摘要：The physical design and cooling test of a C-band 2MeV standing wave （SW） accelerating tube are described in this paper. The designed accelerating structure consists of 3-cell buncher and 4-cell accelerating section with a total length of about 163mm, excited with 1MW magnetron. Dynamic simulation presents that about 150mA beam pulse current and 30% capture efficiency can be achieved. By means of nonlinear Gauss fit on electron transverse distribution, the diameter of beam spot FWHM （full width at half maximum of density distribution） is about 0.55mm. Cooling test results of the accelerating tube show that frequencies of cavities are tuned to 5527MHz and the field distribution of bunching section is about 3：9：10.

摘要：The sandwich transducer structure is comprised of threecomponents along its main axis: the back metal cap, piezoelectricceramic stack and the horn. The purpose of this work is topresent a simplified method, referred as the equivalent lengthalgorithm, to design the actuator parameters including eachsegment length and the resonance frequency fs. The actuatorlength L and the propagation wavelength λ along its main axissatisfy the standing wave theory. So, define an equivalent lengthcoefficient for each part of the actuator, and then the sandwichstructure is regarded as a single material cylindrical rod withequivalent length L′. According to the standing wave theory, theequivalent length L′ of the actuator can be determined with thegiven resonance frequency fs, or vice versa. The phase length ofeach part of the actuator in the standing wave is optimized freelyin the design procedure. The actual length of each part of theactuator is determined by the equivalent length ***, the resonance frequencies of three given actuators arecalculated with this method. They are compared with thoseobtained through Ansys simulation and those measured by animpedance analyzer. The results show agreement.

摘要：This paper presents and verifies a new idea for constructing an ultrasonic motor （USM）. The stator contains several vibrators fabricated by bonding piezoelectric ceramics （PZTs） to a metal base. When two alternating current （AC） voltages with a 90° phase difference are applied to the PZTs, longitudinal and bending modes are excited in the vibrator. The bending vibrations of the vibrators are stacked to form the torsional vibration of the stator, ultimately generating longitudinal-torsional composite vibration. Both vibrators and the stator are excited to the resonance state. A standing wave is formed by superposition of longitudinal and torsional modes. The proposed motor is an in-plane vibration motor because the vibrations of the stator are in the circumferential plane. The finite element method （FEM） is used to validate the feasibility of the proposed motor. The fabricated stator contains five vibrators. The tested resonance frequencies of longitudinal and torsional modes are 44.42 kHz and 43.83 kHz, respectively. The stall torque is 0.3 N＇m and no-load speed is 45 r/min. The highest efficiency is 30%. The applied driving voltage is 100 Vo.p （peak voltage） at 43.9 kHz. The designed motor is a parallel-actuated integral motor. It allows the vibrators to operate synchronously, and overcomes asynchronous issues that occur in traditional multi-vibrator motors.