1. Developing the Collaboration P McIntosh STFC Daresbury Laboratory

2. Activities @ Daresbury SRF (for PIP-II): 352/650MHz Cavity Preparation & Testing: – HPR – BCP – 1.5m diameter cryostat – 150W 2K liquefier Cryomodule Integration: – 6 x 4.9m ISO 4 (Class 10 cleanroom) Cavity testing post ESS high-beta cavity delivery by end 2020 and CM integration post HL-LHC crab pre-series CM delivery end 2019 Electron-Cloud SEY (triggered by Eric’s talk yesterday re: PIP-III main injector): Laser processing of beam vessels to reduce SEY to <0.8 Collaboration underway with CERN for HL-LHC and FCC

3. ESS High-Beta (0.86) Cavities STFC requested to procure and test all high-β SRF elliptical cavities: Nb procurement Dressed cavity fabrication with industry Vertical tests Shipment to CEA Saclay Total of 84 dressed 704 MHz cavities: Plus 4 possible spares. Operating specification: 20 MV/m @ Q o > 5 x 10 9 Testing specification: 23.9 MV/m @ Q o > 5 x 10 9 Testing rate of ~1 cavity/week

4. SRF Hall/Cleanroom Layout BCP not included in ESS scope

5. HL-LHC Pre-Series CM Design pre- series CM CM construction & integration @ DL SM18 cold tests @ CERN

6. Laser treatment of metals in air or noble gas atmosphere Copper Stainless Steel New Technology for SEY Reduction Laser Induced Micro/Nano Structure Surfaces (LIMNSS) 6

7. Advantages Over Other Methods 7 There is no need for vacuum or clean room facilities. The laser is capable of fabricating the desired micro/nanostructure in a single step process. Hierarchical structures containing both micro- and nanostructures can be created in a single machining step Machining is performed through a beam of light and thus contactless. The process is applicable to the surfaces of any 3D object. Many parameters can be easily adjusted resulting in a great variety of possible structures. It is possible to lase in many different environments, such as gases, liquids, or in a vacuum.

8. First results on SEY Reduction as a function of incident electron energy UntreatedLaser treated Original data June 2014 Valizadeh et al. Applied Physics Letters 12/2014; 105(23): 231605 And STFC Patent 8 Copper Stainless-Steel Aluminium

9. δ max as a function of electron dose for Al, 306L SS and Cu 9 Sample InitialAfter conditioning to Q max δ max E max (eV) δ max E max (eV) Q max (C  mm -2 ) Black Cu 1.126000.78600 3.5  10 -3 Black SS1.129000.76900 1.7  10 -2 Black Al1.459000.76600 2.0  10 -2 Cu1.903001.25200 1.0  10 -2 SS2.253001.22200 1.7  10 -2 Al2.553001.34200 1.5  10 -2 Reduction of δ max after conditioning is attributed to change in surface chemistry due to electron-­beam induced transformation of CuO to sub-­stoichiometric oxide, and build-up of a thin graphite C­‐C bonding layer on the surface.

10. Surface resistance measurements 10 Test cavities (3.9 and 7.8 GHz): – The simulation results obtained with Microwave Studio – Fabricated from Al. Samples: – a 100-mm diam. disk – Bulk Cu – 5-  m thick deposited Cu on Si wafer – Type A on copper – Type C on copper

11. 7.8 GHz Surface Resistance Measurements 11 BulkRoughnessfor 7.8 GHz Sample R (  m) r.m.s. RA (m) R s calc (  m) R s meas (  m) Cu bulk 1.68  10 -8 4.09  10 -7 2.86  10 -2 2.70  10 -2 Cu(5  m)/Si1.68  10 -8 9.08  10 -9 2.27  10 -2 2.84  10 -2 LIMNSS-I on Cu 1.68  10 -8 -- 5.9  10 -2 Al bulk 2.82  10 -8 4.05  10 -7 3.40  10 -2 3.85  10 -2 Nb bulk 1.54  10 -7 (1.0  10 -6 ) 8.06  10 -2 6.75  10 -2 304-L 7.2  10 -7 1.44  10 -6 1.60  10 -1 1.68  10 -1

12. What else do we need to know about LIMNSS? SEY in magnetic fields 0.02T 1T SEY at cryogenic temperatures (relevant for HL-LHC and FCC) Photo-electron emission yield (PEY): – PEY in a magnetic field: requires an access to a SR beamline 12

13. Testing At CERN for HL-LHC Liner has been prepared by STFC ASTeC Vacuum Science group for e-cloud test in SPS at CERN in Jan 16 13 Note: We are also looking for further test opportunities in Other Particle Accelerators

14. E-cloud Mitigation in EuroCirCol EuroCirCol is a H2020 program for FCC studies. WP4 includes e-cloud mitigation studies in FCC (led by STFC ASTeC). Started in June 2015 for 4-years. Collaboration with CERN, ANKA, ELBA and INFN. 14