the ludlum project

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