary ionization, which has very low variance.
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 gas drift detector achieves significantly better energy resolution than gas-filled detectors and larger active areas than silicon drift detectors, enabling fast signal generation and efficient X-ray detection without the need for cooling, suitable for high-count-rate applications and space exploration.
Implementation Method 1
the chamber is filled with a gas... the use of the gas-filled detectors as the X-ray detector... The tube is filled by a gas, such as argon or xenon
Implementation Method 2
the amplifier is electrically connected to the anode... biased by a high negative voltage to achieve low noise... electrons created by an X-ray event drift towards the anode
Implementation Method 3
one or more conductive rings arranged on a surface of the substrate facing inside the chamber, and an amplifier arranged to the opposite surface of the substrate than the conductive rings... The amplifier may be electrically connected to the anode by means of a bonding wire having length less than 10 mm
Data Source
AI summary
The invention relates to a gas drift detector (100) comprising: a chamber formed by: a housing (102) having a first end and a second end; a radiation window (104) arranged to cover an opening of the first end of the housing (102); and a substrate (106) arranged to cover an opening of the second end of the housing (102), an anode (110) arranged to the substrate (106), one or more conductive rings (108) arranged on a surface (106a) of the substrate facing inside the chamber, and an amplifier (112) arranged to the opposite surface (106b) of the substrate than the conductive rings (108). The amplifier (112) is electrically connected to the anode (110). The chamber is filled with a gas.