Subject: Re: Regarding your Cyclotron Applet. Date: Wed, 6 Jan 1999 14:32:25 +0000 (WET) From: Joao Manuel Henriques <jmh@camoes.rnl.ist.utl.pt> To: Fu-Kwun Hwang <hwang@phy03.phy.ntnu.edu.tw> Hi Again. First let me apologise for not responding sooner, but I was on vacation. Second, I would like to thank you for having sent the Source Code, it really helped alot... Now it is my turn to help you out (if U want to), I made another program that simulated: ' Attwood's Machine', since you dont have it on the list I could send you a copy of it ..(it is in C though...) Let my know if you want it or not...BTW it also uses RK4, but it looks diferent from your routine.... Anyway thank you very much. On Fri, 18 Dec 1998, Fu-Kwun Hwang wrote: > > > Joao Manuel Henriques wrote: > > > Hi. > > I am a student of the University of Lisbon and I was a assigned a task to > > simulate the cyclotron. > > It has been really hard to make something that actually resembled a > > cyclotron, but i still cant make the electron spin according to the > > frequency of the Voltage. > > Can you please help me out? > > > > Here is what I need to know: > > -I calculated a formula that calculates Theta, but the center of the > > circular movement is constant. In other words the Ray of the circunference > > increases, but the center doesnt change like it should. > > Can you tell me the formula to theta? > > > > This is not the way I did it. There is a better way to do it: > If you know the velocity V and force (F=qVXB) at time t, > you will be able to calculate velocity at t+dt; > If you know the position and velocity of a particle at time t, > you will be able to calculate next position at time t+dt. > Repeat the above loop, you will know the next position and velocity at next > moment t+dt; > > > > > > There is something else I want to ask. > > Is there a possibility of you sending me the source code? > > I know this is an unusual request, but it would really make me understand > > how the program really works. My source code is so complex that not even I > > can understand it, and above all it doesnt simulate the cyclotron right. > > I would be very gratefull if you could send it. I promise I wouldn't > > change the code and say that the program is mine. All I need to know is > > how you did it. > > > > Well, please e-mail me back with a response, preferably one with the > > reply i want to get. > > > > Thank you for your attention. > > > > > > Joao Henriques > > http://camoes.rnl.ist.utl.pt/~jmh > > The source code is attached with this e-mail. But you will need to know about > the > Runge-Kutta method to understand the rk4 class. >