Flash Therapy

There is emerging evidence that very high dose rates, referred to as Flash therapy, can provide significant benefits when using radiation for cancer treatment. Normal clinical linear accelerator (linac) operation delivers a dose rate about 10-2Gy/s. The objective of this project is to design a device that will allow Flash Therapy which involves the modification of a linac to deliver 40- 150Gy/s [1] in 1s bursts.

This 400-1500 fold increase in dose rate can be achieved by increasing the gun current. The linac operates in pulsed mode with the pulses provided by a thyratron switch. Thyratron trigger pulses continue until a set dose is delivered. The trigger pulses are 3μs in length and spaced 2.5ms apart for 400 pulses/s or 5ms apart for 200 pulses/s. In order to deliver a high dose for one second the trigger pulses need to be counted and their delivery interrupted once the set condition is met.