1. Status, Progress and Plans for MEMBrane Hassan Akhtar, Yevgen Bilevych, Hong Wah Chan, Edoardo Charbon, Alexander Cronheim, Harry van der Graaf, Kees Hagen, Gert Nützel, Serge D. Pinto, Violeta Prodanović, Daan Rotman, Lina Sarro, Dennis R. Schaart, John Smedley, Shuxia Tao, Annemarie Theulings Nikhef Jamboree Monday December 15th, 2014

2. Timed Photon Counter - Tipsy Photo cathode + Transmission dynodes + Pixel chip Challenges: Sufficient Secondary Electron Yield (SEY); The ultimate goal: SEY > 4 at primary electron energy < 500 eV. 2

3. Focus Points 3 Dynode fabrication Secondary electron yield Measurements Theory and simulations

4. 4 Fabrication Prototype D2: Flat or curved: Flat Thickness: 25 nm & 50 nm Conductive coating topside H-termination at bottom

5. 5 X-Ray Photo-electron Spectroscopy Measurements 200 eV photon electron detector Target (Si 3 N 4 ) electron Energy (eV) Counts (#)

6. 6 Scanning Electron Microscopy Measurements I top I tmesh I sample I bmesh I bot incoming primary beam (PE) secondary electrons (reflective (RSE) and transmission (TSE)) backscatter (BSE) & punch through (FSE) electrons PE BSE FSE TSE RSE

7. 7 New Setup Two setups: in BNL and at TU Delft, ImPhys (2 post docs arriving) electron gun Timepix dynode under test

8. 8 Electron Affinity Vienna Ab initio Simulation Package Electron Affinity (EA) work function, exiting potential H termination on diamond Negative EA is measured Enhanced secondary electron yield Same is expected for Si 3 N 4 Distance (Å)

9. 9 Transmission Secondary Electron Yield Simulations Primary energy dependenceElectron affinity dependence

10. 10 Conclusions From X-Ray Photo-electron Spectroscopy measurements at Brookhaven From VASP simulations of Electron Affinity Si 3 N 4 with H-termination seems to be a good material for transmission dynodes with high yield. Setups for measurement of transmission secondary electron yield are being build. We positively expect a secondary electron yield of > 4 is achievable

11. 11 Hassan Akhtar, Yevgen Bilevych, Hong Wah Chan, Edoardo Charbon, Harry van der Graaf, Kees Hagen, Gert Nützel, Serge D. Pinto, Violeta Prodanović, Daan Rotman, Lina Sarro, Dennis R. Schaart, Emile Schyns, John Smedley, Shuxia Tao, Annemarie Theulings Thanks to Arjen van Rijn, Michiel Jaspers, Oscar van Petten, Gerrit Brouwer, Wim Gotink, Joop Rövekamp, Bas van der Heijden, Berend Munneke, Henk Peek