Nebraska s Statewide Outreach and Education Experiment The Cosmic

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

CROP article in Lincoln Journal Star, 7 August 2003

The Chicago Air Shower Array CROP/ WALTA/ SALTA recycle detectors from the Chicago Air Shower Array • Located in the Utah Desert • 1089 stations, 15 m spacing each houses 4 scintillators w/tubes 1 high and 1 low voltage supply • covering 0. 23 square km

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

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

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

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

CROP Workshops

Oscilloscope training

Tearing the old CASA counters apart

Scraping, sanding and polishing

Wrapping & light-tighting

Electronics lessons

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

Online help and tutorials available. http: //crop. unl. edu/tutorials/ 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. 2. These are the cables that connect to your 4 detectors. 2. Open the CROP_DAQ Lab. VIEW 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).

On-Line Oscilloscope Cheat Sheets http: //unlhep 2. unl. edu/~CROP/oscihomepage. html

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

Marian High School’s Measurement of Cosmic Ray Rate vs. Barometric Pressure 4200 4 -Fold Coincidences / 2 hours • Statistical error bars shown • 1. 3% decrease per mm. Hg 3000 727 Barometric Pressure (mm. Hg) 747 http: //marian. creighton. edu/~besser/physics/barometer. html

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

The Washington-Area Large-Scale Time-Coincidence Array http: //www. phys. washington. edu/~walta • 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 Quark. Net association to fund 1 st WALTA workshop, August 2001 Seattle area map showing schools

WALTA/Quark. Net One-week Summer Workshop University of Washington August 2001 Seattle teachers and WALTA staff Refurbishing CASA scintillators

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 • Clear Creek High School, Empire, CO

1 Leadville 10 miles

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

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

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

• 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

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

Results posted by students from Basalt High School Cosmic Ray Scintillator Testing Threshold Testing Results Scintillator Two Threshold(mv) Hits per minute 20 263885 30 220347 40 133871 50 94560 60 54108 70 66733 80 31927 90 25696 100 8011 f(x) = 480410. 6452 (. 9682754831^x) Coefficient of correlation: . 9488743319 Online exponential fit program: http: //cms. dt. uh. edu/Faculty/Becerra. L/Exp. Fit. htm

Example of follow-up discussion posted in response: 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 a each data point (at least 10 -15 minutes should be OK). Of course the two regions overlap, so there's a middle

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

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.

Detectors have been reconfigured into muon telescopes • telescoped pair with coincidence requirement against noise • sandwiched with lead sheet ¼ in lead • 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

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

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

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

SALTA’s Henderson Project is launched September 29, 2004

Clear Creek High School students set up the satellite modules

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

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

Wherever/whenever the UNO facility is built 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. 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.