Design of HITFL injection and extraction high-voltage electrostatic deflector

According to the main parameters of Heavy Ion Therapy Facility in Lanzhou (HITFL), the physical model of injection and extraction deflector is built by ANSYS code which is a 3D program for electromagnetic field calculation. In the calculation, the fillet radius and the half width of the high voltage electrode are set to 20 mm and 55 mm respectively. From the result, the non-uniformity of electric field is from -0.24 percent to 0.24 percent, and the coefficient of electric field is 1.37(less than 2), so the design of the deflector meets physical requirement. According to the experience of CSRm deflector in HIRFL-CSR project, the deflectors of HITFL are made of wrought aluminum with surface anodic oxidation in order to meet the requirement of the resist pressure and the mechanical strength.