There are significant differences between traveling wave acceleration and standing wave acceleration in linear accelerators, which are mainly reflected in the following aspects:
The propagation characteristics of waves:

Traveling wave acceleration: In traveling wave acceleration, radio frequency electromagnetic waves (RF waves) propagate along a straight accelerating tube. When RF waves pass through the acceleration gap, they interact with charged particles, transferring energy to the particles and accelerating them. RF waves enter at one end of the accelerator tube and leave at the other end, without forming reflections inside the tube.

Standing wave acceleration: In standing wave acceleration, RF waves are input from the middle of the acceleration tube and reflect back and forth between the two ends, forming standing waves. This means that RF waves form a stable electric field distribution inside the accelerating tube, and charged particles are accelerated in this stable electric field.

Acceleration efficiency:
In some cases, standing wave acceleration can have higher efficiency because it allows for the use of higher electric field gradients within the same length of the acceleration tube, thereby accelerating charged particles to higher energy.

Debugging and complexity:
Traveling wave acceleration: Due to the unidirectional propagation of RF waves, debugging is relatively simple and usually does not require complex wave reflection and standing wave formation mechanisms.
Standing wave acceleration: Precise control of RF wave reflection and standing wave formation is required, so debugging may be more complex. In addition, standing wave acceleration also needs to consider the phase stability of the wave and possible mode competition issues.

Particle beam mass:
Due to the stable electric field distribution provided by standing wave acceleration, it may be more suitable for experiments and applications that require high-precision control of particle beam quality.

Acceleration tube design:
Traveling wave acceleration: The design of the acceleration tube is relatively simple because it does not require consideration of wave reflection and standing wave formation.
Standing wave acceleration: The design of the accelerator tube needs to consider the input, reflection, and standing wave formation of RF waves, which may require more complex structures and designs.

Application scenario:
Different linear accelerator designs may choose traveling wave or standing wave acceleration based on specific application requirements. For example, for particles that require efficient acceleration to high energy, standing wave acceleration may be a better choice. For some accelerators that do not require high beam quality but require simple and stable operation, traveling wave acceleration may be more suitable.

Overall, both traveling wave acceleration and standing wave acceleration have their advantages and disadvantages in linear accelerators, and the choice of method depends on specific experimental requirements and accelerator design.