Today I picked up two 2FT x 4Ft x 0.125" thick strips of stock EPDM and BUNA-N (Nitrile) material from BC Rubber Supply.  A copy of the Packing Slip is attached.  Here is the information from the Sample Sheet:

Nitrile 60 Commercial Grade

Type: Moderate Oil Resistance

Temp. Range: -30 to 190 (does not specify C or F... assuming C)

Ozone Resistance: Poor

Tear Resistance: 240 lbs/in.

Elongation: 500%

Tensile Strength: 1700 psi

EPDM AB-563 Premium Grade

Type: Excellent thermal & Chemical Resistance

Temp Range: -40 to 250 F

Ozone Resistance: Excellent

Tear Resistance: 145 lbs/in

Elongation: 500%

Tensile Strength: 890 psi

Sample preparation notes:

- Rectangular cross-section rings of this material were cut by hand using a compass-type rotating blade cutting tool on a work bench.  The process of cutting the rings to get the cross section as even as possible all around was finicky and required several attempts.

- The rubber rings cut from the stock material were nominally 8.040" OD X 7.66" ID x 0.125" thick, but this varied likely within +/- 0.020" each on the OD and ID due to the lack of precision in the cutting process.

- In the end, the final rubber rings cut were adequate to fit in the 8" double-sided aluminum carrier ring seal grooves without falling out.  For the future, a rule die would be best for cutting the samples and one should be made to prepare the next planned set of test samples.

- The strips were cleaned with Methanol.

- Two 8" double-sided aluminum carrier rings were cleaned and prepared, one packed with EPDM and one packed with BUNA-N (Nitrile). 

- Break-away sample coupons for analysis of the neutron flux received by the 6061-T6 aluminum carrier ring material were notched into the carrier ring fins with a bandsaw and deburred.  Two coupons nomially 0.25" x 0.25" x 0.125" thk were prepared for each ring.  These coupons will be broken off for analysis upon retrieval of these test samples.

- A make-shift lifting yoke to allow us to lower the rings to their resting place over the M9/T2 flange was prepared with and aluminum strip and bail wire (see attached photos).

Our plan for Monday Oct 22nd is to lower the two test samples on their lifting yoke and bail and rest them above the M9/T2 flange before covering up the area with blocks. 

The date and time of insertion will be recorded and samples will live there and receive operating dose from the beam and T2 target until the next time the M9 T2 area is uncovered and we can retrieve them for analysis and testing. 

The reason the 8" aluminum double-rings are used is because we plan to build a vacuum leak test jig using the standard 8" spring-loaded knife edge flanges typical of the designs at the M9T2 and M20T2 joints. 

The irradiated samples will be tested in this jig and compared to samples prepared using the virgin (non-irradiated) material  A test plan will be written to encompass the exact set of mechanical tests the samples will undergo to compare them to the virgin baseline.