Table des Matières
Publicité
Les langues disponibles
Les langues disponibles
At the ideal setting, slight flickering of the LED may
be observed. If the LED lights up brightly, the signal
is overloaded.
•
Note down the resonance voltage of the coil U
and the corresponding resonant frequency ν
(see Fig. 6).
•
If an oscilloscope is used the resonance voltage
can be read directly from the scope screen.
•
If 3B NETlog™ is being used, exit oscilloscope
mode and save the results. TH table of meas-
urements displayed can be displayed graphically
by clicking the appropriate button and the peak
can then be marked by means of the cursor. The
resonance voltage for the coil U
played.
•
Repeat the measurement for various frequencies
(in 5 MHz-steps).
R
R
is then dis-
R
Fig. 5 ESR experiment set-up using an oscilloscope
3
3.5 Evaluation
•
Calculate the magnetic field according to the
following equation:
mT
=
⋅
B
. 3
47
U
R
R
V
•
Plot a graph of magnetic field against frequency.
(see Fig. 8)
The relationship between the resonant frequency ν
and the magnetic field at resonance B
μ
ν
⋅
⋅
B
=
g
B
R
R
h
where
J
−
μ
=
⋅
24
. 9
28
10
B
T
−
=
⋅
34
h
. 6
626
10
Js
For electrons in free space the Landé factor g = 2.002
R
is as follows:
R
Publicité
Table des Matières
