1. University of Nebraska
A Statewide Outreach and Education Experiment in Nebraska
The Cosmic Ray Observatory Project
Dan Claes
University of Nebraska
APS-DPF JPS2006
Monday, October 30, 2006

2. was that the Silver Surfer could ride the shock wave of a super nova…

3. The Fantastic Four ® ©Marvel Comics
…and that 4 astronauts that lifted off in an inadequately shielded starship…

4. …were blasted by Cosmic Rays and mutated into the Fantastic Four.
Of course, ever since then they’ve been cool enough for me!
I grew up to be a high school instructor myself, spending 7 years as a physics and mathematics teacher before returning to graduate school for my PhD.

5. The Fantastic Four

6. CROP article in Lincoln Journal Star, 7 August 2003
Here’s how we make all of that come together at the University of Nebraska.
Our plan is to place on high school rooftops across the state, student-built and operated particle detectors.
As this local newspaper article summarizes, CROP is mobilizing high school teams across the state of Nebraska to participate in a state-wide study of correlated high energy air showers. Our plan is to place student-built and operated particle detectors on the roofs of all 314 high schools across the state.

7. The Chicago Air Shower Array
CROP is placing in the hands of high school teachers and students charged particle detectors inherited from the Chicago Air Shower Array, refurbished and operated by the students themselves.
CROP recycles retired detectors from the Chicago Air Shower Array
Located in the Utah Desert
1089 stations, 15m spacing
covering square km
each houses 4 scintillators w/tubes
1 high and 1 low voltage supply

8. Chicago Air Shower Array (CASA) site 2000 scintillator panels,
The CROP team at the
Chicago Air Shower Array
(CASA) site
2000 scintillator panels,
2000 PMTs, 500 low and HV
power supplies now at UNL
Through contacts at his former home institution at Michigan Greg brokered a deal in which we helped clean up the abandoned CASA site in exchange for whatever we could carry away.
Two removal trips (September 1999, May 2001) yielded over 2000 scintillator panels, 2000 PMTs, 500 low and h.v. power supplies
CASA detectors’ new home
at the University of Nebraska
U.S. Army Photo
September 30, 1999

9. The Cosmic Ray Observatory Project
A grid of cosmic ray research stations
expanding across the state
250
miles
The plan in Nebraska is to re-distribute these counters to a less geometrical but far more expansive grid, by placing them on the rooftops of Nebraska high schools, to conduct a study of correlated extensive air showers.
450 miles

10. co-funded by ESIE and EPP divisions • Co-PIs Greg Snow and Dan Claes
• $1.34 Million NSF grant,
co-funded by ESIE and EPP divisions
• Co-PIs Greg Snow and Dan Claes
• 26 Nebraska and 5 Colorado schools enlisted
trained in (2-4 week long) summer workshops
about 5 new schools each year
• Colorado program (SALTA) was a joint effort
by CROP, WALTA, ALTA
• External evaluation: CROP has accomplished
most of the educational & scientific goals listed
in the original proposal
• CROP also serves as excellent training for student
(undergrad, graduate) staff at UNL
NSF

11. CROP Workshops
In Nebraska the detectors and supporting electronics are refurbished and distributed through the 4-week Summer Workshops we run at UNL attended each year by 5-6 high school teams (of 1-2 teachers, bringing 1-4 students).

12. Oscilloscope
training

13. Tearing
the old
CASA
counters
apart

14. Scraping, sanding and polishing

15. Wrapping & light-tighting

16. Electronics
lessons

17. CROP data acquisition electronics card
Developed by Univ. Nebraska, Fermilab (Quarknet), Univ. Washington
Programmable
logic device
Time-to-digital
converters
To PC
serial port
GPS receiver
input
Four analog
PMT inputs
5 Volt
DC power
Event
counter
43 Mhz (24 nsec) clock interpolates
between 1 pps GPS ticks for trigger time
TDC’s give relative times of 4 inputs with
75 picosecond resolution
Discriminator
(adjustable
threshold)

18. User-friendly, LabView-based control and monitoring GUI
Event
counter
Elapsed
run
time
Two detectors
firing at the
same time
Data stream
for each
event

19. April 2001 participant meeting at UNL results and discussing
Marian High School
students presenting
results and discussing
cosmic rays with
Prof. Jim Cronin,
University of Chicago
A hallmark of CROP is a pair of 1-day all-day Saturday meetings held during the school year, where participating schools make presentations in a scientific conference-style setting. Jim Cronin was our guest at one Spring meeting, and when Marian high school made its report:

20. Statistical error bars shown
Barometric Pressure (mmHg)
727
747
4-Fold Coincidences / 2 hours
3000
4200
Marian High School’s Measurement
of Cosmic Ray Rate vs. Barometric Pressure
Statistical error bars shown
1.3% decrease per mmHg
On the variation of rates with barometric pressure he audibly gasped (he was sitting next to me and leaned over to say: “That’s exactly what WE found at CASA!”).

21. Mount Michael Benedictine “The Science Teacher”, November 2001
High School
“The Science Teacher”, November 2001
Students at Mount Michael High School made measurements of the diurnal variation, which resulted in a publication in The Science Teacher.

22. Ben Plowman, Lincoln High School
state finalist in the American Junior Academy of Sciences
invited to present at the Washington, DC, meeting (February 2005)
Rudy Resch and Kent Shirer presented a poster on their follow-up work
at the Intel International Science and Engineering Fair (Phoenix, May 2005)
and placed fourth in the physics category.

23. UNL Physics Department roof
Marian High School
March 8, 2002
Several schools are running
detectors on their roof.
UNL Physics Department roof
February 2002
Westside
High
Omaha
To give you more of an idea of the performance of these recycled counters:
For over a year we have been running a set of 4 on our own rooftop.
note the
theater
weights!

24. 1 mile Simultaneous data-taking at 3 sites
UNL Ferguson Hall
Lincoln High
Zoo School
1 mile
DAQ card discriminator thresholds set to obtain ~ 100Hz singles rates
At each school, require 3-fold coincidence of detectors
Two-fold inter-school coincidences (within 2-3 microseconds) in excess of
expected accidental rates have been observed! (but so far no 3-folds)

25. Summer 2005

26. Vanderbilt University Jason Keller University of Nebraska
Andrea Fuscher
Vanderbilt University
Jason Keller
University of Nebraska
Andy Kubik
Northwestern
University
Xiaoshu Xu
Master’s Degree in Statistics
University of Nebraska
Tracie Evans
Ralston Public Schools
Andy Warta
University
of Minnesota
Peter Jacobson
Tulane University
Katie Everett
University at Buffalo

27. Online help and tutorials available.
Cosmic Ray Observatory Project
Collecting Data with CROP DAQ Card Interface
Doing an Efficiency Scan
Disconnect the 4 signal cables from the DAQ card.
These are the cables that connect to your 4 detectors.
Open the CROP_DAQ LabVIEW Program.
3. Click on the "Efficiency" tab make sure
the Efficiency Scan button is ON(lit up). 4.  Click on the "Threshold Scan" tab make
sure the Threshold Scan button is OFF. 5. Click on the "Data Collection Settings" tab
and set the timer ON (green button lit up). 6.  Click on the "Data Acquisition" tab and
to begin run click on 
(upper left corner under the Edit menu).

28. On-Line Oscilloscope Cheat Sheets

29. Some Lessons Learned
• Big variation among our schools in independent activities.
Some real successes, some inactive sites
• Hardware/software delays create frustration and idleness
Close contact very important during academic year
• A scheme for replacing/training new students as classes
graduate is very important
• High school schedules are packed (full participation in
academic year Saturday meetings is difficult)
• Classroom integration, affect on curriculum not automatic.
Need to be tied directly to standards!
• Hard to recruit for long summer workshops
Our expansion phase (to ~100 schools) will be developed through
shorter remote workshops hosted by the regional offices of the
state’s 19 Educational Service Units.

30. Selected 120 mile radius (2 hr trips) arcs shown

31. Selected 120 mile radius (2 hr trips) arcs shown

32. Selected 120 mile radius (2 hr trips) arcs shown

33. If time allows…

34. SALTA: Snowmass Area Large Time-Coincidence Array
Empire
Aspen High School, Aspen, CO
Basalt High School, Basalt, CO
Roaring Fork Valley High School,
Carbondale, CO
Lake County High School,
Leadville, CO
The highest-elevation school in U.S.
-- 10,152 feet above sea level
Exactly 3 years ago…in July 2001 CROP and WALTA jointly sponsored a Rocky Mountain cousin involving 4 schools in the Roaring Fork Valley
…recently joined by Clear Creek High school, a very interested school in not-quite-so-nearby Empire, Colorado.
Clear Creek High School,
Empire, CO

35. SALTA Workshop, July 2001, Snowmass, CO
Making detectors light-tight
This publicly open 1-week workshop ran in conjunction with the Snowmass meeting…where some of you may in fact have watched some of its activities.
Polishing scintillator
edges outside
Conference Center
mass
phototube
gluing

36. Henderson Mine Visit Chip deWolfe
Dec 4, 2003
hosted by
Chip deWolfe
Hans-Gerd Berns
University of Washington
Dan Claes
University of Nebraska
Marc Whitley
Aspen High School
Diana Kruis
Basalt High School
Michelle Ernzen
Lake County School
Laura French
Roaring Fork Valley
Nancy Spletzer
Clear Creek High School
Claes’ began regular communication with the SALTA schools, and organized last week’s 1st meeting of them all in 2 and ½ years at a special orientation to and tour of the Henderson Mine hosted by Chip deWolfe.
Scouted 3 possible
locations
between depths of
2800  3900 ft
110 power available

37. Detectors were configured into muon telescopes
telescoped pair with coincidence requirement against noise
sandwiching a ¼ inch lead sheet
Detectors
moved at
2-3 week
intervals
since dust posed
a problem for a PC
we housed a
low-power serial
digital data logger
alongside
the DAQcard
2 modules
taken
down into
the mine
A portable stand held each muon telescope.
Desktop
Base Station
An ~identical
pair of modules
ran in a fixed
location
(surface office)
to establish
our baseline

38. SALTA’s Henderson Project was launched September 29, 2004

39. Clear Creek students set up the satellite modules
Basalt students move the
detectors to the next location

40. Some preliminary observations
Data collected between Sept 29 – Dec 8, 2004
monitored 4 locations between depths of ft
Some preliminary observations
Rates at Henderson surface base station (10,337 ft above sea level)
= 2.5rates at Lincoln, NE (elevation: 1189 ft)
Raw rates in muon telescopes seen to drop from
10 Hz (surface rate) → 1.5 Hz → 0.5 Hz → 0.3 Hz

41. …learning about the statistical nature of random events
Successive teams of high school students have been analyzing the data
identifying stable
data run periods
bad data channels
Channel 0,1
coincidences
Channel 2,3
coincidences
…learning about the statistical
nature of random events
…and calculate accidental coincidence rates and statistical error