the ludlum project
Post on 05-Jan-2016
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The Ludlum ProjectAdvisors: Dr. Dan Karmgard
Dr. Randal Ruchti, Mark Vigneault
Teachers: Brian DolezalMark Kirzeder
Students: Eric AndersonBrandyn BaumbaughRuvi Chauhan
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.
Current Focus of Ludlum @ ND
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 Up within a light tight box
GaAsP PMT
Radioactive Source
Scintillating TileWave Shifting Fiber
Light Guide
Tile PMT
Counter PMTs
Experiment Set Up
GaAsP PMT
Scintillating Tile
Counter PMTs
Light Guide
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.
Data Analysis
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 Black Felt 395.6 pvs
DSB-1 Side Edge Tyvek 436.5 pvs
DSF-1 14 Inserted Black Felt 366.9 pvs
DSF-1 Tyvek 395.8 pvs
14 Inserted
Side Edge
Sample Signal Characteristic Data - Incomplete
Material Coincidence Fiber Position Tile 0 1 2 3 4 DT
Y-11 T1-T-D 1/4 in Felt 0 79.1 18.9 2 0 4.67
DSF-1 T1-T-D 1/4 in Felt 0 96.3 3.67 0 0 5
DSF-1 T1-T-D 1/4 in Tyvek 0 89 9.67 1.33 0 4.67
DSB-1 T1-T-D 1/4 in Tyvek 0 88 11 1 0 3.67
DSB-1 T1-T-D 1/4 in Felt 0 93.7 6.33 0 0 4.33
Test – LED Attenuation
A new test UV LED’s
(370nm, 395nm, 400nm, & 405nm) Quicker Easier
Experimental Set Upwithin a light tight box
Sr 90
Fiber
Apiazon
LED
Photo Diode
Experimental Set Up
Fiber
LED
Photo Diode
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
4CN-HBT f. 12 with 370 LED
Collective Average 4 CN-HBT (all fibers) 370 LED
Collective Average 4CN-HBT (all fibers) 370 LED
4CN-HBT (all fibers/all LEDs)
Results
Attenuation Lengths (m)
LED (nm)
Fibers 370 395 400 405
4CN-HBT 5.42 6.25 6.19 5.86
Ox-550 4.55 4.73 4.24 4.88
New 3HF 4.71 5.10 4.18 4.97
Old 3HF 2.89 2.92 2.87 3.04
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