Experiment 12 - NiSO4

 Cell:

• Cathode:  3.5 cm of exposed 0.25mm Ag wire as close as possible to 1 cm x 2 cm Landauer CR-39 chip
• Anode:  Approximately 5 cm of 0.5 mm Pt wire with Pt screen spot welded on end  
• NO magnets

 Electrolyte:

• 27.5 gm D2O + 0.42 gm LiCl + 0.197 gm NiSO4·6H2O (0.03M NiSO4) 

 Procedure:

• TGP current settings:
  • 0.1 mA for 24 hrs
  • 0.2 mA for 24 hrs
  • 0.5 mA until the solution is clear (generally 14 days or more)
  • 1 mA for 24 hrs
  • 5 mA for 24 hrs
  • 10 mA for 24 hrs
  • 25 mA for 24 hrs
  • 50 mA for 24 hrs
  • 100 mA for 24 hrs

Etch:

• 6 hours in 6.5M NaOH at 68C

Results (Started on 1.2.07 Ended on 1.12.07):

• Cell became clear after 3 days (usually takes two weeks)
• On day four, 24 hours after increasing the current from 0.5 mA to 1 mA, a black mass formed
• On day 5, "the black cloud" took over 3/4 of the cell
• On day 9, the cloud condensed around the cathode and made a sort of gelatinous looking mess.

Day 4			Day 5	Day 9

• Upon removing the CR-39, there was no evidence or tracks (unlike other runs)
• After etching for 1 hour in 68C 6.5M NaOH, wavy lines appeared on either side of where the cathode was, as well as a cloudy damage to the bottom 1/3 of the chip
  • very similar lines can be seen in Experiment B

Wavy lines and damage

• After 2 hours of etching, the wavy lines remain, but the cloudy damage is gone