Shape of charged beam due to deviation in angle/velocity

[Fu-Kwun Hwang]

A charge q with velocity v enter into a region with perpendular to magnetic field B, will move in a circular orbit.
The trajectory of the beam will spread out if the bean is deviated with a small angle (dca in the simulation) or with small deviation in velocity (dv)

The angle = dca * (random() -0.5); // where random() give random number between 0-1
The velocity v=V+ dv* (random() -0.5);

The trjjectory for all different possible paths are shown in the following simulation.

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.chargeinBvdc_pkg.chargeinBvdcApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_chargeinBvdc.jar' name='chargeinBvdc5409' id='chargeinBvdc5409' width='412' height='500' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=5409' target='smfejs'>Run simulation</a>

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.

Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

[macfamous]

may we change for the point random .. it means become positive ..

[Fu-Kwun Hwang]

The above simulation assume the beam enter into the magnetic field vertically (but there is a small angle deviation).
I think what you mean is that the beam might enter into the field with a angle.
The code has been updated, so that you can change the incident angle with slider c, or drag the red arrow to change it direction directly.

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.chargeinBvdc_pkg.chargeinBvdcApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_chargeinBvdc.jar' name='chargeinBvdc5453' id='chargeinBvdc5453' width='491' height='576' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=5453' target='smfejs'>Run simulation</a>

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.

Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!