Physics307L F09:People/Le/neon

Excitation of Neon

Purpose/Procedure

The purpose of this lab is to discover the quantized excitations of neon gas. To discover this, we scatter electrons off the neon atoms and see what energy of the electrons excites the atoms to their next level.

For more details see my lab book entry

Data

Graphs of accelerating voltage versus the current in the probe

http://openwetware.org/images/1/14/Neongraph3.JPG http://openwetware.org/images/3/31/Neongraph4.JPG

Results

Peaks found at voltages:16.25, 16.75, 18.25, 20.50

According to a paper included in last year's lab manual (see page 91), the resonance voltages for Ne are: 16.7, 18.65, 19.75, 20.10. Our values are very very close to these reported values.

For a quantitative look at the success of this experiment, let us compare the 2 values. (Note: we have values that the paper did not report, and vice versa. I will only compare those that match)

[math]\displaystyle{ %error= \frac{|Actual-Experimental|}{|Actual|}x100 }[/math]

[math]\displaystyle{ %error= \frac{|16.7-16.75|}{|16.7|}x100 }[/math]

[math]\displaystyle{ %error=.3 }[/math]

[math]\displaystyle{ %error= \frac{|19.75-18.25|}{|19.75|}x100 }[/math]

[math]\displaystyle{ %error=7.59 }[/math]

[math]\displaystyle{ %error= \frac{|20.1-20.5|}{|20.1|}x100 }[/math]

[math]\displaystyle{ %error=1.9 }[/math]

now taking the average of our error, Average Error= 3.26%

Errors

• The biggest source of error is the sheer sensitivity of the ammeter. Moving around the apparatus or talking near it changed the readings from the ammeter.
• The need to zero the meter could cause errors. If the zero was not set properly, or for some reason the zero shifted during measurements, it would skew our numbers

Final Thoughts

The experiment went very well despite the sensitivity to outside actions and other difficulties in taking measurements.

Possible Fixes

• If are able to isolate the experiment from any outside noise or movement we can avoid slight deviations
• If we were to take finer iterations in the measurements, the numbers may be more exact.
• Have a system that auto zeroed