1. SEM EDS Analysis of Contamination from Ultrasonic Cleaner @ANL 4.07.11 SRF Research Development Rs = G/ Q0 AH ext= NΦ0 K n = 2e 2 V n 2 /mω 2 g d 2 P diss = ½ AR s H 2

2. Sample prep  Samples of unknown particulate were brought to IB3. Particulate was on a ‘clean-room’ wipe.  Particulate transferred to conductive surface using double-sticky carbon tape.  Carbon tape mounted on large copper sample for ease of viewing.

3. EDS: Energy Dispersive x-ray Spectrometry Primer  Energetic electrons strike a sample and yield a number of by-products including x- rays.  X-rays have characteristic energies/wavelengths that can then be detected.  Recall that energy is related to wavelength:  E=hc/λ or E= 12.4/λ

4. EDS  X-rays are collected with a liquid nitrogen cooled solid state detector.  Qualitative elemental analysis is done to determine which elements are present and their relative abundance.  Problems: Incorrect sample geometry: needs to be tilted toward detector Contamination- the biggest problem Artifacts: escape peaks from detector- SiLi crystal

5. SEM Image of Sample 1

6. EDS Area for Analysis

7. Analysis Results From Sample 1 Area ElementWeight %Atomic % S1.232.51 Cr14.3518.09 Mn1.381.64 Fe51.7160.71 Co0.690.76 Ni5.255.86 Tb22.029.09 Ho3.381.34

8. Sample 2 Note that Size > 1 mm

9. Analysis Results from Sample 2 Area ElementWeight %Atomic % Cr28.4029.88 Fe71.6070.12 Total100

10. SEM Image of Sample 3

11. EDS Area of Sample 3 for Analysis

12. Analysis Results from Sample 3 Area ElementWeight %Atomic % Cr17.9919.17 Mn1.101.11 Fe70.5669.97 Co8.628.13 Total100.00

13. Comparison  Two samples of Stainless Steel were obtained from FNAL Cut shop.  One sample was known as SS Type 420 and the other sample was an unidentified SS.

14. SS Type 420 From FNAL Cut Shop

15. Analysis Results for SS Type 420 ElementWeight %Atomic % Cr14.5815.49 Fe85.4284.51 Totals100.00

16. SS Unknown Sample From Cut Shop

17. Analysis Results From Unknown ElementWeight %Atomic % Fe100 Note: This sample is not stainless steel.

18. Additional Test  A strong magnet was used to see if the samples were magnetic.  All samples were magnetic except for the one unknown sample from the cut shop.

19. Conclusions  Samples from the ultrasonic cleaner are Stainless Steel Series 400. They closely match the known sample Series Type 420.  400 Series SAE Steel Grades are Martensitic and Ferritic steels that contain varying amounts of chromium.  Those grades of SS that do not contain any nickel are magnetic.