# proton

1. ### Proton structure

Hi all. I'd personally consider the De Broglie wavelength λ=h/p, with p being the momentum of the electron beam. I get $$\lambda \simeq 0.6 \times 10^{-18} m$$ and since the radius of a quark is $\leq 10^{-19} m$, the proton structure can't be resolved. I'm quite sure there's something...
2. ### Kinetic Energy of Protons

So first I tried to use KE=1/2 x m x v^2 but then realised I didn’t have the velocity and I can’t figure out a way to obtain it. I then tried to work out the energy using a different equation, W= q x v but that left me with 1.28x10^-14 J which seemed too small. I also then have to calculate the...
3. ### Find the position of a proton in an E and B field

Hello all, I have a question with the helix path of proton in a magnetic field that I am a bit stuck on. Question: Equations: F = qv X B F = mv^2/r d=vt My Attempt: Think the graph drawn is good enough for questions (a). However, I am stuck on (b) and (c). Firstly I am not entirely sure...
4. ### A Photons per unit of Energy in Cherenkov radiation?

If I have a beam of protons that go into a block of water, how can I know how many photons will be produced along the beam path?. I'm assuming all the photons have the same energy. I know that the energy deposition will follow a Bragg Curve, and I think that energy deposition is probably...
5. ### I Rotating speed of a proton ion

I tried to calculted the rotating speed fro a proton from the clasical point of view by using its magnetic moment and the moment of a rotating sphere uniformly charged as example here: https://ocw.mit.edu/courses/physics/8-07-electromagnetism-ii-fall-2012/exams/MIT8_07F12_quizsol2.pdf It is said...
6. ### B How close does an electron get to a proton to be attracted

I couldn't fit the whole question, it should say "How close does an electron have to get to a proton to be attracted to it" And I know it can depend on the speed and direction they are traveling. Can we just pretend they are stationary for this answer please. By attracted I mean the electron...
7. ### I What does a proton look like?

If a proton is made of quarks and gluons, what exactly IS a proton? What would it look like if we could shrink down to it's size? Is it really nothing at all, in the same sense as the "solar system" isn't really a thing in itself, it's just a collection of planets and a sun.
8. ### An electron & a proton are each placed in an electric field

1. Homework Statement An electron and a proton are each placed at rest in an electric ﬁeld of 687 N/C. What is the velocity of the electron 56.5 ns after being released? Consider the direction parallel to the ﬁeld to be positive. The fundamental charge is 1.602×10−19 C, the mass of a proton is...
9. ### A Velocity Drifts of proton-muon gas

When do we use the equations of curvature drift ( ΔΒ⊥Β) V∇B= ±1/2u⊥rL (B x ∇B)/B2 and the general VF= c/q (F x B)/B2? For particles like muons and protons, do they need different equations to calculate a gas' drift velocity, when the gas is made of protons or muons instead of electrons? Am I...
10. ### I Why are all particles of the same type identical?

Why all particles of same type identical? All electrons are identical to each other, all protons are identical..etc. It is as if they are copy pasted from each other! For me this is one of the biggest mysteries ever, why we don't detect more massive or less massive electrons? Is it related...
11. ### 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...
12. ### Total Angular Momentum of an odd-parity shell-model state

1. Homework Statement A certain odd-parity shell-model state can hold up to a maximum of 4 nucleons. What are its values of J and L? What about an odd-parity shell-model state with a maximum of 6 nucleons? 2. Homework Equations Parity = (-1)L J = L+S Total angular momentum, J, is equal to...
13. ### B How many gluons on average are there in a proton at once?

A proton is made of quarks and gluons bound by the strong force in a confined system. Further, all protons are basically interchangeable parts for the purposes of this question. Each one is identical in all material respects. Scientists know a lot about gluon energy density in protons. We have...
14. ### I Specifically, why is the neutron heavier than the proton?

Proton is made of 2 up, 1 down quarks Neutron is made of 2 down, 1 up quarks The up and down quark have different masses, which account for some of the mass difference. I've also read that hadron masses depend upon the interactions/dynamics inside the particle, not just the quarks contained...
15. ### Estimate for the change in range for a proton

1. Homework Statement I've uploaded the question in the attached file. 2. Homework Equations R ∝ 1/p R ∝ M/z2 3. The Attempt at a Solution I don't understand what is in my lecture notes. What equations do I need to attempt this question? Thank you.
16. ### Is today's exam question unsolvable? - Proton Motion in a Magnetic Field

<Moderator's note: Moved from a technical forum and thus no template.> Hello all, Earlier today I had an electromagnetism exam, and it seems to me that this problem is unsolvable. There's just too little information given. A proton enters an uniform magnetic field. It's initial speed v is...
17. ### Trajectory of a proton as it moves between the plates

1. Homework Statement 2. Homework Equations What makes the shape circular/ parabolic? what determines the direction? 3. The Attempt at a Solution Because the furthermost plate is positive, the proton would be repelled towards the screen, so i or iii. How do I know the shape?
18. S

### B Explaination of beta + decay in layman language

QUESTION: I read in book that in beta + decay proton decays to neutron But i can't understand how it is possible if proton mass is less than neutron mass.I read on net but it says 'quarks' and 'd u p' things which i dont study about currently. Also why it only happen inside nucleus?What does...
19. ### Mass of Hydrogen needed to determine lifetime of proton

1. Homework Statement The current limit on the proton’s lifetime is determined by observing a large body of water for a long time and noticing that no one of the hydrogen nuclei in H2O have decayed. Assuming that the experiment making this measurement has been going on for 10 years, how many...
20. ### I Neutron/proton nucleon destruction by acceleration

A nucleon that consists entirely of two or more protons, would be accelerated evenly, as each proton would see the same force (barring any collisions or other extraneous events.) Each should experience the same force of repulsion or attraction that is causing them to accelerate, so they should...
21. ### Physics 12: electromagnetism problem -- Find the acceleration of the proton in a B-field

1. Homework Statement A proton is accelerated from rest at the positive plate of two charged parallel plates with a potential difference of 2000 v. After leaving the plates through a small hole in the negative plate, it enters a uniform magnetic field of 0.50 T in a direction perpendicular to...
22. ### I Antimatter in proton

Hi! I am asked to calculete the portion of antimatter present in protons. I am sayed that this portion is given by: r=(3R-1)/(3-R), where R is R=σ(antineutrino)/σ(neutrino). Another definition of r is r=∫x*Q'(x)dx/∫x*Q(x)dx, where Q(x) are partonic densities Q(x)=d(x)+u(x) (d is down quark and...
23. ### Speed of Protons

1. Homework Statement In a proton linear accelerator, protons are accelerated to have a kinetic energy of 530 MeV. What is the speed of these protons? (The rest mass of a proton is 1.67 × 10-27 kg.) 2. Homework Equations E0=m0c^2 E=E0/√1-(v^2)/(c^2) E = KE + E0 3. The Attempt at a Solution...
24. ### What fraction of its energy does accelerating proton shed?

1. Homework Statement If a proton with a kinetic energy of 6 MeV is traveling in a particle accelerator in a circular orbit of radius 0.75m, what fraction of its energy does it radiate per second? m = 1.67 * 10^-27 epsilon_0 = 8.854 * 10^-12 c = 3 * 10^8 2. Homework Equations dE/dt = (q^2...
25. ### Error: no plot because it would be empty, using mcnpx

Hello everyone! I would like to ask you if anyone can help me solving my Problem with mcnpx. I created a file with a watertank, a nozzle and a slit blend on the surface. I also inserted a protonbeam and would like to plot the dose and fluence for examplte with Moritz. But when I execute the...
26. ### Speed of the Proton

1. Homework Statement In the figure, a proton, mass 1.67×10^−27 kg, is projected horizontally midway between two parallel plates that are separated by 0.20cm, with an electrical field with magnitude 7.8×10^5N/C between the plates. If the plates are 5.40cm long, find the minimum speed of the...
27. ### I Has anyone ever determined at what rate quarks move?

I am wondering if anyone has determined by experiment or calculation at what rate or even better what frequency the quarks move around at inside a neutron and proton? Do neutrons or protons vibrate at a specific frequency.
28. ### Electron to Stationary Proton Collision

1. Homework Statement A 2 GeV electron is incident on proton (m_p * C^2 = 0.938 GeV) target at rest. Calculate the invariant mass of the electron-proton pair in the Center of Mass(CM) frame. Neglect the mass of electron which is much less than the proton mass. 2. Homework Equations M = [P1 +...
29. ### I How are protons, photons and quarks related electrically?

When protons, due to their electric charge, interact with photons are the quarks somehow also involved in this same electric interaction? After all, the quarks do have fractional electric charges. Thanks in advance.
30. ### I Electric charge

Is it right to say that 'modern physics has no deep explanation of the nature of charge' in electrons and protons?