Insertable Cathode Ion Source for Stable Beam Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The ion source in existing synchrocyclotrons experiences beam divergence and decreased beam current due to electric field disturbances caused by the separation of the plasma column, necessitating time-consuming position adjustments during cathode replacement, which lowers device operation rates.
Innovation Solution
An ion source design featuring a chimney fixed to the acceleration cavity with insertable cathodes, allowing for independent cathode replacement without affecting the position of the chimney or radio frequency electrode, thereby simplifying maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the housing is interrupted to expose the plasma column for particle acceleration, then the acceleration function is achieved, but the extracted ion beam diverges and beam current decreases due to electric field disturbance
Solution Approach 1:
The patent introduces a cathode support structure as an intermediary component between the cathode and the housing. This support structure includes positioning features that maintain precise spatial relationships, acting as a mediator that ensures the plasma column remains properly positioned relative to the acceleration cavity while allowing cathode replacement without compromising beam quality or current
2Ease of repair
If the cathode is replaced in the existing structure, then the damaged cathode can be replaced, but position adjustment is required every time which takes time and lowers device operation rate
Solution Approach 1:
The patent implements preliminary positioning actions by incorporating fixed positioning features (such as positioning holes and positioning protrusions) into the cathode support structure and housing before cathode replacement occurs. This preliminary setup ensures that when the cathode is replaced, it automatically assumes the correct position without requiring time-consuming adjustment procedures
Solution Approach 2:
The cathode support structure is designed to automatically self-position the cathode through integrated positioning mechanisms. The support structure includes features that guide and secure the cathode in the correct position during replacement, enabling the system to service itself without requiring external alignment tools or procedures
3Ease of repair
If the plasma column is separated to allow cathode access, then the cathode can be replaced, but the beam extraction electric field is disturbed due to the column space generated by separation
Solution Approach 1:
The patent employs a nested structure where the cathode is inserted into the cathode support structure, which in turn is positioned within the housing. This nested arrangement allows the cathode to be accessed and replaced through the support structure without requiring separation that would create column space and disturb the electric field, maintaining precise positioning throughout the replacement process
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
Enhances maintainability by facilitating quick cathode replacement and reducing the need for repositioning, improving device operation rates and beam current efficiency.
Implementation Method 1
a voltage source that applies a radio frequency (RF) voltage to the cavity to accelerate particles from the plasma column in an acceleration region
Implementation Method 2
a magnetic structure that applies a magnetic field to a cavity
Data Source
Figure 1
Figure 2
Figure 3
AI summary
To enhance maintainability. An ion source 3 that extracts an extraction beam 15 from an acceleration cavity A in a magnetic pole 1 includes a chimney 22, at least one cathode 23, a radio frequency acceleration electrode 8, and a dummy electrode 9. The chimney is fixed to the acceleration cavity. The at least one cathode is insertably disposed within the chimney. The cathode is a pair of cathodes that are inserted from both sides of the chimney and arranged to face each other. The radio frequency acceleration electrode accelerates the extraction beam. The dummy electrode is disposed opposite to or in parallel with the high frequency acceleration wave electrode. The chimney is electrically connected to the dummy electrode via a contact C.