THE PHYSICS LASER LAB

RESEARCH IN ATOMIC MOLECULAR aND OPTICAL PHYSICS(AMO) AND CHEMICAL PHYSICS AT NORTH CAROLINA A&T STATE UNIVERSITY
 

PI: Solomon Bililign, Ph.D. Professor of Physics
Research associate,Dr. Nayana Vaval (2001-2002) Dr. Robert Gdanitz(2002-2005)
  1. Benjamin McCarter (Graduate Student, Graduated in May 98)
  2. Niel Crews (not current)
  3. Tito Robinson (Graduated in May 2000)
  4. Michael Kutz (Graduated in May 1999)
  5. Luke Ekkizogloy (high school senior,Lee County High School, Leesburg,GA)
  6. Dr. Dereje Siefu (Visiting Assistant Professor, Morgan State University)
  7. Mr. John Brown (Visiting member, Science Teacher, Dudley High school, Greensboro, NC)
  8. Brian Hattaway(graduate Student)Now at University of Connecticut
  9. Jarreas Underwood (Graduate Student) Graduated
  10. T. Swindell (Graduate) Now at University of Georgea
  11. B. Barker (graduate)
  12. Ibrahima Ibou (Undergraduate) Current
  13. L. Perry (Undergraduate)
  14. Wandylis Vargas Colegio San Benito, Puerto Rico (Current NASA-SHARP student)
  15. Sewyalew Taddele (Undergraduate) Current
  16. Vivek komaiagiri (Graduate student) Current
  17. Natanael B. Semmineh (Graduate student) Current
  18. Kevin Wedderbur (Graduate Student) Current

Bililign's Research Group
(Left to right: L. Perry, W. Vergas,T. Swindell,R. Gdanitz, Brian Hattaway, Ibrahima Ibou, and Solomon Bililign)

Brian and Kevin in Marseillie.



The Laser Lab
 
Experimental Research 
NSF-MRI:0317836: Instrumentation award (2003-2005)
PI: Bililign, CO-PI's: L. Duffy (UNCG) and J. Harp NCA&T
   
REFLECTRON Time of Flight Mass Spectrometer (RTOF-MS) with Effusion Cell and a Leopard PS laser:
Reflectron Time of Flight Spectrometer: Photoionization source featuring delayed extraction flight tube and ion optics including integrated vertical and horizontal deflectors for guiding ions through the spectrometer.



The RTOF-MS

It also features dual detection: dual micro-channel plate detectors located at the linear end of the spectrometer and at the reflectron end of the spectrometer, floating anode, allowing detection of either positive or negative ions. It has computer controlled power supplies, ion mirror and deceleration; flight tube, detectors, deflectors and ion lens. The flight chamber will be horizontally mounted on metal frame with turbomolecular pump ( 300 l/s minimum) with controller and backing pump for main chamber, with Granville-Phillip micro-ion module ion gauge, and Pirani gauge. Under the conditions of electron impact ionization of room temperature gases, the mass resolution is about 2000 m/Dm (FWHM). When operated in linear mode, only molecular cluster ions are obtained. However the reflectron mode, which includes reversal of ion flow direction before analysis, increases the flight path of ions allowing analysis of fragments of parent molecules. The fragmentation pattern of a single species within a mixture can be analyzed. The ion mirror has a dispersion- correcting lensing providing a nearly perfect transmission of ions.
The Ion Source Chamber
The ionization chamber with source mounted on removable flange, water and electrical feed-through for source on the flange, a gate valve for isolating ion source chamber from sample chamber, and manual shutter to block the effusive beam when data is not being collected. The pulsed supersonic valve includes a valve capable of providing maximum flow at approximately

 

The new lab with the Pico second laser
  a 55 microsecond pulse at 10 Hz repetition rate or shorter, power supply with computer controlled external triggering and shielded cables. Modification to MALDI system to be accomplished at a latter time which requires modification of associated power supplies.
Sample Chamber
Effusion cell chamber, including isolation gate valve to isolate the turbomolecular pump from the chamber. Turbomolecular pump with controller and backing pump, mechanical roughing pump with isolation valve, vent valve, Granville-Phillips Micro-Ion Module ion gauge and Pirani gauge Kundsen Cell with 10 cc capacity and water cooling, power supply and PID temperature controller.

Sample Loading
Motorized vertical positioning system. Hinged access door.
Data Acquisition
TDC or 8-bit digitizer, preamp, and customized software.
NSF CHE- #9733744 : CAREER AWARD (1998-2002)
The CAREER proposal "Effects or Electronic Orbital Alignment in Laser Induced Reactions of Metal-H2 and Metal-CH4" has been funded (starting March 1,)1998) by The National Science Foundation. This helped the establishment of a state-of-the-art Laser lab for conducting research in laser induced reactions of small molecules. The principal goal of this research has been to study the effects of metal atom electronic orbital alignment in the reaction dynamics and energy transfer of MH2, and MCH4 (M = Li, Zn) collision complexes. The metal atoms were excited to different electronic states within the complex using a pump laser, and either reaction products were probed using a second probe laser or fluorescence from excited states of the metal atom was observed following pump laser excitation.
NSF CHE-0131115 (2002-2005)
The NSF grant has been renewed for three more years starting March 2002. The research will involve quenching of excited states of Alkali atoms (Li, Na) by alkene and Alkane Hydrocarbons and Nitrogen. Both kinetic and reaction dynamics studies will be conducted.The project addresses two issues. The first is molecular reaction dynamics. The goal is to understand how reagent molecules approach, collide, exchange energy, and finally separate into products We also try to understand how the energy put into a reactant molecule redistribute among the different degrees of freedom and how fast this happens Further more we are interested in the detailed nuclear motions that chart the reaction The second issue deals with C-H activation by metal atoms, an issue considered as one of the most important reactions in chemistry.
 
Theoretical Research
 
NSF- CHE-9526197 RUI (1996-1999)
The grant allowed the purchase of two IBM RS/6000 work stations (Model 590 and Model 3AT) and a new SUN ULTRA 60 workstation for carrying out Ab initio electronic structure calculations. We also have access to the supercomputing facilities (Cray) at the North Carolina Super Computer Center.

NSF/ DUKE CCR-0086013 (2000-2005)
Current activities are supported by NSF-ITR grant which include developing model potentials for Metal-rare gas interactions, calculations to study structure and stability of metal clusters, and calculation of potential energy surfaces of systems investigated in our labs. The group called the Biogeometry group is an interdisciplinary collaborative project among researchers from Duke University, Stanford University, University of North Carolina Chapel Hill, and North Carolina A&T University whose goal is the development of new computational techniques and paradigms for representing, storing, searching, simulating, analyzing, and visualizing biological structures.

For Further Information.
Contact Dr. Solomon Bililign
phone 336-334-7646
e-mail: mailto:bililign@ncat.edu