The Ludlum Project Advisors: Dr. Dan Karmgard Dr. Randal Ruchti, Mark Vigneault Teachers: Brian Dolezal Mark Kirzeder Students: Eric Anderson Brandyn Baumbaugh Ruvi Chauhan
Current Focus of Ludlum @ ND • Using LEDs to quickly and accurately determine attenuation length and fiber quality. • Determine signal characteristics based on different geometric arrangements of tiles and fibers and tile coverings.
Test – Scintillation • Used to test all three factors
Variables • Materials • Y-11, DSF-1, and DSB-1 • Tile Coverings • Tyvek, Tedlar, Black Felt • Geometric Arrangements • 8 different arrangements including some that included the fiber in, out of, and on top of the tile.
Experiment Set Upwithin a light tight box Radioactive Source Light Guide GaAsP PMT Tile PMT Wave Shifting Fiber Scintillating Tile Counter PMTs
Experiment Set Up Counter PMTs Light Guide GaAsP PMT Scintillating Tile Tile PMT
Data Gathering • Triple Coincidence • Radioactive source • Data is stored on an oscilloscope • 512 data points per run - averaged • 3 runs were averaged
Calculating Brightness • Brightness is a measure of how much light the fiber transmits • An average run is done to acquire 512 signals • Integration yields total light • Several integrations completed
Data Analysis Average brightness is 1021 units at 1.5 m.
Sample Brightness Data Fiber Type Arrangement Tile covering Avg. Brightness Y-11 14 Inserted Black Felt 431.1 pvs Y-11 Side Edge Tyvek Incomplete DSB-1 14 Inserted Black Felt 395.6 pvs DSB-1 Side Edge Tyvek 436.5 pvs DSF-1 14 Inserted Black Felt 366.9 pvs DSF-1 Side Edge Tyvek 395.8 pvs
Test – LED Attenuation • A new test • UV LED’s (370nm, 395nm, 400nm, & 405nm) • Quicker • Easier
Experimental Set Upwithin a light tight box LED Photo Diode Sr 90 Fiber Apiazon
Experimental Set Up LED Photo Diode Fiber
Attenuation Length • Lout = Lin * exp (-x / Attenuation Length) • Attenuation length is the distance at which 1/e of the original light remains • Light out data was gathered at 0.10m, 0.25m, 0.50m, 0.75m, 1.00m, 1.25m, 1.50m, 1.75m, 2.00m, 2.25m, 2.50m, 2.75m and 2.93m