- #1
UrbanXrisis
- 1,196
- 1
I am asked to construct a double-slit experiment for 5eV electrons. The first minimum of the diffraction pattern needs to occur at 5 degrees, what must the separation of slits be?
I'm guessing that I should use Bragg's law but I don't know how to calcualte a minumum because bragg's law is for maximums.
[tex]\lambda=\frac{1240eVnm}{5eV}[/tex]
[tex]n \lambda=2dsin \theta[/tex]
[tex]1x240nm=2dsin5[/tex]
i would solve for d but wouldn't that be a maximum?
Also, I am asked to determin how far the slits have to be from the detector plan if the first minima on each side of the central maximum are separated by 1 cm.
we know that theta is 5 and the height is 1 cm, so... using 1cm/theta(5)=11.4 cm? that doesn't seem right to me.
any ideas as to what i am doing wrong?
I'm guessing that I should use Bragg's law but I don't know how to calcualte a minumum because bragg's law is for maximums.
[tex]\lambda=\frac{1240eVnm}{5eV}[/tex]
[tex]n \lambda=2dsin \theta[/tex]
[tex]1x240nm=2dsin5[/tex]
i would solve for d but wouldn't that be a maximum?
Also, I am asked to determin how far the slits have to be from the detector plan if the first minima on each side of the central maximum are separated by 1 cm.
we know that theta is 5 and the height is 1 cm, so... using 1cm/theta(5)=11.4 cm? that doesn't seem right to me.
any ideas as to what i am doing wrong?