Abstract
The Cosmic Ray Observatory Project (CROP) at University of Nebraska/Lincoln and the Washington Area Large-scale Time coincidence Array (WALTA) at University of Washington/Seattle are among several outreach projects siting cosmic-ray detectors at local high schools in cities around North America, to study the origins and interactions of high-energy cosmic rays. In a collaboration between QuarkNet, the outreach program based at Fermilab, CROP, and WALTA, a low-cost data acquisition electronics card has been developed to collect and synchronize the data from each detector site. The cost per card is under US$500 for parts (for 15 boards), functionally replacing much more expensive electronics crates and modules at each high school site. The card has four analog discriminator inputs for photomultiplier tube signals, a four-channel time-to-digital converter (TDC) for local coincidence and time-over-threshold measurements with ∼ 1 ns resolution, programmable trigger logic via a CPLD and microcontroller, and a built-in low-cost GPS receiver/antenna module (via external cable) to provide event trigger time stamps with 50 ns accuracy. Temperature sensors and a barometer are also integrated to record environmental data along with the counter data. The card connects to any PC or laptop via a standard RS-232 serial port for data output and control. The microcontroller and CPLD are field programmable and thus make the card functionality flexible and easy to upgrade.
Original language | English (US) |
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Pages (from-to) | 926-930 |
Number of pages | 5 |
Journal | IEEE Transactions on Nuclear Science |
Volume | 51 |
Issue number | 3 III |
DOIs | |
State | Published - Jun 2004 |
Bibliographical note
Funding Information:Manuscript received November 15, 2003; revised March 19, 2004. This work was supported in part by the U.S. Department of Energy, Quarknet, and the U.S. National Science Foundation. S. Hansen, T. Kiper, and T. Jordan are with the Fermi National Laboratory, Batavia, IL 60510 USA. D. Claes and G. Snow are with the Department of Physics and Astronomy, University of Nebraska, Lincoln, NE 68588 USA. H. Berns, T. H. Burnett, R. Gran, and R. J. Wilkes are with the Department of Physics, University of Washington, Seattle, WA 98195 USA (e-mail: wilkes@u.washington.edu). Digital Object Identifier 10.1109/TNS.2004.829447 Fig. 1. School-network air shower detector stations. CROP and WALTA use PMTs and counters salvaged from the CASA experiment. Initial installations used NIM crates borrowed from Fermilab, which are being replaced by the DAQ cards described in this paper.
Keywords
- Cosmic rays
- Education
- Elementary particles
- Global positioning system (GPS)
- Particle measurements
- Radiation detectors