plot Bethe-Bloch equation

Dear people,

For a project I have to plot the Bethe-Bloch equation. That is this equation: dedx = (-K*z^2*Z)/(A*beta2)*(0.5*log((2*me*1*10^9*beta2.*gamma2.*Tmax)/I^2)-beta2);

Every time i want to run the program it says the matrix dimension must agree. i do not know what i am doing wrong. I am trying this since the morning and I would like to move on. The only thing that chances is the eng. This has to run from 0 to 0.5 GeV.

clc; clear; z = 1; re = 2.817*10^-15; Z = 29; A = 63.546; Na = 6.022*10^23; mp = 0.93827231; %GeV eng = 0.001:0.001:0.5; %GeV gamma = (eng + mp)/mp; gamma2 = gamma.*gamma; beta = (1.0 - (1.0/(gamma2)')).^0.5; beta2 = beta.*beta; me = 0.51*10^-3; c = 3*10^8; I = 10*Z; K = 4*pi*Na*re^2*me*c^2;

Tmax = (2.0 * me*1e9*beta2'*gamma2)/(1.0 + (2.0*gamma*(me/mp) + (me/mp)^2)); Tmax = Tmax';

dedx = (-K*z^2*Z)/(A*beta2)*(0.5*log((2*me*1*10^9*beta2.*gamma2.*Tmax)/I^2)-beta2);

figure; plot(eng,dedx);

[Honglei Chen]

Please format your code

http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

[Jeroen]

clc;

clear;

z = 1;

re = 2.817*10^-15;

Z = 29; A = 63.546;

Na = 6.022*10^23;

mp = 0.93827231; %GeV

eng = 0.001:0.001:0.5; %GeV

gamma = (eng + mp)/mp;

gamma2 = gamma.*gamma;

beta = (1.0 - (1.0/(gamma2)')).^0.5;

beta2 = beta.*beta;

me = 0.51*10^-3;

c = 3*10^8;

I = 10*Z;

K = 4*pi*Na*re^2*me*c^2;

Tmax = (2.0 * me*1e9*beta2'*gamma2)/(1.0 + (2.0*gamma*(me/mp) + (me/mp)^2));

Tmax = Tmax';

dedx = (-K*z^2*Z)/(A*beta2)*(0.5*log((2*me*1*10^9*beta2.*gamma2.*Tmax)/I^2)-beta2);

figure;

plot(eng,dedx);

[Kunal Kumar]

Jeroen, I am having this same problem. Can you help me with the code. I tried running your code but it shows error. Can you share the code that ran on MATLAB.

Answer 1

[Grzegorz Knor]

Use .* (the element-by-element product) operator for array multiplication.

[Jeroen]

Okay thank you but that does not solve my problem. It keeps on saying that matrix dimensions must agree.

[Grzegorz Knor]

The same for division: ./

I've checked, and it works.

[Jeroen]

Okay thank you. It works now!