Register to reply 
Magnetic dipole interactionby darkdave
Tags: magnetic dipole 
Share this thread: 
#1
Feb813, 01:03 PM

P: 21

I am simulating protons and electrons in a simulator that runs 1 femto seconds per second up to 1 second per second. So it can accurately show the passage of charge particles through space with data being updated on their displacement, velocity and acceleration.
However I am now adding in rotational data. This means that I need to simulate angular momentum and torque. How do I do this? For the electron do I have to calculate the torque at the classical electron radius at each pole due to magnetic interaction with other charged particle poles? 


#2
Feb813, 05:26 PM

Mentor
P: 12,081

In a classical simulation, particles cannot rotate. If you want "rotating" particles, you need quantum mechanics  and if spin is relevant, I would expect that everything else should use quantum mechanics as well.



#3
Feb813, 11:56 PM

P: 21

I am aware of the quantum complication but at the same time i can still create a bhor model intepretation since i know the angular momentum of the particle and its mass and classical radius. I just need to know how to simulate the particles changing orientation due to torque caused by external magnetic fields. Wether i choose to show particles spinning or not is irrelevant to what im asking since all i should be concerned about is the angular momentum of the particle.



#4
Feb913, 04:32 AM

Mentor
P: 12,081

Magnetic dipole interaction
The Bohr model works reasonably well for hydrogenlike atoms without spin, and nothing else, as far as I know.



#5
Feb913, 04:38 AM

P: 21

What is the vector B representing in that formula?



#6
Feb913, 04:42 AM

P: 21

ok i looked up that formula Force = charge velocity cross product magnetic field. The vector representing Magnetic field does it point to the center of the particle that acts like a magnet? For example is B pointing to the center of an electron if we are modeling 2 electrons that are interacting not just electrically but magnetically as well due to each of them having a magnetic field due to their intrinsic angular momentum



#7
Feb913, 04:43 AM

P: 21

Also what if the velocity of the particle is ZERO? Isnt the current orientation more relevant here?



#8
Feb913, 04:46 AM

P: 21

so think about it this way, we have 2 electrons each with a north and south magnetic pole and i want to simulate each electron turning its North Poles toward the other electron's South Pole. And each like poles repelling each other. So basicly i need to know torque.



#9
Feb913, 05:26 AM

Mentor
P: 12,081

Don't forget the electric part, it will be retarded as well. 


#10
Feb913, 05:29 AM

P: 21

What about this article? Sounds to me electrons have a magnetic field of their own.
http://en.wikipedia.org/wiki/Electro..._dipole_moment Also are you saying that an electron HAS NO ORIENTATION? 


#11
Feb913, 05:36 AM

Mentor
P: 12,081

Electrons are pointlike. What is the orientation of a point? 


#12
Feb913, 06:18 AM

P: 21

What I want to do is simulate electrons behaviour much like how real magnets behave when they are in close proximity. Their poles should point toward or away from other particle's dipoles. 


#13
Feb913, 06:50 AM

P: 21

The electron is a charged particle of charge (−e), where e is the elementary charge. Its angular momentum comes from two types of rotation: spin and orbital motion. From classical electrodynamics, a rotating electrically charged body creates a magnetic dipole with magnetic poles of equal magnitude but opposite polarity. This analogy holds as an electron indeed behaves like a tiny bar magnet. One consequence is that an external magnetic field exerts a torque on the electron magnetic moment depending on its orientation with respect to the field. 


#14
Feb913, 11:18 AM

Mentor
P: 12,081

A magnetic dipole is not something with a north and a southpole. The dipole has an orientation, but that can be a superposition of multiple possible orientations, and the strength of the dipole, measured in an arbitrary direction, is always a fixed number (for electrons) and just the sign is variable. There is no way to model this classically.



#15
Feb913, 12:20 PM

P: 21

so what do you suggest is the best way to simulate electrons in as much classical way as possible?
I mean I know they dont have "spin": in the classic sense, but I can still make them spin based on known facts for example: the classical radius of the electron, the known mass and the known angular momentum. This way they behave in a way that is not true to reality but its still based on real data so intuitively it has some hidden truth. What could I do for magnetic fields of the electron to do something similar to what i just proposed? 


#16
Feb913, 01:59 PM

Mentor
P: 12,081




#17
Feb913, 02:10 PM

P: 21

can you propose a setup?
So far I know I want to show the electron spinning based on the available data of known intrinsic angular momentum, mass and classical electron radius. Can you use that as a setup? And fill in any blanks for me at your discretion. I basicly want to show the particle changing orientation in real time in reaction to a neighboring particle's magnetic influence. If it cannot be continuus then make compromises. I can make the particle perform discrete changes in orientation if need be. BUT I NEED A MODEL ANYKIND OF MODEL ASAP!! :) 


#18
Feb913, 03:00 PM

Mentor
P: 12,081

I doubt that the results will be good, but maybe you can add dipoledipole interactions with the electron magnetic moment in a classical way. But if it does not influence anything, where is the point? 


Register to reply 
Related Discussions  
Magnetic dipole interaction  Classical Physics  12  
Why is there no constant magnetic dipoledipole interaction?  Quantum Physics  4  
DipoleInduced Dipole Interaction  Advanced Physics Homework  6  
Nuclear magnetic resonance dipole dipole interaction  Quantum Physics  0  
Derivation of dipoledipole interaction energy  Advanced Physics Homework  2 