Neutron Source Pulsed Plasma Target Cooling
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Solution Overview
Problem
Conventional neutron generating sources face challenges in producing high neutron flux due to excessive target heating and magnetic field interference, leading to reduced ion flux and target life, necessitating continuous target replacement.
Innovation Solution
A neutron or gamma ray generating source is designed with a magnetic field and plasma chamber to generate high-density plasma and control target voltage in various modes, preventing excessive heating and allowing continuous operation by adsorbing nuclear fusion reactant elements on the target, enabling high ion flux and extended target life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If RF ICP plasma is used to generate high ion flux for neutron production, then neutron flux is improved, but target surface temperature increases excessively causing evaporation of reactant elements
Solution Approach 1:
The patent applies periodic action by operating the plasma source in pulsed mode rather than continuous mode. The plasma is generated only during specific time intervals when neutron production is required, allowing the target to cool down between pulses. This prevents excessive cumulative heating and evaporation of reactant elements while still achieving high neutron flux during the active plasma periods.
Solution Approach 2:
The patent applies preliminary action by pre-cooling the target or preparing the plasma source in advance before each pulse. The system is configured to maintain the target at an optimal temperature state before plasma irradiation begins, preventing thermal runaway and ensuring sustained operation without excessive heating.
2Quantity of substance
If magnetic field is generated near the target to confine plasma, then plasma density is improved, but ion flux to target decreases due to magnetic field blocking
Solution Approach 1:
The patent applies local quality by creating different magnetic field strengths in different regions. Strong magnetic fields are applied in the bulk plasma region to confine and densify the plasma, while the magnetic field strength is reduced or eliminated in the immediate vicinity of the target surface. This allows plasma to be dense overall while still permitting ion flux to reach the target effectively.
Solution Approach 2:
The patent segments the magnetic field application into distinct zones: a strong magnetic confinement zone for plasma density enhancement and a magnetic field-free or weak field zone near the target for ion transport. This spatial segmentation resolves the contradiction by assigning different magnetic field characteristics to different functional requirements.
3Duration of action of moving object
If target is used continuously for neutron generation, then operational duration is improved, but target life decreases due to heating and evaporation
Solution Approach 1:
The patent extends operational duration while preserving target life by using periodic pulsed plasma operation. The target is subjected to plasma irradiation only during short pulses, allowing adequate cooling and recovery time between pulses. This prevents cumulative damage from continuous heating and evaporation, enabling both long operational duration and extended target life.
Solution Approach 2:
The patent achieves continuity of useful action through repeated pulsed cycles. While individual pulses are short, the sequence of pulses maintains continuous neutron production capability over extended periods. The target undergoes repeated cycles of heating during plasma pulses and cooling during off-periods, maintaining operational continuity without compromising target integrity.
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 achieves a high neutron or gamma ray flux with extended target life by minimizing target heating and allowing continuous operation without replacement, facilitating efficient nuclear fusion reactions and target recycling.
Implementation Method 1
a high density of plasma is generated in the vicinity of a target by electron cyclotron resonance
Implementation Method 2
extracting a high ion flux by using plasma sheath produced between the plasma and the target
Implementation Method 3
causing a nuclear fusion reaction expressed as follows: D++D+→n+He3 or D++T+→n+He
Implementation Method 4
generate a magnetic field in the vicinity of a target, generate plasma in a high density inside a space, in which the magnetic field has been generated
Data Source
AI summary
The present invention provides a neutron generating device for generating a high neutron flux by forming plasma in the vicinity of a target and by accelerating electrons and charged particles in the plasma toward the target. Magnetic field is formed in the vicinity of the target and a microwave generator irradiates microwaves into the space where the magnetic field is generated to thereby generate plasma in the space. The accelerated electrons and charged particles collide with the target to generate neutron flux. Also, to prevent the target surface from being excessively heated, the plasma is generated in a pulsed mode and target voltage is applied in a pulsed mode. To secure a continuous process, the level of target bias voltage for the target is adjusted so that the target re-adsorbs elements when the elements adsorbed on the target are depleted.