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The "Sniper Rifle" in Radiotherapy Equipment: The Accelerator Tube
The "Sniper Rifle" in Radiotherapy Equipment: The Accelerator Tube
Radiotherapy is recognized as one of the best treatment methods for tumors in the world, and the accelerator tube plays a vital role in the accuracy of radiotherapy equipment. It is like a sharp sword, which instantly cuts the continuous electron beam like a waterfall into uniform electron clusters, and finally "transforms" into a "barrel" and sends the bullet-like electron clusters to the "gun chamber"—an uninterrupted and precise attack on cancer cells hidden in the body.
Dec 22, 2021
Dec 22, 2021
Research & Design
How Can We Ensure Every Parameter Precise?
Throughout the world, there are no more than 5 manufacturers that can 100% independently develop and mass-produce accelerator tubes, and the entire process from design to production is as difficult as aerospace.
Accelerator tube design integrates high-precision interdisciplinary knowledge such as optics, dynamics, and electromagnetism, and the design considerations are extremely complex. To ensure rigour, the design process had to be elongated into several stages. Each stage needs to consider the direction, speed and energy output of the particles in different states. If the calculation deviation is large, the overall radiation dose will be affected, which will greatly reduce the effect. Only by establishing a large number of data models, carrying out rigorous derivation, and performing up to tens of thousands of repeated iterative calculations, can the stability of particles in the accelerating tube be ensured.
The Manufacturing Process
An accelerating tube is welded by 13 cavities, and the manufacturing processes are interlocked with each other, and the fault tolerance rate is 0. Any piece of cavity that does not meet the standard, the entire accelerator tube with extremely high cost will be directly scrapped. The cavity is extremely demanding and sensitive to the manufacturing environment. A slight fluctuation in temperature and humidity will cause the cavity to deform, resulting in abnormal particle beam output in the accelerating tube. The surface processing of the cavity is also very important. The nano-scale dust on the cavity will cause a sharp increase in the firing rate, affect the operation efficiency of the accelerator tube, and shorten the overall life of the radiotherapy equipment.
United Imaging Medical invested tens of millions to introduce several international top CNC lathes and milling machines with micron-level machining accuracy. The cavity has been polished for tens of thousands of times until it is as smooth and clean as a mirror. After polishing, it is sent to a dust-free clean room to remove nano-level impurities on the surface. Finally, it is sent to the protection area - the welding assembly room. Hydrogen is passed into the brazing furnace and heated to thousands of degrees, and the multiple cavities are vacuum welded in sequence.
First Self-Developed Medical Accelerator Tube Brings Hope
In July 2015, in Bunker, the first high-energy X-ray was shot from the self-developed accelerator tube and hit the target area precisely. It has been verified several times that all indicators can reach the mass production level - United Imaging Healthcare's first self-developed medical accelerator tube that can be mass-produced was born.
Based on this, the world's first integrated CT-linac 506c came out. It has been put into use in well-known tertiary hospitals such as Shanghai Fudan University Cancer Hospital, Sun Yat-Sen University Cancer Center, Wuhan Zhongnan Hospital, etc., providing tens of thousands of patients with precise radiotherapy.