Skip to main content
News   |   Events   |   Safety   |   CHESS-U>   |   InSitμ   |   MacCHESS   |   CLASSE

X-RAY RUNS: Apply for Beamtime

2017  March 15 - April 24

2017  May 17 - June 29
2017  BTR deadline: 04/17/17

2017  October 11 - December 21
2017  Proposal deadline: 08/01/17
2017  BTR deadline: 09/10/17

March 18, 2005

Sol Gruner, Professor of Physics, Director of CHESS
Cornell Tree-Ring Laboratory and Professor, Department of Cornell University

_______________________________________________

March 11, 2005

Elaine Seddon, Professor
CCLRC Daresbury Laboratory, U.K.

"4GLS Project"

_______________________________________________

March 4, 2005

Peter Busch, Post Doctoral Associate
Materials Science & Engineering, Cornell University

"Grazing Incidence Small Angle X-ray Scattering (GISAXS) on thin Block Copolymer Films - A Comparison between Experiment and Theory"

Abstract:  The talk gives an introduction of the basic principles and specific features of GISAXS on thin films of diblock copolymers.  Characteristic scattering patters obtained at CHESS D-line will be presented and discussed in the framework of the distorted Wave Born approximation (DWBA-theory).

_______________________________________________

February 25, 2005

Kurt Andresen, Graduate Student
A&EP, Cornell University

_______________________________________________

February 18, 2005

Arthur Woll, Senior Research Associate
CHESS, Cornell University

_______________________________________________

February 11, 2005

Ken Finkelstein, Senior Research Associate
CHESS, Cornell University

"Mixing X-rays and Laser Light: a novel recipe, but does it taste good?"

Abstract:  Dr. Finkelstein hopes to explain how x-ray diffraction might be modulated using a fast laser. When x-ray energy is tuned close to an atomic absorption edge the resonating atom can act as a non-spherical scatterer, and this can produce diffraction peaks at reciprocal space positions where crystal symmetry forbids Bragg reflection. This so-called "resonant diffraction" is sensitive to the local symmetry at the resonating atom.  Collins and co-workers (PRB 68, 064110 (2003)) observed what they believe is a thermal-motion-induced deformation causing a dramatic change in resonant diffraction. In the same type crystal (zinc oxide) Yee and co-workers (J. of the Korean Physical Soc. 42, S157 (2003)) used a femtosecond pulse laser to generate and study a coherent optical phonon; a well defined oscillatory lattice distortion driven by the laser electric field.  We will discuss how these ideas might be combined into an experiment to explore laser driven x-ray diffraction.

_______________________________________________

February 4, 2005

George Hoffstaetter, Professor of Physics
LEPP, Cornell University

"Damping Wigglers for Storage Rings"

Professor Hofstaetter will discuss the different projects that include damping wigglers.  These projects will be described, illustrating the different purposes for which such devices can be used. The beneficial, as well as, the detrimental beam-dynamics effects that damping wigglers introduce will be described on an introductory level.

_______________________________________________

January 28, 2005

Donald Bilderback, Associate Director
CHESS, Cornell University

"Lensless Imaging of Magnetic Nanostructures by X-ray Spectro-Holography"

Abstract:  Professor Bilderback will discuss this paper published December 16, 2004 in Nature, Vol. 432, pgs 885-888.  “Our knowledge of the structure of matter is largely based on X-ray diffraction studies of periodic structures and the successful transformation (inversion) of the diffraction patterns into real-space atomic maps.  But the determination of non-period nanoscale structures by X-rays is much more difficult.  Inversion of the measured diffuse X-ray intensity patterns suffers from the intrinsic loss of phase information, and direct imaging methods are limited in resolution by the available X-ray optics.  Here we will demonstrate a versatile technique for imaging nanostructures, based on the use of resonantly tuned soft X-rays for scattering contrast and the direct Fourier inversion of a holographically formed interference pattern". (S. Eisebitt, J. Luning, W.F. Schlotter, M. Lorgen, O. Hellwig, W. Eberhards & J. Stohr, Nature, Vol. 432, 12/16/04)

_______________________________________________

January 21, 2005

Aaron Fleet, Ph.d, Candidate
School of Applied Physics, Cornell University

"Observed Effects of a Changing Step-Edge Density on Thin-Film Growth Dynamics"

Abstract:  “Researchers have achieved excellent practical proficiency in the growth of high quality complex oxide thin films by Pulsed Laser Deposition (PLD).  These materials exhibit a range of functional properties that may be incorporated into future microelectronics, storage and energy applications. However, few studies have advanced the fundamental understanding of plume-substrate interactions during the PLD process.  We have found evidence suggesting that energetic species in the plume initiate rapid smoothing processes upon arrival at the substrate….”  Aaron Fleet, Darren Dale, Y. Suzuki, J.D. Brock

_______________________________________________

January 7, 2005

Xianghui Xiao, Post Doctoral
CHESS, Cornell University

"Distorted Object Approach to Fresnel Diffraction and Phasing of Near-Field Holographic Images"

_______________________________________________