Photodegradation mechanisms of tetraphenyl butadiene coatings for liquid argon detectors

We report on studies of degradation mechanisms of tetraphenyl butadiene (TPB) coatings of the type used in neutrino and dark matter liquid argon experiments. Using gas chromatography coupled to mass spectrometry we have detected the ultraviolet-blocking impurity benzophenone. We monitored the drop i...

Full description

Bibliographic Details
Main Authors: Jones, Benjamin James Poyner (Contributor), VanGemert, J. K. (Author), Conrad, Janet (Contributor), Pla-Dalmau, A. (Author)
Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor)
Format: Article
Language:English
Published: Institute of Physics Publishing, 2014-07-11T17:42:27Z.
Subjects:
Online Access:Get fulltext
LEADER 01903 am a22002413u 4500
001 88282
042 |a dc 
100 1 0 |a Jones, Benjamin James Poyner  |e author 
100 1 0 |a Massachusetts Institute of Technology. Department of Physics  |e contributor 
100 1 0 |a Jones, Benjamin James Poyner  |e contributor 
100 1 0 |a Conrad, Janet  |e contributor 
700 1 0 |a VanGemert, J. K.  |e author 
700 1 0 |a Conrad, Janet  |e author 
700 1 0 |a Pla-Dalmau, A.  |e author 
245 0 0 |a Photodegradation mechanisms of tetraphenyl butadiene coatings for liquid argon detectors 
260 |b Institute of Physics Publishing,   |c 2014-07-11T17:42:27Z. 
856 |z Get fulltext  |u http://hdl.handle.net/1721.1/88282 
520 |a We report on studies of degradation mechanisms of tetraphenyl butadiene (TPB) coatings of the type used in neutrino and dark matter liquid argon experiments. Using gas chromatography coupled to mass spectrometry we have detected the ultraviolet-blocking impurity benzophenone. We monitored the drop in performance and increase of benzophenone concentration in TPB plates with exposure to ultraviolet (UV) light, and demonstrate the correlation between these two variables. Based on the presence and initially exponential increase in the concentration of benzophenone observed, we propose that TPB degradation is a free radical-mediated photooxidation reaction, which is subsequently confirmed by displaying delayed degradation using a free radical inhibitor. Finally we show that the performance of wavelength-shifting coatings of the type envisioned for the LBNE experiment can be improved by 10-20%, with significantly delayed UV degradation, by using a 20% admixture of 4-tert-Butylcatechol. 
520 |a National Science Foundation (U.S.) (NSF-PHY-084784) 
520 |a United States. Dept. of Energy (DE-FG02-91ER40661) 
546 |a en_US 
655 7 |a Article 
773 |t Journal of Instrumentation