A Factor of Four Increase in Attenuation Length of Dipped Lightguides   for Liquid Argon TPCs Through Improved Coating
  This paper describes new techniques for producing lightguides for detection of scintillation light in liquid argon time projection chambers. These can be used in future neutrino experiments such as SBND and DUNE. These new results build on a dipped-coating technique that was previously reported and is reviewed here. The improvements to the approach indicate a factor of four improvement in attenuation length of the lightguides compared to past studies. The measured attenuation lengths, which are >2 m, are consistent with the bulk attenuation length of the material. Schematics for a mechanical dipping system are provided in this paper. This system is shown to result in coatings with < 10% variations 
Z. Moss, J. Moon, L. Bugel, J.M. Conrad, K. Sachdev, M. Toups, T.   Wongjirad
physics.ins-det hep-ex