Analysis And Experimental Research Of ECR Plasma Source

As medical technology continues to advance,proton therapy has emerged as a desirable treatment method.Proton accelerators play a crucial role in the success of proton therapy systems.Currently,there are two main types of proton therapy equipment available: cyclotrons and synchrotrons.Cyclotrons,in particular,can generate a sustained beam,leading to improved treatment outcomes compared to synchrotrons.However,the performance of the ion source within the cyclotron is essential to achieve both the desired beam intensity and accelerator longevity.Moreover,using smaller ion sources can help reduce the size of the accelerator,making it more compact and portable.Therefore,having a small,reliable,and high-intensity ion source is of utmost importance to enhance the overall performance of compact proton therapy equipment.The small-scale ECR ion source,featuring a simple structure and a high proton-toelectron ratio,offers excellent reliability for various applications,especially in smallscale cyclotrons.Compared with the Penning source,it eliminates the need for consumable components like filaments,resulting in a longer lifespan.These distinctive features make the small-scale ECR ion source highly suitable for small-scale cyclotrons.This article provides a brief introduction to the basic parameters and production conditions of ECR plasmas sources,and explains the principle of resonance production.The differences between ECR plasma sources and other plasma sources are also analyzed.The composition of the ECR plasma source experimental platform and the role of its main components are described.In terms of design,finite element analysis was used to analyze and design the microwave input,impedance matching,and magnetic field of the ECR plasma source,in order to meet the design requirements and objectives of the experimental platform.Additionally,the IBSimu software was used to calculate the beam current of the three-electrode extraction system,obtaining results with a relatively concentrated beam and a length of 200 mm.This study systematically investigated the effects of magnetic field structure,gas flow rate,and extraction voltage on the extracted beam of a small ECR plasma source through initial tuning of the designed experimental platform.The results indicate that the magnetic field configuration significantly influences the extracted beam intensity of the small ECR plasma source,and the extracted beam intensity increases linearly with the increase of the extraction voltage and microwave power.Additionally,the extracted beam intensity initially increases and then decreases as the gas flow rate increases.The experimental results also demonstrate that the stability of the extracted beam remains good with increasing time.During the tuning process of the experimental platform,it was found that when the extraction voltage was increased under otherwise unchanged experimental conditions,the gas tube was prone to discharge and the extraction region would experience severe arcing,making the experiment difficult to proceed.In this study,we analyzed the cause of this problem and implemented a series of effective measures to prevent similar issues from occurring in future tuning processes.Figure [45] Table [3] Reference [61]...