1. P8 Shutter Review July 26, 2005 P8 – Monochromatic Photon Shutter Presented by C. Chaffee and L. Gades

2. P8 Shutter P8 shutter in 9-BM-A

3. P8 Shutter Locations P8-20 3-ID-C 11-ID-A (3) 18-ID-C 19-ID-C 22-ID-C P8-30 1-BM-B 9-BM-A 11-BM-A 19-BM-C 22-BM-C P8-50 NID-X 24-ID (ordered 2) P8-60 3-ID-B 16-ID-A 30-ID P8 modified 6-ID-A P8-81 5-BM-A There are 18 P8 shutters at the APS.

4. P8 Shutter Features Movable mono beam shutter Beam collimator Pumping Port Tungsten collar at exit Standard actuator with copper shaft Redundant tungsten mono shutters work as a unit

5. P8 Shutter Features Cooling “fins” increase SA:V ratio Cooling not really necessary Tungsten melting point: 3422 o C

6. How is the P8 different? No white beam stop No bremsstrahlung collimator P4, P5, P6, P7 are generally used in conjunction with a double crystal monochromator, which shifts the mono beam 35mm above the white beam path. No water cooling Cooling fins

7. How is the P8 different? Mono beam only Energy comparison White beam ~1000 keV Pink beam ~30 keV or less Mono beam ~1 eV

8. How is the P8 different? Mono beam only Stopping power White beam shutter ~6000 watts Mono beam shutter ~10 watts Tungsten shielding White shutter = 180mm Mono shutter = 60mm

9. Why use a P8 Shutter? Cheap! Smaller Less complicated design For beamlines that do not require a WBS For beamlines that do not require a bremsstrahlung collimator Standard actuators Easy to reproduce

10. P8 Typical Failure Modes Pneumatic actuators: designed to be exercised regularly, but are used only intermittently. Cup seals Become set Right or wrong, past personnel put lubrication in the cylinders Bearings

11. P8 Typical Failure Modes Inconvenient when it does fail No ports for access to the cylinders Entire actuator must be removed

12. P8 Typical Failure Modes Shutter is designed to “fail safe.” If the pneumatics were to fail, the tungsten block would fall into the beam path Tungsten falls farther than it needs to Even if shutter stroke is slightly off, the tungsten still falls far enough to stop the beam Hard stop below the tungsten It cannot fall through, beyond the beam path

13. Variations on the P8

14. P8-20: ID Mono Shutter Standard P8 design for ID beamlines Stroke = 31mm Aperture = 3.25” x 0.75”

15. P8-30: BM Mono Shutter Standard P8 design for BM beamlines Stroke = 31mm Aperture = 4.825” x 0.75”

16. P8-20 vs. P8-30 ID vs. BM: It’s all in the collimator aperture BM Aperture = 4.825” x 0.75” ID Aperture = 3.25” x 0.75” P8-20P8-30

17. P8-40: Temporary Design Entire P8 is turned 90 o to provide a vertically tall aperture: 0.75” wide x 3.25” tall Extension Spring

18. P8-60: Large Vertical Aperture Re-designed P8-40 Cylinder vertically oriented Aperture = 0.75” x 3.25” Stroke = 108mm Aperture is turned 90 o to allow for multiple offsets of the mono crystals

19. P8-60: Large Vertical Aperture Contrast the stroke of the P8-60 with other P8 shutters 108mm Standard P8 P8-60 31mm

20. P8-60: Large Vertical Aperture Contrast the stroke of the P8-60 with other P8 shutters 31mm 108mm Standard P8 (3-ID-C) P8-60 (3-ID-B)

21. P8-50: Compact Design P8 designed for the NID-X backscattering beamline Stroke = 31mm Aperture = 2.00” x 1.00”

22. 6-ID-A Modified P8: What’s different? Geometry of the vacuum chamber Pneumatic actuator design Side port for electromagmetic metal foil: a diagnostic tool Got in the way and was blocking the beam Removed

23. Acknowledgements Thanks to the following people for contributing reference information MU-CAT Personnel Doug Robinson BESSRC-CAT Personnel Mark Beno APS Personnel Mohan Ramanathan