What is a synchrotron?
A synchrotron is a type of particle accelerator.
A particle accelerator is a type of machine that uses electromagnetic fields to accelerate charged particles to very high energies. A synchrotron is a type of particle accelerator used to accelerate protons for use in proton therapy treatment.
How does a synchrotron work?
A synchrotron is composed of a ring of small magnets. Protons are injected into the ring and begin traveling around the ring at about 10 million times per second. A radio frequency cavity within the ring increases the energy of the protons each time they travel around the ring. By varying the magnetic and electrical fields, synchrotrons can produce protons of various energies. Once the desired energy has been achieved, the protons are directed out of the synchrotron, into the beamline, and then directed at the tumor.
Due to a phenomenon called the Bragg Peak, the depth of penetration of the protons can be controlled to conform to the location of the tumor. Because the proton beam can be conformed to the shape and depth of the tumor, the exit dose that occurs with traditional photon therapy treatment, is eliminated, sparing surrounding organs and normal tissue from radiation exposure. This makes it possible for patients to receive higher doses, increasing the effectiveness of treatment.
Cyclotrons and synchrotrons are the two types of particle accelerators used in proton therapy treatment.
Like synchrotrons, cyclotrons use electromagnets to accelerate protons. However, unlike synchrotrons, cyclotrons require a beam degrader to deliver the protons at the desired energy for treatment.
Because a beam degrader is not required, the synchrotron has low secondary neutrons and scatter radiation, which lowers the risk of unnecessary and unwanted radiation to the patient and facility. Additionally, the synchrotron is the more energy efficient choice of the two particle accelerators. Add to that the cost savings of thick shielding wall installation and an easier installation, and the synchrotron becomes the top choice for proton therapy facilities.
Proton therapy technology is getting smaller. ProTom’s Radiance 330® Proton Therapy System has the smallest synchrotron footprint in the market. For a single treatment room, the Radiance 330® requires an area smaller than that of a basketball court. This space is able to accommodate not just the synchrotron and beamline, but also the treatment room, control room, and all necessary concrete shielding.
Interested in learning more about particle accelerators? Download our fact sheet.