Material Compatibility Studies

We don't usually think about material compatibility when we hear the words "neutrino detector" but it is a very important aspect in an experiment. Especially if you plan on building a detector that will cost several million dollars, you'd best make sure that everything that goes inside it won't break down and ruin your experiment! That is why it is crucial to test every possible material that may go inside your detector and make sure it is compatible with the liquid or solution the detector will be filled with (e.g. gadolinium-doped water, water-based liquid scintillator).

Below is a table of all the materials that are being tested so far for ANNIE and WATCHMAN. Clicking on the material name will bring you to the Box app with folders containing images, plots, and spectrum data.

 

Soak Solution

 Description

pure water Deionized water (either purchased or from our deionized water machine)
 1% Gd-doped solution (unfiltered) A gadolinium-enhanced solution prepared with a supply of gadolinium (III) sulfate from Fermilab, later determined to be contaminated with nitrates. The 1% (by mass) solution is prepared by dissolving 10g of the compound in a 1L solution.
 1% Gd-doped solution (filtered [date]) A Gd-enhanced solution prepared with the Fermilab supply of low purity gadolinium (III) sulfate. The solution is cleaned by passage through a filtration system consisting of (in the order of flow) a TOC lamp, a UV lamp, a 5 micron filter, and a 0.5 micron filter. The nitrates are not removed by this method.
1% "normal" Gd-doped solution A Gd-enhanced solution prepared from a supply of higher purity gadolinium (III) sulfate. It is labeled "normal" because that is what was written on the bag.
0.2% Gd-doped solution A lower concentration of Gd solution
0.01% nitric acid A nitric acid solution prepared by dilution of a stock HNO3 solution
 5% WbLS 5% water-based liquid scintillator

 

 

  

Material

Origin

Soak Liquid

Start Soak Date
(mmddyyyy)

 Notes

X  PVC liner Kentain 1% Gd-doped solution (unfiltered)  08/04/2017
  • The acidity/low pH of the solution may be the main contributor of the quick degradation of the material
X  PVC liner Kentain 0.2% Gd-doped solution 11/24/2017
  • Soaked in a lower concentration solution to determine whether the amount of Gd contributes to the degradation of the material
  • Even at lower concentrations, degradation of the material occurs but at a slower rate
X  PVC liner Kentain 0.01% nitric acid solution 11/24/2017
  • Soaked in a nitric acid solution to determine whether the acidity/low pH contributes to the degradation of the material
  • Break down of the material can be seen at low pH
   PVC liner Kentain 5% WbLS (opened 01/16/2018)  01/26/2018  
X  PVC liner (black) Kentain 1% Gd-doped solution (semi-clean) 04/10/2018
  • Leaches a chemical into solution
  • Needs to be thoroughly clean and retested
   WATCHBOY PMT  Hamamatsu  1% Gd-doped solution  07/28/2017
  • No issues so far
   LUX PMT  Hamamatsu  1% Gd-doped solution  08/01/2017
  • No issues so far
   PVC pieces Fermilab  1% Gd-doped solution 08/04/2017
  • Fraying on faces of PVC cubes but most likely due to cutting
X  RG59 cable (original, 2nd attempt, no writing) Fermilab  1% Gd-doped solution  06/30/2017 (original)

  • Even after a thorough cleaning and removal of writing printed on the cable, the material of the coating is not compatible with the Gd solution; transparency is worsened
   Stainless steel pipe (intersection, square, square12) Fermilab  1% Gd-doped solution 08/04/2017 (intersection)
07/06/2017 (squares)
  • no issues so far
   Stainless steel hex nuts  Fermilab  1% Gd-doped solution  06/30/2017
  • no issues so far
 
   Stainless steel screws (small, regular)  Fermilab  1% Gd-doped solution 06/30/2017 (small)
08/04/2017 (regular)
  • no issues so far
   Stainless steel screws (with hex nuts)  Fermilab  1% Gd-doped solution 06/30/2017
  • no issues so far
   Stainless steel wires partially wrapped in plastic sleeve (circular, straight)  Fermilab  1% Gd-doped solution 08/04/2017
  • fluffy-looking particles floating around in solution were found, but may be due to contamination
   Stainless steel springs  Fermilab 1% Gd-doped solution  06/30/2017
  • no issues so far
   Stainless steel ziptie  Fermilab  1% Gd-doped solution  06/30/2017
  • no issues so far
X  Plastic o-ring  UC Davis machine shop  1% Gd-doped solution  08/23/2017
  • degradation can be seen on surface of the o-ring (pulp-like material)
   PVC (1" tube)  UC Davis  5% WbLS 10/24/2017  
X  Henkel Loctite STYCAST 1266 Epoxy Ellsworth Adhesives  5% WbLS 10/10/2017
  • Holds together PVC and glass; intended for gluing together PMT housing structures
  • Leaching occurs and introduces chemicals into WbLS (seen in spectrum)
  • Excess epoxy peels off the glass
   Teflon tape    1% Gd-doped solution (filtered 12/06/2017) 10/25/2017
  • Initial sample was contaminated
  • Second attempt shows no issue so far
   Kapton tape    1% Gd-doped solution (filtered 12/06/2017) 10/25/2017
  • Intended to prevent and protect stainless steel structures from rust
  • Adhesive side of the tape leaches into solution
  • After initial leaching, UV-vis spectrum remains stable and adhesiveness still remains
X  SABA Ecoseal Bio HM SABA Adhesives & Sealants / Sheffield  1% Gd-doped solution (filtered 12/06/2017) 12/23/2017  
X  SABA EcoSeal Bio HM SABA Adhesives & Sealants / Sheffield  5% WbLS  12/23/2017
  • Transparency in WbLS solution decreased in the wavelength range of 350nm and 400nm
X  Sikaflex TS Plus Sika AG / Sheffield  1% Gd-doped solution (filtered 12/06/2017) 01/15/2018  
X  Sikaflex TS Plus Sika AG / Sheffield  5% WbLS 01/15/2018  
   Tyvek polyethylene fabric (white) McMaster-Carr  1% Gd-doped solution (filtered 12/06/2017) 01/26/2018  
X  Tyvek (black) Material Concepts (certified DuPont Tyvek vendor)  1% Gd-doped solution (filtered 12/06/2017) 03/08/2018
  • Leaches into solution, even in deionized water
   PET (clear polyester film) McMaster-Carr  1% Gd-doped solution (filtered 12/06/2017) 01/26/2018  
X  PET (black polyester fabric)  McMaster-Carr  1% Gd-doped solution (filtered 12/06/2017) 01/26/2018
  • Leaching of chemicals into solution occurs
  • Solution seems to seep into the material and prevents fabric from floating
X  BioSeal 197 Thin Film Technology 1% Gd-doped solution (filtered 12/06/2017; reagent grade 11/21/2017
  • Many issues with this epoxy sealer
  • Leaching occurs to a great extent, even in a reagent grade Gd solution
  • Pulp-like substance fills solution
   LDPE liner (black) ULINE

1% "normal" Gd-doped solution

10/05/2018
  • Experienced contamination by what appears to be mold
   Low-density polyethlyene (LDPE) Fermilab

1% "normal" Gd-doped solution

12/20/2018

 

X  Tedlar (black)   1% "normal" Gd-doped solution  11/07/2018 
  • Leaching of chemicals into solution occurs and transparency of Gd solution is decreased 

 

 

Below is a more detailed (although incomplete) record of all the materials currently being tested. Plotting tools for spectra comparison will be implemented in the future.

(last updated May 2, 2019 at 01:07)