关注：

1) UPS和XPS能量激发的原理

2) 氦灯与微波源

中国科学院高功率微波源与技术重点实验室

http://www.ie.ac.cn/jgsz/kybm/sysmk/gglwby/

http://www.cas.cn/rc/gzdt/201405/t20140522_4124968.shtml

摘录：

光谱光源

http://baike.baidu.com/link?url=SgWQZBnXcwiVeQ3_Kv7UlqgFkVnxo88hkHoNm21x9BElsfxviHIfFnF4uuXhBjL_w8BvlVjg7RJGLIgnG_M75K

氢灯和氦灯

      分别为能量辐射稳定的氢光谱（波长431.4nm、486.1nm和656.3nm）和氦光谱（波长706.5nm和 587.6nm）的辉光放电光源。

      供各种光学仪器如干涉仪、折射仪等作配套件使用。放电管内充有高纯度氢或氦,灯带有能加大贮气体积的附加部分,以维持恒定的气压，从而使放电比较稳定。放电部分制成内径为2～3mm的毛细管，以使辐射光度集中。

汞齐灯  

     以汞作基金属,充入适量镉和锌制成的金属蒸气弧光放电光源。除辐射汞的特征谱线外，还辐射位于汞谱线间的镉和锌的特征谱线（波长643.8nm、636.2nm、632.5nm、631.6nm、546.1nm、508.5nm、481.0nm、435.8nm和404.7nm等）。汞齐灯用在分光仪上作波长标定时，不必再用其他单色光源，且能使分光仪的波长标定更为方便和正确。在冶金、医疗、物理、化学测试中得到广泛应用。

http://en.wikipedia.org/wiki/Ultraviolet_photoelectron_spectroscopy

Basic Theory

If Einstein’s photoelectric law is applied to a free molecule, the kinetic energy () of an emitted photoelectron is given by

where h is Planck’s constant, ν is the frequency of the ionizing light, and I is an ionization energy for the formation of a singly charged ion in either the ground state or an excited state. 

   According to Koopmans' theorem, each such ionization energy may be identified with the energy of an occupied molecular orbital. The ground-state ion is formed by removal of an electron from the highest occupied molecular orbital, while excited ions are formed by removal of an electron from a lower occupied orbital.

Application 

The UPS measures experimental molecular orbital energies for comparison with theoretical values from quantum chemistry, which was also extensively developed in the 1960s. The photoelectron spectrum of a molecule contains a series of peaks each corresponding to one valence-region molecular orbital energy level. Also, the high resolution allowed the observation of fine structure due to vibrational levels of the molecular ion, which facilitates the assignment of peaks to bonding, nonbonding or antibonding molecular orbitals.

The method was later extended to the study of solid surfaces where it is usually described as photoemission spectroscopy (PES). It is particularly sensitive to the surface region (to 10 nm depth), due to the short range of the emitted photoelectrons (compared to X-rays).

  It is therefore used to study adsorbed species and their binding to the surface, as well as their orientation on the surface.^[5]

  A useful result from characterization of solids by UPS is the determination of the work function of the material. An example of this determination is given by Park et al.^[6] Briefly, the full width of the photoelectron spectrum (from the highest kinetic energy/lowest binding energy point to the low kinetic energy cutoff) is measured and subtracted from the photon energy of the exciting radiation, and the difference is the work function. Often, the sample is electrically biased negative to separate the low energy cutoff from the spectrometer response.