150 likes | 161 Views
Learn how to calculate the momentum of an electron and measure the radius of curvature in a magnetic field using the Lorentz law. This tutorial provides step-by-step instructions and helpful diagrams.
E N D
How to calculate the momentum of an electron ? Measuring the radius of curvature in a magnetic field … Dora Wagner & Miguel Vieira HST 2001
If electrons are entering a magnetic field, they are forced to go on a circle. They go on spirals if they are also loosing energy Dora Wagner & Miguel Vieira HST 2001
The Lorentz-law helps to describe this behaviour : Dora Wagner & Miguel Vieira HST 2001
goes into the page ! Dora Wagner & Miguel Vieira HST 2001
The Lorentz-force is the centripetal force, which pulls the electrons to the centre : Dora Wagner & Miguel Vieira HST 2001
Look at this sketch……click it ! Dora Wagner & Miguel Vieira HST 2001
How to measure the radius ? Dora Wagner & Miguel Vieira HST 2001
r = ? If we know the radius r … Dora Wagner & Miguel Vieira HST 2001
B = ? … and if we know the strength of the magnetic field B… Dora Wagner & Miguel Vieira HST 2001
… we are able to calculate the momentum : Dora Wagner & Miguel Vieira HST 2001
Try it ! What to measure, what to know Scale 1 : 6.4 For more information click here Dora Wagner & Miguel Vieira HST 2001
In the Fermilab where this picture was taken, the magnetic field was : B = 3 Tesla The charge of the observed electron is : e = 1.6x10-19 Coulomb Dora Wagner & Miguel Vieira HST 2001
Are you able to use the Pythagoras theorem to calculate the radius r from L and D ? BACK Dora Wagner & Miguel Vieira HST 2001
A photon traveled between the two marked points. The traveled distance was, in the real experiment, 11.5 cm! If you want to know more,click-me Dora Wagner & Miguel Vieira HST 2001