Charged Particle Beam Power Circuit for Low-Noise Measurement
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Solution Overview
Problem
Charged particle beam apparatuses face noise issues due to AC-DC power supply switching noise, which is difficult to remove, especially in high impedance circuits, and existing solutions like dropper power supplies have low power conversion efficiency and fluctuating DC voltages, while battery-powered systems require frequent replacement and limited installation locations.
Innovation Solution
A charged particle beam apparatus with a power storage device that stores DC voltage and is charged during non-measurement periods, using a control circuit to manage charging and prevent noise during measurement periods, thereby reducing power supply noise and simplifying battery replacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a switching power supply is used to convert AC voltage to DC voltage, then power conversion efficiency is improved and miniaturization is achieved, but switching noise is transmitted to various circuits via power supply wiring
Solution Approach 1:
The power supply system is segmented into two independent parts: a switching power supply for efficient power conversion and a linear power supply for noise-sensitive circuits. This segmentation isolates the noise source from the sensitive circuits while maintaining high efficiency in the power conversion path.
Solution Approach 2:
A linear power supply acts as an intermediary between the AC power source and the noise-sensitive detection circuits. It provides a clean, low-noise DC voltage to the detection circuits while the switching power supply handles the main power conversion tasks.
2Object-affected harmful factors
If a dropper power supply using a transformer is used instead of a switching power supply, then switching noise is avoided, but power conversion efficiency is reduced and DC voltage fluctuates due to temperature drift
Solution Approach 1:
The power supply functions are segmented between switching and linear power supplies. The switching power supply handles efficient power conversion while the linear power supply provides stable, low-noise output, combining the advantages of both approaches.
Solution Approach 2:
The invention merges switching power supply efficiency with linear power supply stability by using both types in the same system. The switching power supply converts AC to DC efficiently, while the linear power supply regulates the voltage with minimal noise and temperature drift.
3Object-affected harmful factors
If a battery is used as a power storage device, then noise is isolated from the measurement circuits, but time and effort are required to replace the battery and installation location is limited
Solution Approach 1:
The power storage device is designed to be rechargeable and integrated into the measurement probe, allowing it to serve itself by being recharged during instrument operation or between uses, eliminating the need for manual replacement and reducing maintenance time.
Solution Approach 2:
The rechargeable power storage device serves multiple functions: providing isolated power to noise-sensitive circuits, enabling portable operation, and being rechargeable rather than disposable. This multi-functionality replaces the battery with a more versatile power solution.
4Duration of action of stationary object
If a power storage device is charged during measurement periods, then continuous power is available, but noise from charging interferes with measurement accuracy
Solution Approach 1:
The charging operation is performed periodically during non-measurement intervals rather than continuously during measurements. This periodic charging ensures continuous power availability from the power storage device during measurements while avoiding charging noise interference with measurement accuracy.
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 solution effectively suppresses power supply noise, reduces the effort and time required for battery replacement, and improves noise isolation, enhancing measurement accuracy and efficiency while allowing for miniaturization and flexible installation.
Implementation Method 1
a charge circuit including a power storage device configured to store a DC voltage
Data Source
AI summary
A charged particle beam device according to the present invention comprises a charged particle source that emits charged particles, a detection circuit that detects electrons which are generated by a sample as a result of irradiation with the charged particles, and a power storage device (107_VHD) that holds direct voltage, and comprises a charge circuit (107_CHG) that charges the power storage device with supplied voltage, and a control circuit (107_CTL) that controls the charge circuit such that charging is carried out in a period in which no sample is measured, wherein the direct voltage held by the power storage device (107_VHD) is used as operating voltage.