1. Nebraska’s Statewide Outreach and Education Experiment The Cosmic Ray Observatory Project Dan Claes University of Nebraska-Lincoln Washington Area Large Time-coincidence Array SALTA Schools and the Henderson Mine Project Thursday, October 14, 2004

2. CROP article in Lincoln Journal Star, 7 August 2003

3. The Chicago Air Shower Array Located in the Utah Desert 1089 stations, 15m spacing covering 0.23 square km each houses 4 scintillators w/tubes 1 high and 1 low voltage supply CROP/ WALTA/ SALTA recycle detectors from the Chicago Air Shower Array

4. U.S. Army Photo September 30, 1999 The CROP team at Chicago Air Shower Array (CASA) site

5. CASA detectors’ new home at the University of Nebraska 2000 scintillator panels, 2000 PMTs, 500 low and power supplies at UNL

6. PMMA (polymethyl methacrylate) doped with a scintillating fluor Read out by 10 stage EMI 9256 photomultiplier tube Recycling material inherited from The Chicago Air Shower Array 2 ft x 2 ft x ½ inch

7. EMI Photomultiplier tubes are working Typical efficiency of counters 85% - 95%

8. CROP Workshops

9. Oscilloscope training

10. Tearing the old CASA counters apart

11. Scraping, sanding and polishing

12. Wrapping & light-tighting

13. Electronics lessons

14. LabView (PC) At-a-glance monitoring of incoming data Graham Wheel (UWash) Jared Kite (UNL) Monitoring Program for Data Acquisition Card

15. Cosmic Ray Observatory Project Collecting Data with CROP DAQ Card Interface Doing an Efficiency Scan 1.Disconnect the 4 signal cables from the DAQ card. These are the cables that connect to your 4 detectors. 2.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). http://crop.unl.edu/tutorials/ Online help and tutorials available.

16. On-Line Oscilloscope Cheat Sheets http://unlhep2.unl.edu/~CROP/oscihomepage.html

17. April 2001 participant meeting at UNL Marian High School students presenting results and discussing cosmic rays with Prof. Jim Cronin, University of Chicago

18. Barometric Pressure (mmHg) 727 747 4-Fold Coincidences / 2 hours 3000 4200 Statistical error bars shown 1.3% decrease per mmHg Marian High School’s Measurement of Cosmic Ray Rate vs. Barometric Pressure http://marian.creighton.edu/~besser/physics/barometer.html

19. Mount Michael Benedictine High School “The Science Teacher”, November 2001

20. The Washington-Area Large-Scale Time-Coincidence Array http://www.phys.washington.edu/~walta Seattle area map showing schools CROP’s closest relative University of Washington, Seattle Jeff Wilkes, et al. also using refurbished CASA detectors WALTA / CROP / FNAL collaboration developing DAQ PC electronics card Funding limited, but used QuarkNet association to fund 1 st WALTA workshop, August 2001

21. WALTA/QuarkNet One-week Summer Workshop University of Washington August 2001 Seattle teachers and WALTA staffRefurbishing CASA scintillators

22. 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 SALTA: Snowmass Area Large Time-Coincidence Array Empire Clear Creek High School, Empire, CO

23. Leadville 1 10 miles

24. Polishing scintillator edges outside Conference Center Making detectors light-tight SALTA Workshop, July 2001, Snowmass, CO mass phototube gluing

25. Henderson Mine Visit Dec 4, 2003 hosted by Chip deWolfe Marc Whitley Diana Kruis Nancy Spletzer Aspen High School Basalt High School Clear Creek High School Michelle Ernzen Laura French Lake County School Roaring Fork Valley Hans-Gerd Berns University of Washington Dan Claes University of Nebraska

26. Scouted 3 possible locations between 2800-3900 ft depths 110 power available

27. Can't survey the proposed site, but plan to use spots away from glory hole ( where blasting still common & overhead rock broken up ) Topological graphs and CAD tools can provide good estimates of overburden at survey-able spots. 4 sites have been identified ranging from 3000 – 4000 overburden

28. January 13-15 – Claes visits the SALTA schools to check out condition of detectors and meet with students

29. Cosmic Ray Scintillator Testing Threshold Testing Results Online exponential fit program: http://cms.dt.uh.edu/Faculty/BecerraL/ExpFit.htmhttp://cms.dt.uh.edu/Faculty/BecerraL/ExpFit.htm Results posted by students from Basalt High School Threshold(mv)Hits per minute 20 263885 30 220347 40 133871 50 94560 6054108 7066733 80 31927 90 25696 100 8011 Scintillator Two f(x) = 480410.6452 (.9682754831^ x ) Coefficient of correlation:.9488743319

30. A Threshold Scan Rather than focussing on a single fit to the entire range of data, recognize that two different physics processes are at play. Both generate counts, but with rates that drop off differently with increasing threshold.(Both drop ~exponentially, which is why we use a logarithmic plot). At LOW THRESHOLD we expect to be dominated by noise, which plummets rapidly with threshold. Its exponential drop should ideally look like a straight line on a logarithmic plot. At HIGH THRESHOLD the background noise should be pretty much eliminated, and any additional increase in threshold will actually start cutting into the real signal. Real signals are, on average, larger, so the drop is less severe. This defines two regions with relatively flat (linear) response. Because of the statistical fluctuates common in random events like noise or cosmic ray counts, how straight the lines are may depend on how long you ran at each data point (at least 10-15 minutes should be OK). Of course the two regions overlap, so there's a middle region that curves. But we can focus on the first few… points at each extreme to determine our linear fits, as I have done (by eye) above. We use the intersection of the two lines to select the threshold (which looks to be about 65 mV in the example above to me). It's a nice to try and confirm your selection by eye. Recall you can set trigger threshold on the oscilloscope. A very low threshold will have the oscilloscope almost continuously triggering, revealing a band of noise (see above). Moving the threshold just far enough to kill the noise and give only the flickering images of healthy signals can give you an approximate idea of where the threshold should be set. See if you can confirm this sort of behavior for the setting your scans suggest you use. Recall the DAQ card has a built-in x2 amplifier, so uses thresholds twice the size of the ones you'll need for the oscilloscope trigger (i.e., a threshold of 65mV from the DAQcard scan corresponds to a 32mV trigger threshold on the oscilloscope). Example of follow-up discussion posted in response:

31. Aspen Center for Physics July, 2004: Back for MORE!

32. Aspen Center for Physics Education & Outreach Workshop July 6-8 SALTA schools take over the library, setting up cosmic ray telescopes, for training in the new DAQcard that will be used in all their data-taking.

33. ¼ in lead Detectors telescoped pair with coincidence requirement against noise sandwiched with lead sheet have been reconfigured into muon telescopes At mining level (3000 mwe) the rate for any single (2 ft  2 ft) panel will be low We take two such modules down into the mine May need week(s) long runs We are moving the detectors at 2-3 week intervals

34. with dust a problem for a PC we house a low-power serial digital data logger A portable stand holds each muon telescopes.

35. Desktop Base Station An ~identical pair of modules are running in a fixed location (surface office) to establish our baseline

36. where dust may be a problem for a PC we house the low-power serial digital data logger alongside the DAQcard thanks to Hans Berns’ initial testing with Acumen Instruments Databridge development kit

37. SALTA’s Henderson Project is launched September 29, 2004

38. Clear Creek High School students set up the satellite modules

39. 1 st underground run started 2:12pm 9/28/04 8100 Electrical Shop Clear Creek High School instructor Nancy Spletzer does the Honors Punching the RUN button

40. The future At the conclusion of Henderson measurements revive the original cosmic ray grid plans for SALTA work with schools to plug into CROP-WALTA recruit neighboring schools to expand the grid

41. Wherever/whenever the UNO facility is built I hope to see monitors at the lab entrance (and/or Visitor’s Center) featuring the high school report, so again local schools can feel they are making a contribution to the experiment. At the same time, their data will be part of the CROP-WALTA network. a cosmic ray grid on area schools will continuously monitor the local cosmic "weather" reporting it as close to live as we can to the lab.