SPSU Progress on coatings and grooves M.Taborelli -Progress on C based coatings -Progress on rough coatings -Progress on SEY instrument -Grooves calculation (Pivi, Wang)

SPSU Carbon deposited with Ne: low yield is reproducible…at least in the same geometry Progress on coatings The reason of the low yield might be the higher deposition p with Ne Thickness problem

SPSU Powder, particles and dust Procedure: Before coating: Chamber assembled in coating lab b. 181; Transferred to class 100 clean room in b. 101; Particles measured by “pumping” the chamber with the particle counter. (1 minute runs); Chamber back to b. 181; insert C cathode and perform coating; After coating: Dismount cathode in b. 181; Transfer to clean room in building 101; Measure particles; Progress on coatings

SPSU Progress on coatings Powder, particles and dust Results: Progress on coatings Particles between 0.3m and 0.5m: Particles larger than 0.5m: After coating about 10x more particles. (7.3x for 0.3m, 13x for 0.5m) After gentle hammering no further particles produced. Coated chamber stored under vacuum to check particle evolution after 1 week. run# (min)

SPSU Rough Zr coating (fast deposition rate) 1 μm 100nm Progress on coatings

SPSU SEY or smooth and rough Zr coating: The relative improvement is some 15%.....which means that coating with a layer having delta=1.2 would result in a delta of 1 ( ….. a little more complex due to the energy dependence of the effect) Progress on coatings

SPSU Energy dependence of SEY (new instrument) NB: no influence of various applied potentials, means that the system is stable and values of potentials are not critical Progress on coatings and instrumentation

SPSU Black Au: SEY at 500eV on smooth and black gold Progress on coatings

SPSU Black gold: Au coating by evaporation in Kr Progress on coatings 1 µm 200 nm

SPSU Black Au, energy dependence: maximum is at very high energy Progress on coatings

SPSU Plans for next coatings (….find candidate for next liner) -C(Ne) in tube geometry again; still not sufficiently controlled and reproducible -Particle measurement will be done again after some time on the same chamber to see if any “dust” is generated -More controlled black-Au deposition (for the moment the layer is very inhomogenous in thickness) and characterization for vacuum properties (outgassing due to large surface) -C coating on rough surface (Zr) -BC with lower amount of B than B 4 C: coating done, not measured yet -SiC Progress on coatings

SPSU Plans for SEY instrument Still to be done on new instrument: - Control of focussing (at present some 2 mm spot, but not well controlled above 1000eV): done -Position (distance) with respect to “optics”: done -Beam position stability at low Ep (below 50eV) -Load lock: done -transfer to XPS: will be connected when testing is finished -modify software to measure with scan -SPS transfer chamber Phase II: -Faster acquisition to avoid high dose...however it seems to be already OK -Implement flood gun for conditioning with e-beam

SPSU Grooves, calculation of L.Wang at SLAC on the geometry obtained on copper Progress on grooves 2mm CERN workshop on Copper (S.Atieh, J.M.Geisser) B=0 Assuming delta-max=1.5 1mm 15º Reduction also for B=0 so that we can measure in the lab B=0.2T B=2T