News and Events
group meetings:
  high energy group: Tuesday 3:30pm RLM 2.216    
surface group: Monday 1pm RLM 2.216

Terawatt Lab Renovation

High-intensity research in Mike Downer’s group is conducted in the 1200 square foot Room 2.408 of Robert Lee Moore Hall on the UT campus.   Since the mid-1990s this lab housed a home-built 5 TW Ti:S chirped-pulse amplification system synchronized to a 1J, 400 ps Nd:YAG laser-amplifier, and more recently a 3 mJ, 100 fs, 870 nm chirped pulse Raman amplifier {link to F. Grigsby’s paper under “Publications”}. This laboratory routinely experienced temperature swings of  ±10 F, and controlled particulates with a home-built HEPA filter system without monitors.  State-of-the-art terawatt lasers, however, require much stricter environmental standards.  Accordingly, we developed and implemented plans to upgrade this laboratory to a clean room along the following time table:
May 2006: University of Texas committed $700K funds to clean room construction.  
    
Summer&Fall 2006: technical planning of clean room
April 2, 2007: University of Texas issued formal bid invitation. 
April 23, 2007: Contract awarded to M. W. Morgan Construction, Inc. 
June 2007: Ti:S system decommissioned, Nd:YAG and Raman-shifted subsystems stored, and construction began on a class 100,000 clean room.
October 2007: Clean room completed.  Tested and certified at class 10,000, exceeding specifications. Visit our Clean Room construction photo gallery. 

 

The major specifications of the new clean room are:

  1. 1200 sq. ft. total, including 9 x9 ft gown room,
  2. 16 x 12 ft mechanical room outside clean room housing laser power supplies & air-handling unit
  3. Class 10,000 (NF EN ISO 14644-1:1999 Class 8);
  4. 12 air changes per minute Temperature set point 69F ± 1 F tolerance
  5. Humidity control 50% RH max.

In February 2008, a new commercial 45 TW, 25 fs Ti:S chirped-pulse amplification system manufactured by THALES Laser (Model Alpha 10/XS 45 TW) will be installed in the clean room, and will be the principal laser system for our high-intensity research. The 1J, 400 ps Nd:YAG laser-amplifier and 10 mJ, 100 fs, 870 nm chirped pulse Raman amplifier subsystems will be re-synchronized with the new Ti:S system to constitute the University of Texas Tri-Color Terawatt (UT3) system

 

Calendar


January 2008

International Workshop on Plasma Shocks and Particle Acceleration
Osaka, Japan Jan. 24-26, 2008

This interdisciplinary workshop assembled astrophysicists and laboratory laser-plasma physicists to explore possible connections between the production of ultra-high energy cosmic rays [1] and laser-plasma-based acceleration of charged particles in the laboratory [2].  Professor M. Hoshino (U. Tokyo) reviewed the field of cosmic ray astrophysics.  Cosmic rays with energies up to about e15 eV are thought to be generated by supernova shocks.  Energies above e15 eV are believed to originate in active galactic nuclei or gamma ray bursts at cosmological distances.  Energies above 6e19 eV have particularly intrigued astrophysicists because the mechanism of their production is not understood, and because the so-called GZK (Greisen-Zatsepin-Kuzmin) cutoff predicts that protons with these energies would lose energy by creating pions in collisions with low-energy photons of the cosmic microwave background, and thus must originate relatively close to our galaxy.  In 2002, Chen et al. proposed that a mechanism akin to plasma wakefield acceleration, driven by cosmic magneto waves might be responsible for ultra-high energy cosmic rays [3].  Prof. R. Sydora (U. Alberta, Canada) presented simulations of magneto-wave-induced plasma wakefield acceleration that lend credibility to this proposal, and suggested laboratory experiments to explore it.

The workshop featured an active exchange of ideas between these two groups of physicists.  At the workshop, Prof. Mike Downer gave an invited presentation entitled “Holographic snapshots of laser wakefields,” based in part on the Ph.D. project of former student Nicholas Matlis [4], and suggested that this imaging technique could play an important role in future experiments designed to explore the mechanism of astrophysical wakefields.  

[1] Bertram Schwarzschild, “The highest energy cosmic rays appear to come from nearby active galactic nuclei,” Search & Discovery section of Physics Today 61, 16 (January 2008) and references therein. 

[2] C. Joshi and T. Katsouleas, “Plasma accelerators at the energy frontier and on tabletops,” Physics Today 56, 47 (June 2003). 

[3] P. Chen, T. Tajima, Y. Takahashi, “Plasma wakefield acceleration for ultra-high energy cosmic rays,” Phys. Rev. Lett. 89, 161101 (2002). 

[4] N. H. Matlis et al., “Snapshots of laser wakefields,” Nature Physics, 2, 749-753 (2006). 

 
 		  

July 2007

  
15th - 20th

Conference on Optics of Surfaces and Interfaces (OSI) VII conference in Alta, Wyoming
   
The elucidation of the dynamical interaction of atoms and molecule in various charged or excited states with surfaces is a major scientific challenge at the present time. Surface and interface dynamics also form the basis for understanding a number of technologically important issues, including surface and thin film growth, chemical reactions at surfaces and surface phase transitions. Optical spectroscopy of surfaces and interfaces comprises a variety of linear and non-linear optical techniques that have the potential to study optical, electronic, magnetic and vibronic properties at surfaces and interfaces.