1. How are electrons dispersed within the EELS magnet prism?
2. Which function is used to model background intensity in a spectrum?
3. Which function is used for the spectrum’s low-loss region (less than 100eV).
1.The existence and formation of electromagnetic pieces with a shaped shape results in the creation of a uniform magnetic field (denoted B), with an order of 0.01T.
This magnetic field produces electrons which follow a circular path that has a radius of R. The electrons will then spontaneously deflect at an angle normal to 900.
The force exerted on electrons by sideways is
F = B*e*v
e = Speed of Electron
v = charge
m = Mass of Electron
The resultant bending radius for electrons directly dependent on velocity, hence electron energy will equal;
This clearly shows that electrons can be bent and dispersed by the EELS magnet prism
2.Typically, the model can be determined by linear least-square using a single predefined region G.
G = background fit window
= sign intgergration windows
Ib = background intensity
Ik = signal intensity
Power law formulae are the most commonly used background model to determine the spectrum’s intensity
J( E) = A
A = Scaling constant
r = slope factor (that is often 2-6)
3.The EELS found in the low energy region of less than 100 ev, is known as valence energy lost spectroscopy.
Low loss is what determines’
Excitation of electrons in the valence band
A dielectric formulation can describe the EEL spectrum at the blow loss area as follows:
v = speed of incident region
na = Number of Atoms Per Unit Volume
E = The characteristic scattering angle (E/m0v2)
Im( = energy loss function
From the EEL spectrum, low-loss is used to calculate the complex dielectric functions 1 + 2.