Transverse energy spread of photoelectrons emitted from GaAs photocathodes with negative electron affinity
Transverse energy spread of photoelectrons emitted from GaAs photocathodes with negative electron affinity
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DOI：
10.1063/1.120231
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发表时间：
1997-11
影响因子：
4
通讯作者：
S. Pastuszka;D. Kratzmann;D. Schwalm;A. Wolf;A. Terekhov
中科院分区：
文献类型：
--
作者：
S. Pastuszka;D. Kratzmann;D. Schwalm;A. Wolf;A. Terekhov
利用电子束在空间递减磁场中的绝热横向膨胀的新方法，系统地测量了GaAs光电阴极发射电子的平均横向能量（MTE）。能量高于导带最小值的电子被发现与阴极的晶格温度被热化，而电子遭受能量损失之前，他们的发射表现出增强的横向能量。对于同一阴极上的（Cs，O）和（Cs，F）激活层，发现它们的MTE相同，用液氮冷却阴极，高能电子的MTE降低到~ 14 meV。
The mean transverse energy (MTE) of electrons emitted from GaAs photocathodes was measured systematically using a new method based on adiabatic transverse expansion of an electron beam in a spatially decreasing magnetic field. Electrons with energies above the conduction band minimum are found to be thermalized with the lattice temperature of the cathode while electrons having suffered energy losses prior to their emission show enhanced transverse energies. For (Cs,O) and (Cs,F) activation layers on the same cathode the same MTE is found. By cooling the cathode with liquid nitrogen, the MTE of the high-energy electrons was reduced to ≈14 meV.