Questions tagged [accelerator-physics]

is appropriate for questions dealing with the physics of beams in accelerators (synchrotrons, cyclotrons, linacs, betatrons and other types of accelerators); the ways in which beams are generated; the accelerating, bending and focusing equipment; and the intrinsic limits that arise in trying to manipulate beams. DO NOT USE THIS TAG for questions that concern the use of the particle beams once they arrive in the experimental hall.

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What happens in a particle accelerator? [closed]

How is the particle accelerated? Is it by increasing its energy? Is it only charged elementary particles that can be accelerated, because they are the only ones that can absorb photons and gain energy?...
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In simple English what is meant by "tagging", "triggering", "selection criteria" and "reconstructed events/particles/masses" in particle physics? [closed]

I am currently reading the original Higgs boson discovery paper, "Observation of a new boson at a mass of $125$ GeV with the CMS experiment at the LHC", HIG-12-028, which can be found ...
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On RF cavities in circular accelerators

Radiofequency pillbox-like cavities are used to accelerate particles, as shown here. They act grossly speaking like a LC circuit, so they are designed to work with a specific frequency. This already ...
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On Mandelstam variables

Citing Wikipedia: $[\dots]$ the Mandelstam variables are numerical quantities that encode the energy, momentum, and angles of particles in a scattering process in a Lorentz-invariant fashion. They ...
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Why does a magnet arranged in a magnetic accelerator propogate a wheel forward?

My question is related to an interesting video i saw on magnets. The link of the video is here https://youtu.be/iyv9GhaITNE , in this video at 1:52 of the video we see the wheel is moved forward but i ...
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Fission is to Cyclotrons as Fusion is to _________?

Using a cyclotron we can trigger fission in a controlled way. My question is similar to cyclotrons, do we have a mechanism in which we can trigger fusion from a physics (non-chemistry) perspective ...
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Does an einzel lens draw current?

I was trying to think about the physics of a single particle in an Einzel lens. As it enters the lens, it would draw negative current, and then as it leaves the lens, it would draw positive current. ...
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Potential difference in dipole antenna :

Can some one explain this concept in dipole antenna that how potential difference is working? And it is correct to say when connected to the ac source positive charges move to one pole and negative ...
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Has there been an experiment with entangled particles to observe effect on decay time when one is at relativistic speed? [closed]

Has there been an experiment with entangled particles, two of the same, for example two neutrons, where one is left mostly at rest and the other accelerated to relativistic speed to observe if any ...
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Relativistic motion in particle accelerator

This question is attempting to simulate the process of a circular particle accelerator. We are given a constant electric field $E$ along the angular direction and a varying magnetic field $B$ along ...
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Molecular accelerators

I wanted to know if we have accelerators for molecules just like particle accelerators. If so, what are they called and what is the maximum size of the molecules that can be accelerated in such ...
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Does a low-gain free electron laser (FEL) emit coherent radiation?

For the low-gain free electron laser (FEL), an external field is injected into an undulator alongside an electron bunch. Due to phase slippage (because the light is faster than the electrons) the ...
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How long does the LHC take to accellerate a particle to its full speed? How long would a linear accellerator have to be to reach the same energies?

I'm wondering how long it takes the LHC to accelerate particles from rest to their top speed at 6.5 TeV. And related, how long a hypothetical linear accelerator would have to be to accelerate ...
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How can i shoot accelerated electron directly into the air?

I am trying to do an experiment in which I have to first accelerate the electron to 10eV and then shoot into the air directly. I need some kind of membrane which allows electron to pass and keep ...
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How does a booster work in a particle accelerator like the LHC?

In the proton synchrotron booster (PS) booster at the LHC, protons are accelerated from $50 \, \text{MeV}$ to about $1.4 \,\text{ GeV}$. This takes about a second to accomplish. Since the radius of ...
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How do we derive the components of the magnetic vector potential from a known magnetic field?

The magnetic field is $\vec{B}(r,\theta)=B_{0} \cdot[1+\mu(r)] \cdot [1+f(r,\theta)]\hat{e}_{z}$ where $f(r, \theta)=\sum_{n}\left[a_{n}(r) \cos n \theta+b_{n}(r) \sin n \theta\right]$, and $\mu(r)$ ...
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Can muons be used to reach the island of stability of superheavy elements?

While reading about the island of stability of superheavy elements[0], experimental approaches and related difficulties[1], an idea has formed in my head. Since I cannot find considerations of such ...
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Why can the neutron not be measured in this fixed-target experiment?

Consider a fixed-target-experiment, where negatively charged pions are shot at protons (the latter being at rest). The kinetic energy of the pions shall be known. One possible reaction is $$ \pi^- + p ...
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Why are edge fields in undolators necessary to comply with Maxwell?

In our lecture scripts there is a paragraph about the magnetic field of an undulator: "Its [the undulators] magentic field can be described by \begin{equation} \vec{B}\equiv-B_0 \begin{pmatrix} ...
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Can neutrons be manipulated with magnetic fields? Can neutron particle accelerators be built?

Neutrons have no electric charge and do not respond to electric fields as in a conventional particle accelerator. However, they are magnetic and do have a small magnetic dipole moment. So it should ...
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In a synchrotron, do electrons make periodic recoils?

Synchrotron radiation happens because circular motion of electrons produce a tangential acceleration-- or something along those lines. Point is, photons are produced by these accelerated electrons. As ...
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Radiation in particle accelerators

I was reading about particle accelerators in Wikipedia and I came across this. Depending on the energy and the particle being accelerated, circular accelerators suffer a disadvantage in that the ...
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Using something like a linear accelerator, could a visible object to accelerated to thousands of miles per second?

I am wondering what problems would arise using the same process that accelerates protons, etc. on something as large as a bb or maybe just a grain of sand. Not sure the practical reason for this but ...
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How many atoms does a relativistic ion dislodge?

Given a large chunk of some hard, refractory material e.g. graphite, diamond, tungsten, at low temperature surrounded by vacuum, and an impacting relativistic ion – to be specific, say an alpha ...
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Electron gun voltages

I saw on the internet that catode of electoron gun should have negative potential to zero (ground). On the other hand catodes of tv CRTs were grounded and anodes were connented to positive high ...
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What is meant by spatial resolution in a particle detector?

I'm reading a document about a particle physics detector and its sub-detectors. They mention that: ' its drift chamber has a spatial resolution of 130 μm'. Can anyone please explain to me what is ...
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How is the nucleus-nucleus CM energy per nucleon related the proton-proton CM energy in a circular accelerator?

If I understand it correctly, the center of mass energy per nucleon pair in heavy ion collisions is given by $$\sqrt{s_{NN}}=\sqrt{(p_a/A_a+p_b/A_b)^2},$$ where $a$ and $b$ label each colliding nuclei,...
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Collision Energy for heavy ions

I found this formula in Sahoo Relativistic Kinematics: $$\sqrt{s_{NN}}=2\sqrt{s_{pp}}+\sqrt{s_{pp}}\sqrt{\frac{Z_{1}Z_{2}}{A_{1}A_{2}}}$$ But because English isn't my first language i got confused. So ...
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Can I destroy Bennu, if I shoot it with my electron gun? [closed]

The asteroid Bennu seems to be just a pile of rubble weakly held together by gravitational forces. Newton’s law, -Gm1m2/r2, and Coulomb’s law, +keq1q2/r2, have exactly the same form but opposite sign. ...
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Polarized proton beam

Can someone explain to me or point me towards some references about how can one obtain experimentally a polarized proton beam. I find many talks about using siberian snakes to preserve the ...
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Which one is more efficient in producing high energy gamma rays?

According to https://apps.dtic.mil/dtic/tr/fulltext/u2/a351472.pdf the big pulsed power accelerator, HERMES III, generate electron beam with peak energy at 22 MeV and average electron energy at 16 MeV ...
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Generating very large area gamma rays by other ways other than large accelerators

According to this link https://apps.dtic.mil/dtic/tr/fulltext/u2/a351472.pdf, HERMES III at Sandia National Labs can generate very large area gamma rays by converting the electron beam into ...
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Functionality of an Einzel lens

An Einzel lens is a device for ion optics to focus a beam of particles. It consists of three ring electrodes, with the outer ones being on earth potential and the middle one being on high voltage (see ...
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Dirft Tube Linac Diameter

How to calculate dirft tube cavity diameter. Why it's so big. For electromagnetic frequency?
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When we use magnets in linear accelerators?

I'm searching particle accelerators. I couldn't see focusing magnets in Linear accelerators. When we need focusing magnets in Linacs? I'm sharing some photos of what ı found.
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Do particle accelerators have to adjust for the sun's gravity due to length contraction?

I believe particle accelerators move atoms at 99.999% the speed of light. If the accelerator was oriented perpendicular to the sun, a particle moving at this speed would experience sizable length ...
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Why does the De Broglie Wavelength influence the scale in which a nuclear reaction occurs?

In high energy accelerator collisions, why does the De Broglie wavelength of the incident particle affect the type of interaction it has with the target nucleus? E.g. In 280 MeV proton, "direct ...
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How does a cyclotron release electromagnetic waves?

I am currently working on a project on fusion reactors and am researching the basics of them. During my research, I encountered "antenna" which produce ion and electron cyclotron frequencies to heat ...
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Relativistic mass and Electromagnetism in particle accelerators?

Dear Physics Stack Exchange, I've been rather troubled as of late on trying to see the problems or issues inherent in crank scientist or layman views on physics topics about special relativity. One ...
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4 votes
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Why did the RHIC luminosity decrease after 2010?

This physics today article about particle accelerator operation contains this figure, showing the evolution of peak luminosity over time for major proton-proton and proton-antiproton colliders. ...
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Accelerator terminology: betatron coupling, $\beta$-beat, chromatic coupling and beam tune

While reading papers on HEP, I often come across the following terms. Unfortunately, Google is not always helpful as it returns only papers related to the topic(s) and not something like a Wikipedia ...
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Are experiments being conducted towards the creation of micro black holes? [closed]

Apparently, there could be a way for our own particle colliders to create very transient black holes, if some things about the universe are true (as far as I understand, those have to do with the ...
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Accelerating a charged particle through more than one electrostatic field

If a charged particle is accelerated through a hole in a charged capacitor and makes a round trip back to the capacitor then the particle should come to a stop just before going through the capacitor ...
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What is the source of the electric field in a RF cavity that causes particle acceleration? [duplicate]

Charged particles are accelerated through a RF cavity: -Is the electric field accelerating the particles from the electromagnetic field itself? -Or, is the electric field accelerating the particles ...
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3 votes
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How does one create a polarized beam of particles?

I want to know how experimental physicists create spin-polarised beams of particles, say electrons, muons or quarks. My first guess is that one would polarise such a beam in a magnetic field. The two ...
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DC Electron beam acceleration with RF accelerator cavities without using buncher cavities

Can a low-emittance (as low as necessary) dc electron beam (about 100keV energy) be directly loaded to an long (long enough to self bunching and accelerating) RF accelerartor structure without using ...
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Bremsstrahlung in synchrotrons

In synchrotons electrons are accelerated by undulators or wigglers. However, I don't get how you produce Bremsstrahlung, because Bremsstrahlung is a 3-particle process: charged particles, ions and ...
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Why is the opening angle of synchrotron radiation less than $1/\gamma$?

I am currently studying free-electron laser which accelerate electrons and use undulators to create synchrotron radiation. In a variety of graphics and diagrams I see an opening angle of $\pm 1/\gamma$...
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How the relativistic mass gain prob is overcome in synchrotron by adjusting the frequency of electric field to accelerate particles to high KE?

Cyclotron cannot accelerate particles beyond certain KE due to relativistic mass gain. I am from Chemistry background.
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How would I go about calculating the energy input needed for a cyclotron reactor?

I'm trying to do some math regarding cyclotron reactors. I've figured out how to calculate the radius of a particle's motion in the cyclotron, a rough way to calculate energy output, but I have looked ...
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