1. 1 Photocathode development and simulation-2 K. Attenkofer, Z. Insepov (ANL) V. Ivanov (Muon Inc)

2. 2 Pillar structure

3. 3 Transmission vs reflection modes electron Transmission modeReflection mode Photocathode Glass Window Photon vacuum 1  m Reflective layer

4. 4 Reflection Mode vs. Transmission Mode Quantum Efficiency Wavelength Factor ~ 1.5 to 2 x higher [D.Ferenc, UC SD]

5. 5 Hybrid photocathode Water Glass window GaAsP Photon Al protective layer 1  m GaAsP electron Photon Photocathode #1 Cs-O NEA layer Photocathode #2

6. 6 Water Glass window GaAsP Al protective layer 1  m GaAsP electron Photocathode #1 Photocathode #2 Cs-O NEA layer Hybrid photocathode Photon

7. 7 Inclined pillars Glass window photon Secondary electrons

8. 8 Pillar coating d ~ 100 nm D ~ 500 nm photon h ~ 1-10 um TiO2+GaAs+CsO coatings Glass GaAsP Al 1  m electron Cs/O water

9. 9 GaAs emission properties