[Music] hi everyone my name is poine and as a nuclear medicine resident I work with radioisotopes on a daily basis but I have to admit that until recently I didn't really know how Cyclone was used to produce these radioisotopes I decided to change that and I went to one of the TXS and asked him for help this is what I learned a cyclotron is a type of particle accelerator that produces radioactive isotopes that can be used for Imaging procedures the cyclotron is made up of two Hollow d-shaped sheet metal electrodes known as the D's the
D's are placed face to face in a large metal container with a narrow gap between them creating a cylindrical space for particles to move air is removed from the large container so that the particles neither lose energy nor are deflected because of collisions with air molecules the apparatus is placed between the poles of a powerful electromagnet that provides a magnetic field the D are then connected to a high frequency voltage source that provides an alternating electric field in a small region between them this will attract and repel the ions so in summary the direction of
the electric field is horizontal while the direction of the magnetic field is vertical let's now have a look at how a cyclotron works at first the particle that needs to be accelerated is injected into the center of the space the electric field accelerates the charged particle and pushes it into the magnetic field region in the magnetic field region it completes a half circle without reducing its speed the magnetic field exerts a force perpendicular to the motion of the charged particle which helps to maintain a constant radius when it is inside the magnetic field region by
the time the part returns to the Gap the electric field has reversed so they are accelerated into the other D the particle gets a boost in energy every time it crosses the Gap causing it to accelerate this acceleration results in an increased velocity of the particle and this in turn will force the particle to move in a bigger circle after another half rotation the electric field in the region must be changed again so that a Charged particle can be accelerated again so so we use an alternating electric field where the frequency of the voltage is
set so that the particle makes one revolution during a single cycle of the voltage in other words the accelerating electric field reverses just at a time the particle finishes its half circle after repeating this process several times the radius of the high-speed particle reaches the radius of the cyclotron the particle will hit the extraction foil and it will be stripped of its electrons leaving a positively charged proton that then travels down a beam line toward the target when the high energy particle collides with a nucleus of an atom in the Target protons and or neutrons
are added or removed thereby changing the structure of the atom to create a radioisotope from stable non-radioactive atoms the radioisotope is then added to a molecule for example if we want to make fdg we have to produce fluorine h and incorporate this into a sugar molecule bombarding oxygen 18 with hydrogen ions result in a production of fluorine 18 and a neutron one more thing that I'd like to share with you is the difference between a synchrotron and a cyclotron remember that the electric field creates a force in a Charged particle and as such accelerates the
particle the magnetic field on the other hand constrains the charged particle to a circular or spiral orbit as the particle accelerates under the electric field its velocity increases causing it to move to a pad of increased radius to combat this the magnetic field is increased to keep it constrained to a circular orbit this requires the magnetic field to be kept in synchronism with increased velocity this is what happens in the synchrotron if the magnetic field is kept constant then the increasing velocity of the particle created by the electric field caus causes the particles to spiral
outwards this is what happens here in a cyclotron thank you so much for watching this video if you liked it please give it a thumbs up
