Measurement of the tradeoff between intrinsic emittance and quantum efficiency from a NaKSb photocathode near threshold

Journal Article · Mon Jun 08 00:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4922146· OSTI ID:22423756

Maxson, Jared; Cultrera, Luca; Gulliford, Colwyn; Bazarov, Ivan ^[1]

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1. Cornell Laboratory for Accelerator-Based Sciences and Education, Cornell University, Ithaca, New York 14853 (United States)

We measure the tradeoff between the quantum efficiency and intrinsic emittance from a NaKSb photocathode at three increasing wavelengths (635, 650, and 690 nm) at or below the energy of the bandgap plus the electron affinity, hν≤E{sub g}+E{sub a}. These measurements were performed using a high voltage dc gun for varied photocathode surface fields of 1.4−4.4 MV/m. Measurements of intrinsic emittance are performed using two different methods and were found to agree. At the longest wavelength available, 690 nm, the intrinsic emittance was 0.26 μm/mm-rms with a quantum efficiency of ∼10{sup −4}. The suitability of NaKSb emitting at threshold for various low emittance applications is discussed.

• OSTI ID: 22423756
• Journal Information: Applied Physics Letters, Vol. 106, Issue 23; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
AFFINITY
ANTIMONY COMPOUNDS
BAND THEORY
PHOTOCATHODES
POTASSIUM COMPOUNDS
QUANTUM EFFICIENCY
SODIUM COMPOUNDS
VISIBLE RADIATION