- #1
peasqueeze
- 7
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So I am constructing an analogy between the self replicating fracturing effect on thin films and the path of a charged particle. (Qualitatively, several cracks have similar shapes to charged particle motion) I won't go into the details of the fracture mechanics, so I will only use E+M nomenclature.
My problem: Start with a parameterized path function, s, of a charged particle from which the velocity and acceleration functions can be easily derived. (a and R are constants)
$$\vec{s} = ( tcos(at) , tsin(at),(x^{2} + y^{2}) R )$$
I want to use this in a modified Lorentz Force equation where the mass-charge ratio is set to one (m/q=1)In the equation, I ultimately want to find a way to solve for all x, y, z components of E and B without resorting to Maxwell's equations.
$$ dv/dt = E + v × B $$
Current attempt: In order to reduce the amount of unknowns from 6 to 3, (i.e. from Ex, Ey, Ez, Bx, By, Bz to just Bx, By, Bz) I thought I can use the relation between kinetic energy and the electric field. I am not sure if this is the right thing to do, so feel free to suggest a different method for minimizing unknowns. I used the following relation for this (m/q=1 again):
$$Work = qEs = \frac{1}{2}mv^{2} $$
So now s, v, dv/dt, and each component of E is known thus leaving the components of B left to be solved. The following vector equation is the result of taking the cross product:
$$(a_{x},a_y,a_z )= (E_x,E_y,E_z)+(v_yB_z-v_zB_y,v_zB_x-v_xB_z, v_xB_y-v_yB_x)$$
I think this then simplifies to:
$$
\begin{pmatrix}
0& -v_{z} &v_{y} \\
v_{z}&0 &-v_{x} \\
-v_{y}& v_{x}& 0
\end{pmatrix}\begin{pmatrix}
B_{x}\\
B_{y}\\
B_{z}
\end{pmatrix} =\begin{pmatrix}
a_{x}-E_{x}\\a_{y}-E_{y}
\\ a_{z}-E_{z}
\end{pmatrix}
$$
Which doesn't seem to have a solution. What identities can I implement to yield solutions for this equation? Do I need to set one of the B components to 0? Is my equation for E useful in this case? Can I solve for Ex, Ey, Ez, Bx, By, Bz numerically- what numerical method would be useful?
tldr: I just want to know how to take a particle path and derive the electric and magnetic field components
Feel free to ask any questions for clarification!
My problem: Start with a parameterized path function, s, of a charged particle from which the velocity and acceleration functions can be easily derived. (a and R are constants)
$$\vec{s} = ( tcos(at) , tsin(at),(x^{2} + y^{2}) R )$$
I want to use this in a modified Lorentz Force equation where the mass-charge ratio is set to one (m/q=1)In the equation, I ultimately want to find a way to solve for all x, y, z components of E and B without resorting to Maxwell's equations.
$$ dv/dt = E + v × B $$
Current attempt: In order to reduce the amount of unknowns from 6 to 3, (i.e. from Ex, Ey, Ez, Bx, By, Bz to just Bx, By, Bz) I thought I can use the relation between kinetic energy and the electric field. I am not sure if this is the right thing to do, so feel free to suggest a different method for minimizing unknowns. I used the following relation for this (m/q=1 again):
$$Work = qEs = \frac{1}{2}mv^{2} $$
So now s, v, dv/dt, and each component of E is known thus leaving the components of B left to be solved. The following vector equation is the result of taking the cross product:
$$(a_{x},a_y,a_z )= (E_x,E_y,E_z)+(v_yB_z-v_zB_y,v_zB_x-v_xB_z, v_xB_y-v_yB_x)$$
I think this then simplifies to:
$$
\begin{pmatrix}
0& -v_{z} &v_{y} \\
v_{z}&0 &-v_{x} \\
-v_{y}& v_{x}& 0
\end{pmatrix}\begin{pmatrix}
B_{x}\\
B_{y}\\
B_{z}
\end{pmatrix} =\begin{pmatrix}
a_{x}-E_{x}\\a_{y}-E_{y}
\\ a_{z}-E_{z}
\end{pmatrix}
$$
tldr: I just want to know how to take a particle path and derive the electric and magnetic field components
Feel free to ask any questions for clarification!