QUARKNET 2011
SESSION 1
1
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Abstract
 Week One
 Hardware
 Performance
 Plateauing
 Flux
 Shower
 Lifetime
Purpose, Research Question,
Hypothesis
Experimental Design and
Procedure
 Personnel
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Rana
Monique
Data
Results
Errors
Conclusion
2
Abstract
(Week One)
Hardware
1. Counters
2.
QuarkNet DAQ board
3.
5 VDC adapter
4.
GPS receiver
5.
GPS extension cable
6.
RS-232 cable
7.
RS-232 to USB
adapter
8.
Lemo signal cables
9.
Daisy-chained power
cables
3
Counters
4
Detector #2
5
We placed detectors 0 and 1 together, one on top of the other.
The detectors were connected to HyperTerminal (computer program)
which read their information every minute.
Since we were working with the 5000 Series, we had to manually reset
the counter every minute, ON the minute, and input the data into a
spreadsheet.
We set the voltage of both detectors to 0.60 V; increasing by 0.02 V
every minute until we were able to clearly identify a voltage where
the paddle(s) plateaued.
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Combined Data for Step 1
3500
Counts per Minute
3000
2500
S0
2000
S1
1500
Coincidence
1000
500
0
0.6
0.62
0.64
0.66
0.68
0.7
0.72
0.74
0.76
0.78
0.8
0.82
0.84
Counter 1 PMT Voltage (Volts)
Our data yielded a plot which made it apparent that our
plateau range for Channel 1 was between 0.78 and 0.8 V.
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A performance study
should look something
like a normal curve with
preferably one peak.
Our graph has
its highest peak
coming from
channel 1.
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 We collected data for five
days and used that data to
do a flux study.
 A flux study studies the
consistency of the events
over time.
 A more stable graph shows
the consistency of the data.
 The graph to the right
shows the performance
study for the data
collected.
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•
•
We ran another data collection session over night in order to
conduct a shower study.
The paddles were un-stacked so that the coincidence of all 4 paddles
would be measured, which would depict a cosmic ray shower.
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Lifetime Study
We stacked our
detectors and let them
run overnight.
The graph to the right
shows the lifetime as
detected by our
counters.
The accepted lifetime of
a muon is 2.2
microseconds. We just
about hit that nail on the
head!
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Purpose
To determine whether or not lead sheets could affect the flux of
muons.
Research Question
Can one millimeter thick sheets of lead affect the flow of muons
to Detector #2?
Hypothesis
Muons will be able to pass through the first three detectors
without a problem, but will not be able to penetrate the sheets
in order to hit the fourth detector.
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Technical
Responsible for…
•Setting up all HyperTerminals
•Saving and uploading Data
•Capturing Data
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Physical
Responsible for…
• Adjusting Voltage
• Checking Counters
• Keeping track of sheet
count
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Detector 0
Detector 3
Detector 1
Detector 2
Detector 0 is 0.46m
above Detector 3 which
is 0.25m above Detector
1 which is 1.01m above
Detector 2.
SHEETS OF
LEAD!!
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After the paddles were stacked, we ran
HyperTerminal and told it to only count hits
with four-fold coincidence (command: WC
00 3F).
We ran HyperTerminal with the same command
(WC 00 3F) seven times, once without any lead
sheets and the other six times with lead sheets
(adding ten each time).
Since we are QuarkNet students, our day
is planned for us; therefore, we weren’t
able to stop each count at exactly one
hour like we had intended.
Not being able to stop it exactly when we
wanted to wasn’t a problem, though. We
simply let HyperTerminal do its job and then
divided the number of four-fold hits by the
amount of time it had been running.
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Data
Detector 2 average count after one hour with zero sheets:
Detector 2 average count after one hour with ten sheets:
Detector 2 average count after one hour with twenty sheets:
Detector 2 average count after one hour with thirty sheets:
Detector 2 average count after one hour with forty sheets:
Detector 2 average count after one hour with fifty sheets:
Detector 2 average count after one hour with sixty sheets:
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Data- Bar
7
6
5
Hits
4
Sheets
3
2
1
0
10
20
30
40
50
60
70
80
90
100
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Data- Line
Lead Sheet Experiment
90
86
82
80
74.4
73.2
72.5
70
64
63.6
60
Hits/Lead Sheet
Hits
50
40
30
20
10
0
0
5
10
15
20
25
30
35
40
45
50
55
60
65
Lead Sheets
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Our data shows that the lead sheets did decrease the
number of hits that were detected on Detector 2, but
not as much as we had hoped. We believe that the lead
prevented the slower moving/lower energy muons
from passing through and hitting Detector 2. We
believe that the reason our numbers didn't continue to
go down was because we had enough lead to stop the
slower moving muons, but the other simply had too
much energy. We concluded that more lead would be
needed in order to continue expending the energy of
muons so that they don't reach Detector 2.
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During our experiment, we had
some trouble with our
computer and the program
(HyperTerminal) that we were
using. The computer actually
stopped collecting the data for
some reason. We knew that we
had gotten significantly more
hits than the computer had
reported because the DAQ’s
number was much, much
larger. So, we had to figure out
what the problem was (a cable
had come unplugged) and,
once we did, we had to run that
portion of the experiment over
again.
The DAQ board is probably
the most important piece of
hardware in the entire
experiment since that’s what
talks to the computer and
puts the data in a form that
we can read and use, so
when we found not one, but
TWO cords that were
making the board reset
itself, we were worried. We
ended up having to tape the
cords down so they wouldn’t
move and reset the board. It
was very inconvenient. The
shortages were our biggest
issue; they cost us a lot of
time, but WE PREVAILED!!
Near the end of our
experiment, one of
the worst possible
things happened…
eLab stopped
working. Luckily, it
was only down for a
couple of hours,
though, so it didn’t
hurt us too much.
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When we started our experiments, one thing we didn’t expect was for our
equipment to malfunction, especially not as much as it did.
The only errors that could have affected the results of our experiment is if one
(or more) or our cables connecting our detectors shorted out and stopped
working during the time we were collecting data.
Our counts for Detector 2 seem to be consistent throughout the entire
experiment, though, so we don’t have any reason to believe that any of our
counters or cables had shortages during the running of our experiment.
We had a lot of “noise” getting through to Detector 2 before we started our
experiment. So much that we had to take it apart and re-seal it. We seemed to
have fixed the problem at the time, but since we sealed Detector 2 correctly the
first time (or so we thought) maybe it’s possible that noise may have gotten in
during our experiment.
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
What did we learn?
› We found that the lead sheets did have some affect
on the energy of the muon. The general correlation
for the first thirty sheets seemed to be that the more
lead that was added, the less hits were detected on
the bottom detector. We concluded that number of
muons that hit is directly proportional to the number
of lead sheets for the first thirty sheets.

What is the next step for our experiment?
› Continue adding sheets of lead and see how many
(if it’s possible) it will take to completely stop the flow
of muons to Detector 2.
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