light collection with fiber optics
Download
Skip this Video
Download Presentation
Light Collection with Fiber Optics

Loading in 2 Seconds...

play fullscreen
1 / 9

Light Collection with Fiber Optics - PowerPoint PPT Presentation


  • 65 Views
  • Uploaded on

Light Collection with Fiber Optics. Christopher Crawford EDM Collaboration Meeting 2006-05-25. Review. Steve Williamson presentation (2004-12) Simulations with GuideIt MC code Downstream guide (behind beam stop) Single-ended edge guide 0.3 K to 300 K Transition guide

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Light Collection with Fiber Optics' - rebekah-spence


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
light collection with fiber optics

Light Collectionwith Fiber Optics

Christopher CrawfordEDM Collaboration Meeting2006-05-25

review
Review
  • Steve Williamson presentation (2004-12)
    • Simulations with GuideIt MC code
    • Downstream guide (behind beam stop)
    • Single-ended edge guide
    • 0.3 K to 300 K Transition guide
  • NIST Magnetic UCN trap
    • Also simulated with GuideIt
    • Measured efficiency of similar geometry
    • 360 keV (source) /16 eV (UV) * 35% (prompt UV)* 0.1 (PMT eff.) * epsilon = 6 p.e. (measured)
    • epsilon = 0.8 % (acceptance * attenuation)
problem
Problem
  • Efficiency too low:
    • 3He + n -> p + t + 700 keV (12 p.e.)
    • Need 40 p.e. for optimal PID
  • Charge:
    • Investigate Fiber Optic Bundles (FOB)
    • Collect light from top/bottom, not end
    • Advantage: larger surface area
material properties
Acrylic Light Guide

d = 150-500 cm (atten)

n = 1.508 (index refr.)

thc = 41.5 deg

Fiber Optic Bundle

`Toray` 3 mm O.D.

d ~ 21 m (0.2 dB/m)

Core: no = 1.492

Clad: nc = 1.408

10 micron thick

N.A. = 0.5

Packing fraction = 90%

Sample shipped to LANL

Material Properties
enhancements
Enhancements
  • Capture photons back-propagating through the 3He cell
    • Light guide inefficient for this angle
    • Not quite a factor of 2
  • Optical fibers without cladding
    • Still total internal reflection

NA = 1.10, theta = 42.7 deg, Omega=2.016

A = 0.16 = 16 x (guide)

enhancements1
Enhancements
  • Increase distance from TBP, and
  • Insert fibers at optimal angle
    • Look at greater density of TBP from ends
    • Ideal: semi-circle interface, A=0.5

ideal

TPB

realistic

FOB

enhancements2
Enhancements
  • Use larger n guide
    • Polystyrene (TPD): n=1.55-1.59
    • Larger n guide refracts to less divergence
  • Use tapered light guide
    • Increase effective critical angle
    • Less wall bounces
conclusion future work
Conclusion & Future Work
  • Geometry and Material optimizationscan regain 40 photo-electrons
  • Need to simulate with GuideIt
  • Integration: which designs are realistic?
ad