# What is Cyclotron: Definition and 99 Discussions

A cyclotron is a type of particle accelerator invented by Ernest O. Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. A cyclotron accelerates charged particles outwards from the center of a flat cylindrical vacuum chamber along a spiral path. The particles are held to a spiral trajectory by a static magnetic field and accelerated by a rapidly varying (radio frequency) electric field. Lawrence was awarded the 1939 Nobel Prize in Physics for this invention.Cyclotrons were the most powerful particle accelerator technology until the 1950s when they were superseded by the synchrotron, and are still used to produce particle beams in physics and nuclear medicine. The largest single-magnet cyclotron was the 4.67 m (184 in) synchrocyclotron built between 1940 and 1946 by Lawrence at the University of California, Berkeley, which could accelerate protons to 730 mega electron volts (MeV). The largest cyclotron of its kind is the 17.1 m (56 ft) multimagnet TRIUMF accelerator at the University of British Columbia in Vancouver, British Columbia, which can produce 520 MeV protons.
Close to 1500 cyclotrons are used in nuclear medicine worldwide for the production of radionuclides.

View More On Wikipedia.org
1. ### Calculations for accelerating particles in a Cyclotron

For this question part d, KE=mv^2/2=q^2B^2r^2/2m (I rearranged B=mv/qr for v and subbed into mv^2/2). q^2b^2r^2/2m=2F_cyc^2r^2m(pi)^2 But when I subbed the values in I got 16.45MeV but the answer says 165keV instead. I'm not sure what went wrong? What's a good explanation for part e also?
2. ### Max speed of proton in cyclotron

For this problem, The solution is, However, I don't understand why they say just before the proton escapes? Are they assuming that the B-field is only at a portion of region which means that only half or so of the circular path is within the B-field so only half of the path have a magnetic...
3. ### I Hall Effect constant and Cyclotron frequency

In the ch1 if solid state physics Mermin & Ashcroft, in the hall effect section these paragraph are about cyclotron frequency, but what the two last terms want to say(the screen shot of the page is attached)? And I can't understand what happens to hall constant in high-field regime?
4. ### I Why does a cyclotron only impart linear momentum?

I read the Wiki page https://en.wikipedia.org/wiki/Electron_cyclotron_resonance as well as this answer here How does a cyclotron work? and it describes a setup where one has a cyclotron which has a static magnetic field pointing up through the dees and there is an alternating high voltage...
5. ### Cyclotron - Vacuum Chamber Materials

Hi all! So recently me and a group of friends have begun working towards the construction of a cyclotron - and I was wondering, if anybody here would have an idea what kind of materials would be able to be used for the vacuum chamber that aren't specific Aluminium Alloys such as 7075 or 6061...
6. ### Solve Cyclotron Motion Homework

Homework Statement An electron in a cathode-ray tube is accelerated through a potential difference of 10 kV, then passes through the d = 2.4-cm-wide region of uniform magnetic field in the figure. Homework Equations - Am I taking the entirely wrong approach in the solution? The Attempt at a...
7. ### Solving a Disappearing Voltage Puzzle: The Ball Cyclotron Project

Homework Statement I'm making a ball cyclotron (https://rimstar.org/science_electronics_projects/ball_cyclotron_electrostatic_accelerator.htm) for a school project. To generate enough voltage, I'm using a Van der Graaf-generator. The problem is that all the voltage, which I can measure...
8. ### Can there be collision-less acceleration of electrons?

In electron cyclotron resonance of metals/solids can there be electron acceleration without them engaging in collision ? I read the last para of electron cyclotron resonance wikipedia page which stated this
9. ### Proton nuclear simulation issue (MCNP6)

Hi, I'm simulating in MCNP6 the reaction of proton beam on targets but in the simulation the 96% of the proton are lost for energy cutoff. I don't understand why happen that. I use a tally4 to obtain the reaction in the target, but I suppose the results are wrong because the lost of protons (if...
10. ### Cyclotron Frequency: Is it Truly Independent of Energy and Mass?

Do cyclotrons make use of the principle that the cyclotron frequency is independent of energy?
11. ### I In PET scanners, why is a cyclotron used to make positrons?

Why could you not use a non-linear accelerator, like the LHC (but obviously nowhere as big)? Would it non be able to produce positrons more quickly because it can obtain larger fractions of the speed of light in a smaller period of time?
12. ### I Can You Really Build a Cyclotron for \$17?

I was at CERN and remember reading somewhere that it is possible to build a cyclotron for the price of 17 US dollars, if anyone has any useful links they could send my way (to blueprints or useful diagrams, it would be much appreciated thank you) :)
13. ### Cyclotron Radius of Proton: .625m

Homework Statement The cyclotron radius of a proton moving at 3.0*10^5 m/s perpendicular to a 5*10^-6T magnetic filed is: Homework Equations r=mv/qB The Attempt at a Solution So plug and chug: r= (1.6*10^-27)(3*10^5)/(1.602*10^19)(5*10^-6) r=625.5m However they have it down as .625m. Where...
14. ### I Cyclotron resonance and Landau Levels

I'm trying to understand cyclotron resonance measurements of electron effective mass in intrinsic silicon. I need to understand the theory used to make the computations of effective mass in non-parabolic bands. A basic introduction to the cyclotron technique is here, but only for parabolic...
15. ### B Is a 2 Tesla magnetic field strong enough for a 5cm cyclotron design?

I'm trying to work out what velocity and magnetic field strength one needs to capture the charged particle in a circle of comfortable lab size - say 5cm ( 0.05m). For a sodium ion ( mass = 3.8175407 × 10-26 kg) with charge q = 1.60217653 x 10 -19 , velocity 183234 m/s, C in a magnetic field...
16. ### Resonance condition of a cyclotron.

the charged particle undergoes acceleration because of the presence of electric field between the two Dee. as a result the electric field needs to change it's direction according to the motion of the charged particle. since the time period of the charged particle does not depend upon the...
17. P

### B In a cyclotron, the time to make it all the way around is Different

Can I apply the formula t= gamma * t' if the path is Circular?
18. P

### New user here, Need direction and help before my end....

It has been over 15 years since I completed a Masters of Science in Electrical Engineering. However that alone does not really date me much. So far I have yet to find a source of employment that lasts long enough or is of enough compensation to pay off student loans before I can even begin to...
19. ### What is the estimated path length traveled by a deuteron in a cyclotron?

Homework Statement Estimate the total path length traveled by a deuteron in a cyclotron of radius 53 cm and operating frequency 12 MHz during the entire acceleration process. Accelerating potential between dees is 80 kV. mass m = 3.2e-27 kg charge q = 1.6e-19 C radius r = 0.53 m frequency f =...
20. ### A Usefulness of a low energy cyclotron

I'm exploring building a very small basement cyclotron. I have a solid professional electrical engineering background; the only major new technology for me would be the ultra-high vacuum, so I think it's at least possible. I've been going through Humphries' Principles of Charged Particle...
21. P

### Ray gun from call of duty zombie?

Can a ray gun be created? What would it fire? plasma? I know that the dimendion of the ray gun are too short for what am i going to say, but i want to ask if aside this problem this could work: I thought that maybe the things that you put in the ray gun to charge it are batteries, and that the...
22. ### Calculating Proton Energy in a Cyclotron

Homework Statement A proton is accelerated to an energy 5Mev in a cyclotron with AC pd of 1KV and the frequency of 8MHz applied to dees. Calculate the number of times proton would have to pass the dees to reach the energy 5MeV? Homework Equations F=BQV=MV^2/r The Attempt at a Solution...
23. ### B Necessity of D's in a Cyclotron

Are the D's necessary in a cyclotron? It seems to me that the same effect could be achieved without the discontinuity, which would eliminate the need for a high operating voltage. If the D's are replaced by a complete conducting circle of metal, you could just apply the alternating voltage to...
24. ### Cyclotron magnetic field questions

Homework Statement Cyclotrons are widely used in nuclear medicine for producing short-lived radioactive isotopes. These cyclotrons typically accelerate H− (the hydrideion, which has one proton and two electrons) to an energy of 5MeV to 20MeV. This ion has a mass very close to that of a proton...
25. ### What is a Synchronised cyclotron?

Hey so help me out here please. This is an Edexcel Physics A2 question (I'm doing A Levels). I really don't know if this will make sense at all lol So there are cyclotrons- where the mass of the particle must me constant, that is, the limitation of the cyclotron is that it does not take into...
26. ### Difference between betatrons and cyclotrons

Hello, I was wondering if anyone would be able to tell me the key differences between a betatron accelerator and a cyclotron accelerator. Thanks :)
27. ### A electron cyclotron has a frequency of 2450 Hz and a magnet

Homework Statement A electron cyclotron has a frequency of 2450 Hz and a magnetic field strength of 50T.? a) what's the speed of the electron? b) what was the voltage on the electron gun which projected the electron into the cyclotron? Homework Equations Givens: r=.4m B=50T f=2450Hz...
28. ### Understanding Cyclotron Oscillations Frequency

I am having trouble making sense of the frequency of oscillations for a cyclotron. What I don't understand is, if a the voltage difference of the two dees is switched twice ( each time the particles are about to enter them), then why is the frequency of oscillation the same as the frequency at...
29. ### Where does the proton come from in a Cyclotron?

Where does the proton come from in a Cyclotron?
30. ### Exploring the Mystery of Zero Electric Field Inside a Cyclotron

The E-field originating from the opposite surfaces (above and below) cancel out one another but what about the fields originating from the circular sides? Why is the electric field inside the cyclotron zero then?
31. ### Cyclotron Resonance: Lower Limit for Electron Scattering Time

Homework Statement Calculate the lower limit of the electron scattering time in a material placed in a magnetic field of 1 T which is necessary to observe cyclotron resonance. The electron effective mass in the material is 0.06 ##m_o## (where ##m_o## is the free electron mass).Homework...
32. ### Cyclotron Motion Due to Earth's Magnetic Field

1. Say that an electron is heading towards the Earth from the sun with an initial known velocity v. And we know that at Earth's surface the magnetic field is given by B1. This B varies as (R1/R2)^2 where R1 is the radius of the earth. How can I find the location in space, R3/R1, where R3 is the...
33. ### Why Does Cyclotron Frequency Depend Only on Magnetic Field Strength?

According to the equation F=BQ/2pieM the frequency depends on the magnetic field and not the speed or radius of the particle. Can someone please explain why? B= Magnetic field strength Q=Charge M=Mass I think it's because of the force felt due to magnetic field so the time it reaches the dees...
34. ### Calculating magnetic field to accelerate deutrons in a cyclotron

Homework Statement A cyclotron has oscillator frequency of 12×10^6 cycles /sec and dee radius 21 inches .Calculate the magnetic induction B needed to accelerate deutrons . Given e=1.6 ×10^-19 coulomb and M (21H )=3.3×10^-27 kg. Homework Equations Frequency f= Bq/2πΜ The Attempt at a Solution...
35. ### Calculating Cyclotron Exit Energy: Tips for Operator

So, I'm beggining to work in a cylcotron as operator. Most of the crew here has technical education, albeit not quite a physics degree. When i asked what's the distribution of energies of the particles when they hit the target i got a blank look. How could i determine this? I'm guessing that...
36. ### Cyclotron - relationship between velocity and radius

cyclotron -- relationship between velocity and radius in a cyclotron the radius of the path of electron increases.but how if the velocity of the electron is accelerated its kinetic energy should only increase but why is it's radius increasing despite the fact that it's moving to the dee with...
37. ### Optical thickness of the second harmonic cyclotron motion in a plasma

Homework Statement Let's consider a Tokamak with major radius R=1m and minor radius a=0.3m, magnetic field B=5T with a deuterium plasma with central density 10^{20}m^{-3}, central temperature 1keV and parabolic temperature and density profiles \propto (1-r^2/a^2) a) Find the electronic...
38. ### Interpretation of cyclotron resonance data

Homework Statement Compare the cyclotron resonance signal from Silicon in figure 28.9b (in Ashcroft and Mermin) with the geometry of the conduction band ellipsoids shown in figure 28.5, and explain why there are only two electron peaks although there are six pockets of electrons. Homework...
39. ### Cyclotron Radiation: Charged Particle Kinetic Energy

If I have a charged particle traveling into a constant B field it will bend its path and emit cyclotron radiation. If a magnetic field can't do work then what caused the charged particle to change its kinetic energy. I guess if I was in the electrons rest frame their would be an E field in...

both involve a charge carrier undergoing centripetal acceleration thereby producing radiation from the acceleration; so what's the difference?
41. ### Why is the electric field zero inside the DEES of a cyclotron?

why is the electric field zero inside the DEES of a cyclotron?
42. ### Cyclotron: Why Electric Field Inside Dees is Zero

why electric field inside the dees of a cyclotron is zero
43. ### Find first and second harmonics of the electron cyclotron frequency.

Homework Statement Give expressions for the first and second harmonics of the electron cyclotron frequency. Homework Equations Gyration frequency is ωB = (eB) / (mec) Interval between cyclotron lines is Δv = (eB) / (2∏mec) The Attempt at a Solution I think that (although my...
44. ### Building a Cyclotron: Learn, Ask and Find Equipment

Hello everyone, I'm very interested in building a cyclotron as a learning experience over the next year or so and have been doing some reading on what's required. I figure it would be helpful to ask everyone's opinion on materials such as electromagnets, beam detectors, vacuum cambers, etc. I'm...
45. ### Solve Cyclotron Question: Calculate Magnetic Field & Time to Exit

Homework Statement If a cyclotron with a maximum chamber radius of 110 cm can accelerate ##_{4}^{2+}He##, (alpha particles) up to a energy of 140 MeV, calculate A) The magnetic field and comment on your answer. If the accelerating voltage is 3 kV and the source of alpha particle is...
46. ### Where Does the Energy of Cyclotron Radiation Come From? Solving the Paradox

Description of the paradox: We have a charged ring, which rotates at high speed. Since rotating charges produce cyclotron radiation, it emits photons. There is a toroidal mirror around the ring, spinning together with it. The mirror reflects the photons back inside, preventing them from...
47. ### Solving Cyclotron Resonance: Azbel-Kaner Method

Hi, I am a new member. May you help me with this problem? In Azbel-Kaner cyclotron resonance, a B field is placed parallel to the sample surface to make cyclotron motion, an oscillation electric field is place to induce resonance. There is a link about this...
48. ### Derive cyclotron and synchrotron frequency

I am trying to find out how to derive the cyclotron and synchrotron frequency, but everywhere I look it is derived by saying that the force of the magnetic field is not qvB, but (v/c)qB. What on Earth is this c? I am guessing it means speed of light but then it is not the case that (v/c)qB =...
49. ### Energy inside a cyclotron, and the frequency of circular motion

Homework Statement One of the first cyclotrons, built in 1932, has D-s with a diameter of 28 cm, and its magnet was capable of producing magnetic field of 1.4 T. What is the maximal energy of the protons accelerated by this cyclotron? What is the frequency of the circular motion?Homework...
50. ### Building a cyclotron - tips/ideas

Hello! I am interested in building a cyclotron. Since I doubt that I will be compotent enough to build a cyclotron right now, what are some tips that you can give me to get me started on the (long) process towards building a cyclotron. I understand the several dangers - I am interacting with...