What is Proton beam: Definition and 19 Discussions

A charged particle beam is a spatially localized group of electrically charged particles that have approximately the same position, kinetic energy (resulting in the same velocity), and direction. The kinetic energies of the particles are much larger than the energies of particles at ambient temperature. The high energy and directionality of charged particle beams make them useful for applications (see Particle Beam Usage and Electron beam technology).
Such beams can be split into two main classes:

unbunched beams (coasting beams or DC beams), which have no longitudinal substructure in the direction of beam motion.
bunched beams, in which the particles are distributed into pulses (bunches) of particles. Bunched beams are most common in modern facilities, since the most modern accelerator concepts require bunched beams for acceleration.Assuming a normal distribution of particle positions and impulses, a charged particle beam (or a bunch of the beam) is characterized by
the species of particle, e.g. electrons, protons, or atomic nuclei
the mean energy of the particles, often expressed in electronvolts (typically keV to GeV)
the (average) particle current, often expressed in amperes
the particle beam size, often using the so-called β-function
the beam emittance, a measure of the area occupied by the beam in one of several phase spaces.These parameters can be expressed in various ways. For example, the current and beam size can be combined into the current density, and the current and energy (or beam voltage V) can be combined into the perveance K = I V−3/2.
The charged particle beams that can be manipulated in particle accelerators can be subdivided into electron beams, ion beams and proton beams.

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  1. B

    I Focused proton beam waist diameter

    According to this link (https://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/collisions.htm) the LHC achieves a beam waist diameter of approximately 64 microns. What limits them from getting a tighter focal point? Are lower energy beams easier or harder to focus tightly?
  2. B

    Parallel Plate Pulsed Proton Beam Generator (Thought Experiment)

    I am trying to come up with a design for a device with which to generate a rapidly pulsed proton beam (on the order of 1 pulse per ms). My thought was to apply a 10 kV potential between two parallel plates (each with a hole in their center) and inject a steady stream of hydrogen gas through the...
  3. B

    Can energy be extracted from a proton beam using a current transformer?

    Suppose there exists a proton beam that is pulsed on and off. If this beam is aimed through a current transformer as in the attached image (the proton beam would act as the main primary conductor in this case), what would be the output of the transformer, and how would it affect the beam...
  4. E

    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...
  5. M

    Volume Charge Density of Proton Beam

    Homework Statement 1.0 mA proton beam accelerated through potential difference of 1 keV. Determine the volume charge density of the beam after acceleration assuming uniform current distribution within diameter of 5mm, with zero current outside of this. Particle starting from rest. Final answer...
  6. C

    Wavefunction normalisation for proton beam

    Homework Statement Calculate the normalization parameter A in the wavefunction ## \varPsi(x,t) = A e^{i(k\chi - \omega t)} ## for a beam of free protons traveling in the +x direction with kinetic energy 5 keV and a density of ##7.5 * 10^9 ## particles per meter beam length. Homework...
  7. F

    Questions on Proton Beam Experiment at CERN

    Hello everybody. I am going to propose an experiment with a proton beam at CERN for a contest. http://home.web.cern.ch/students-educators/spotlight/2013/competition-beam-line-schools. Also...
  8. K

    Threshold energy of proton beam?

    Homework Statement I am trying to find the minimum energy for a proton beam to make pions that have 100Gev of momentum. The proton beam is hitting a fixed target. Homework Equations p + n -> n + n + ##π^{+}## The Attempt at a Solution In the centre of mass frame, there is zero...
  9. W

    Calculating Activity of proton beam

    Homework Statement A natural lithium target 3.8 mg cm-2 thick is bombarded with a 125 µA beam of 3.5 MeV protons initiating a 7Li(p,n) reaction. Assuming a reaction cross section of 300 mb, calculate the activity produced by a 15 minute bombardment. Homework Equations...
  10. 1

    High energy proton beam collimation

    Hi all, my question is not strictly related with physics and I don't know if it is the right section. Anyway I have a problem with a collimator: I need 100micron (or maybe smaller) collimator, but the high energy (60-70 MeV) of the beam need a material which is at last 5mm thick, (tungsten...
  11. O

    Particle Accelerator problem with a proton beam hitting a target

    Homework Statement In a certain particle accelerator, a current of 300μA is carried by a 4.00-MeV proton beam that has a radius of 1.30 mm. The mass of a proton is 1.67 x 10-27kg. If the beam hits a target, how many protons hit the target in 3s? Homework Equations The only equation that...
  12. B

    Proton Beam Elemental Transmutation

    I was reading about Earnest Lawrence and a question dawned onto me; Let's say you bombarded a metal, let's say iron or copper, with high energy protons coming from a cyclotron. The protons going from the "dees" into an accelerating vacuum tube with the specimen at the end. Would the proton beam...
  13. G

    Deflecting high energy proton beam

    hi everyone, I have a question concerning the magnets physics more precisely about the Kickers/Dipoles. For my work, I need to design an optical system capable of deflecting a proton beam (4 GeV) switching between to 2 angles (+ 118 mard and -118 mrad) in a raw. Can a pulsed magnet...
  14. S

    Magnetic Fields proton beam accelerated

    Homework Statement A beam of photons, originally at rest, is accelerated horizontally between the plates of a parallel-plate capacitor, the potential difference of which is 1000 V and has a separation of 1.0 cm. The particle enters a region wher a uniform magnetic field, B=0.913T (directed out...
  15. P

    Magnetic Fields and Proton Beam therapy

    Proton Beam therapy is an advanced technique to destroy tumors by concentrating a high energy beam of protons to a specific depth inside the body of a patient. These proton beams are produced by accelerators and steered to the patient-treatment rooms by magnets. In a particular cancer treatment...
  16. S

    Relativity proton beam relative velocity problem

    hi guys I am new to this forum so this is my first post would appriciete some help with this problem Homework Statement in a colliding beam experiment, in a laboratory frame equal and opposite velocity proton beams collide. the relative velocity of the beams is 2.99 x 10^8 m/s, calculate...
  17. M

    Protons delivered per second in a proton beam

    Homework Statement a 5.0 mm-diameter proton beam carries a total current of 1.5mA. the current density in the proton beam, which increases with distance from the center, is given by j=j(edge)(r/R), where R is the radius of the beam and j(edge) is the current density at the edge. a) how many...
  18. T

    Proton Beam therapy (magnetic field)

    Homework Statement A beam of protons with v=1.8x10^8 are deflected 90 degrees by a constant magnetic field. The trajectory of the beam has a circular arc with a radius of 4m. I am asked to find the magnitude of the constant magnetic field. Homework Equations I know that r=mv/eB. When...
  19. S

    Surface Charge Density and high-speed proton beam

    You have a summer intern position at a laboratory that uses a high-speed proton beam. The protons exit the machine at a speed of 2.10 times 10^6 m/s, and you've been asked to design a device to stop the protons safely. You know that protons will embed themselves in a metal target, but protons...