BES - SLAC Group/Department Public Websites - Stanford University

More documents

Recommendations

Info

FYO7 SLAC S CIENCE AND T ECHNOLOGY S ELF E VALUATION and the nonlinearity can be tuned via the direct current voltage applied to the tip. Numerical simulations of this system show that electron emission takes place within less than one optical period of the exciting laser pulse, so that an 8 fs 800 nm laser pulse is capable of producing a single electron pulse of less than 1 fs duration. Furthermore, we find that the carrier envelope phase dependence of the emission process is smaller than 0.1% for an 8 fs pulse but is steeply increasing with decreasing laser pulse duration. Rotational Wave Packets Probed By High Harmonic Generation, B. K. McFarland, Bulletin of the American Physical Society, 52 (7), J6.00010 (2007) We prepare an aligned distribution of cold N2 molecules by the interaction with an intense nonresonant fs laser pulse (pump pulse). The distribution is probed by HHG using a time delayed probe pulse. The high harmonics show an enhancement if the molecules are aligned with the probe pulse polarization and suppression if the molecules are aligned orthogonal to the polarization. We observe a first alignment 300 fs after the pump pulse. For longer time delays, we observe fractional and full revivals (the later at about 8 ps) of the rotational wave packet. We measure the relative phase of high harmonics from N2 and Ar at the half revival for N2, with a phase jump at the 23 rd harmonic. The alignment contrast and phase relation among the high harmonics is discussed in the context of the two-center model. Phonon Dispersion Relations and Softening in Photoexcited Bismuth From First Principles, E. D. Murray, S. Fahy, D. Prendergast, T. Ogitsu, D. M. Fritz and D. A. Reis, Phys. Rev. B, 75, 184301 (2007) The phonon dispersion relations for equilibrium and photoexcited bismuth are calculated from first principles density-functional perturbation theory. The results are in agreement with available experimental data, providing justification to the assumptions used in the calculations. This advances our understanding of the interplay between the electronic and ionic components that comprise a solid. Magnetism From Fundamentals to Nanoscale Dynamics, H.C. Siegmann and J. Stöhr, Springer Series in Solid-State Sciences , Vol. 152, 2006, XVII, 820 p. 325 illus., Hardcover, ISBN: 978-3-540- 30282-7 The book covers both the classical and quantum mechanical aspects of magnetism and novel experimental techniques. Perhaps uniquely, it discusses spin transport and ultrafast magnetization dynamics phenomena associated with atomically and spin engineered nanostructures against the backdrop of spintronics and magnetic storage and memory applications. Synchronized and Configurable Source of Electrical Pulses for X-Ray Pump Probe Experiments, J. P. Strachan, V. Chembrolu, X. W. Wu, T. Tyliszczak and Y. Acremann, Rev. Sci. Instrum., 78, 054703 (2007) The pulse generator described here is used to excite magnetic nanostructures with current pulses. Having an excitation system which can match the high repetition rate of a synchrotron allows for utilization of the full x-ray flux and is needed in experiments that require a large photon flux. The fast rise times allow for picosecond time resolution in pump-probe experiments. N OTEWORTHY PRACTICES Timing System for Time Resolved Scanning X-Ray Microscopy Currently, the scanning x-ray setup that we created is used by several groups in the magnetism community using the scanning transmission x-ray microscope in Berkeley. Electro-Optic Bunch Length Monitor and Timing Diagnostic The bunch length monitor and timing diagnostic that PULSE developed was duplicated at the FLASH FEL in Hamburg and will be implemented at the LCLS. P A G E 1 8 F I N A L
FYO7 SLAC S CIENCE AND T ECHNOLOGY S ELF E VALUATION Terahertz Pulses Because of this simplicity, we believe this technique will become part of the arsenal of time-resolved techniques that will be used at the LCLS, for performing both THz pump - x-ray probe and x-ray Pump - THz probe experiments. Attosecond Pulses In the HHG/attosecond lab, we are studying the influence of the molecular electronic orbital symmetry on the emitted strong field harmonics. We have implemented new phase measure approaches by using a reference oscillator in the HHG process, and have also developed new simulations of the HHG process. These results will have a significant impact on the electron orbital imaging schemes using high harmonics and will be an elegant way to shape attosecond pulses in amplitude and phase during their generation. O PPORTUNITIES FOR I MPROVEMENT Timing System for Time Resolved Scanning X-Ray Microscopy We started to develop an improved version of the x-ray timing system that will offer the possibility to be used for many experiments by the time resolved x-ray community. Electro-Optic Bunch Length Monitor and Timing Diagnostic This EO bunch length monitor makes possible a wide range of repetitive measurements with timeresolution limited by the pump and probe durations instead of the intrinsic jitter between pump and probe. Relative timing information from spatially-resolved EO measurements could be extended to a resolution of order 5 fs, matching the projected performance of future X-Ray FELs (XFELs) into the foreseeable future. Coherent Imaging The coherent imaging experiments at FLASH will greatly assist in the development and success of the LCLS program, providing access to similar x-ray intensities at soft x-ray wavelengths. Attosecond Pulses The attosecond pulse project will have a significant impact on future attosecond operational modes at the LCLS, associated with enhanced SASE and the use of carrier-envelope phase stabilized lasers to control the LCLS pulse shape. Objective 1.2 Leadership in Science and Technology PULSE members are international leaders, as illustrated in the following list of major FY07 local, regional and international advisory positions. Bucksbaum, Philip Chair of the Department of Photon Sciences, SLAC Chair, AMO 2010, the National Academy of Sciences decadal study of AMO physics Editor of the Virtual Journal of Ultrafast Science Divisional Associate Editor of Physical Review Letters Chair, AMO Screening Panel, National Academy of Sciences Member of the National Academy of Sciences Board on Physics and Astronomy Member of the Board of Directors of the Optical Society of America Member of the BESAC Grand Challenges Committee Member of the Advisory Committee of Physics Today Member of the Science Advisory Committee for the LCLS Member of the External Advisory Board for the Advanced Light Source at Berkeley Member of the Physics Today Advisory Committee for the American Institute of Physics Member of the External Advisory Board for the NSF Extreme Ultraviolet (EUV) Engineering Research Center, Colorado State University F I N A L P A G E 1 9
Page 1: FY07 Self-Evaluation Contractor Per
Page 4 and 5: HEP ...............................
Page 6 and 7: FYO7 SLAC S CIENCE AND T ECHNOLOGY
Page 8 and 9: BES FYO7 SLAC S CIENCE AND T ECHNOL
Page 36 and 37: F ▪ BABAR at PEP-II FYO7 SLAC S C
Page 40 and 41: SLAC. GLAST FYO7 SLAC S CIENCE AND
Page 42 and 43: SNAP FYO7 SLAC S CIENCE AND T ECHNO
Page 72 and 73:
FYO7 SLAC S CIENCE AND T ECHNOLOGY
Page 74 and 75:
BES FYO7 SLAC S CIENCE AND T ECHNOL
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
BES FYO7 SLAC S CIENCE AND T ECHNOL
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
show all

BES - SLAC Group/Department Public Websites - Stanford University

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?