User:Mitchrockey1/sandbox

Great job! 20/20

Dr. Lineberger has made numerous contributions to the National Institute of Standards and Technology, especially in the measurement of the properties of certain anions using laser photoelectron spectrometry in the 1970’s. The results that Lineberger’s lab derived are still used today when searching NIST’s database for Lineberger’s contributions. Some compounds that Lineberger has studied include but are not limited to nitrogen anion, PO anion, CCl2-, methanediylium anion, and cyclopentadienide anion. Much of this data was published by Dr. Lineberger in the Journal of Physical and Chemical Reference Data. More recently his research has focused on photoelectron spectroscopy of metal cluster anions, published in Journal of Chemical Physics.

Dr. Lineberger’s current research at the University of Colorado, Boulder focuses on three main areas: Caging Dynamics, Photoelectron Imaging, and Photoelectron Spectroscopy. All three areas, however, fit into a niche of physical chemistry. His lab investigates the structure and stability of ions, photoelectron spectroscopy of anions, and photophysics and dynamics of cluster ions using instruments that detect the interaction of laser radiation with mass-selected ion beams. A result of this method is both a high degree of precision and accuracy, but also the ability to measure molecular reaction dynamics in real time. When not using laser radiation to measure reaction dynamics, Dr. Lineberger’s lab group focuses on using photoelectron spectroscopy of negative ions to measure negative ion structure.

The purpose of caging dynamics, or ultrafast photodetachment photoionization spectroscopy is to explore the dynamics of neutral species through electron photodetachment from precursor anions. This research follows the central theme of discovering data about compounds through the study and manipulation of their anions. This technique is also called Charge Reversal Spectroscopy (CRS). Here, a high energy electron beam is shot at a pulsed gas jet to produce a source of anions of the desired compound. The negative ion packed is then extracted and shot and filtered through a mass gate. The selected anions then reverted first to neutral species, then to cations by a femtosecond pump laser and probe laser, respectively. The positive and neutral species are then detected and measured after separation. The cation signal is recorded at various time delays between pump and probe photons. This is done to gain information about neutral wavepacket propagation, and thus sheds light on the neutral species.