- Barty, Christopher PJ;
- Algots, J Martin;
- Amador, Alexander J;
- Barty, James CR;
- Betts, Shawn M;
- Casteñada, Marcelo A;
- Chu, Matthew M;
- Daley, Michael E;
- De Luna Lopez, Ricardo A;
- Diviak, Derek A;
- Effarah, Haytham H;
- Feliciano, Roberto;
- Garcia, Adan;
- Grabiel, Keith J;
- Griffin, Alex S;
- Hartemann, Frederic V;
- Heid, Leslie;
- Hwang, Yoonwoo;
- Imeshev, Gennady;
- Jentschel, Michael;
- Johnson, Christopher A;
- Kinosian, Kenneth W;
- Lagzda, Agnese;
- Lochrie, Russell J;
- May, Michael W;
- Molina, Everardo;
- Nagel, Christopher L;
- Nagel, Henry J;
- Peirce, Kyle R;
- Peirce, Zachary R;
- Quiñonez, Mauricio E;
- Raksi, Ferenc;
- Ranganath, Kelanu;
- Reutershan, Trevor;
- Salazar, Jimmie;
- Schneider, Mitchell E;
- Seggebruch, Michael WL;
- Yang, Joy Y;
- Yeung, Nathan H;
- Zapata, Collette B;
- Zapata, Luis E;
- Zepeda, Eric J;
- Zhang, Jingyuan
The design and optimization of laser-Compton x-ray systems based on compact distributed charge accelerator structures can enable micron-scale imaging of disease and the concomitant production of beams of Very High Energy Electrons (VHEEs) capable of producing FLASH-relevant dose rates. The physics of laser-Compton x-ray scattering ensures that the scattered x-rays follow exactly the trajectory of the incident electrons, thus providing a route to image-guided, VHEE FLASH radiotherapy. The keys to a compact architecture capable of producing both laser-Compton x-rays and VHEEs are the use of X-band RF accelerator structures which have been demonstrated to operate with over 100 MeV/m acceleration gradients. The operation of these structures in a distributed charge mode in which each radiofrequency (RF) cycle of the drive RF pulse is filled with a low-charge, high-brightness electron bunch is enabled by the illumination of a high-brightness photogun with a train of UV laser pulses synchronized to the frequency of the underlying accelerator system. The UV pulse trains are created by a patented pulse synthesis approach which utilizes the RF clock of the accelerator to phase and amplitude modulate a narrow band continuous wave (CW) seed laser. In this way it is possible to produce up to 10 μA of average beam current from the accelerator. Such high current from a compact accelerator enables production of sufficient x-rays via laser-Compton scattering for clinical imaging and does so from a machine of "clinical" footprint. At the same time, the production of 1000 or greater individual micro-bunches per RF pulse enables > 10 nC of charge to be produced in a macrobunch of < 100 ns. The design, construction, and test of the 100-MeV class prototype system in Irvine, CA is also presented.