Two-photon photoelectron spectroscopy

Time-resolved Two-Photon Photoelectron (2PPE) spectroscopy is a time-resolved spectroscopy technique which is used to study electronic structure and electronic excitations at surfaces. The technique utilizes femtosecond to picosecond laser pulses in order to first photoexcite an electron. After a time delay, the excited electron is photoemitted into a free electron state by a second pulse, as shown in Figure 1. The kinetic energy and the emission angle of the photoelectron are measured in an electron analyzer. To facilitate investigations on the population and relaxation pathways of the excitation, this measurement is performed at different time delays.

This technique has been used for many different types of materials to study a variety of exotic electron behaviors, including image potential states at metal surfaces, and even electron dynamics at molecular interfaces.

Basic physics

The final kinetic energy of the electron can be modeled by the following equation:

PPE

PPE may refer to:

Science and medicine

Computing

Organisations

Other uses

Fair

A fair (archaic: faire or fayre) is a gathering of people for a variety of entertainment or commercial activities. It is normally of the essence of a fair that it is temporary with scheduled times lasting from an afternoon to several weeks.

Types of fairs

Variations of fairs include:

Fair (band)

Fair is an alternative rock band currently signed to Tooth & Nail Records. It was created in 2005 from members of Aaron Sprinkle's touring band – Sprinkle, fellow Poor Old Lu alum Nick Barber, Erick Newbill, and Joey Sanchez.

The band released their first album, The Best Worst-Case Scenario, on June 6, 2006.

Members

Discography

Albums

References

External links

Fair (surname)

Fair is a surname and may refer to:

People

Fictional characters

See also