User:David E. Sosa/Notebook/2008/09/24

Project name

Notes for the 2nd part of the speed of light lab

A brief comment about last lab We spent the whole laboratory trying to see up the experiment. With the help of Dr. Koch and Aram we were able to understand what was wrong with our set up. So we fixed everything, but due lack of time we were only able to make 1 measurment. This part #2 of the laboratory should be all about making measurments ad nauseum so we can get the best possible data.

Things to do before the lab

Check the past lab notebooks, copy some measurments and compare with ours.

Don't forget the camera¡

Some data to compare with our own

Taken from http://openwetware.org/wiki/Physics307L_F07:People/Smith/Notebook/4
I will be using this data to compare our results since Dr. Koch sugested that Jesse Smith's data was one of the best.

Laboratory

Round of measurment 0 nsecond delay. PMT Reference Voltage: -800mV +/-

=1st Measurment
2) 150 cm   2.56 V
3) 140 cm   3.48 V
3) 120 cm   3.68 V
4) 100 cm   3.36 V
5) 80 cm    3.12 V
6) 60 cm    2.69 V 
7) 50 cm    2.12 V

=2nd Measurment.=
V= 1908 Range 50 ns
PMT Reference value -1.12V
1) 60 cm  2.10 pm. 0.04 V  
2) 50 cm  2.04 pm. 0.04 V
3) 40 cm  2.02 pm. 0.04 V
4) 30 cm  Same as above V
5) 20 cm  1.95 pm  0.04 V
6) 10 cm  1.84 pm  0.04 V

=3rd Measurment=
V= 1908 V Range 50 ns
PMT Reference value : 850 mV
1) 160 cm  3.00 pm 0.04
2) 150 cm  2.94 pm 0.04
3) 140 cm  2.90 pm 0.04
4) 130 cm  2.87 pm 0.04
5) 120 cm  2.82 pm 0.04
6) 110 cm  2.78 pm 0.04
7) 100 cm  2.70 pm .04
8) 90 cm   2.66 pm
9) 80 cm   2.54 pm 
10) 70 cm  2.52
11) 60 cm  2.46
12) 50     2.38

We are gonna try some measurments with time delay.

1900 V 2 ns time delay

=4th Measurment=

PMT= 1.2 V

1)130 cm   2.38 pm .04
2)120 cm   2.34 pm .04
3)110 cm   2.22 pm .04
4)100 cm   2.14 pm .04
5)80 cm    2.04 pm .04

5th measurment 1) 100 cm 2.66 pm .04 2)

( We are having trouble setting up the oscilloscope. It was already ready, but we moved something and messed it up. Aram and us are trying to fix it know.)