Bulletin of the American Physical Society
50th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics APS Meeting
Volume 64, Number 4
Monday–Friday, May 27–31, 2019; Milwaukee, Wisconsin
Session Q03: Ultrafast or High Intensity Light Sources |
Hide Abstracts |
Chair: Enam Chowdhury, Ohio State University Room: Wisconsin Center 101CD |
Thursday, May 30, 2019 2:00PM - 2:12PM |
Q03.00001: Few-cycle radially polarized pulses generation Chunmei Zhang, Fanqi Kong, Hugo Larocque, Ebrahim Karimi, Paul Corkum Vector beams have broad applications and extending them to the few-cycle regime will influence many fields. We experimentally demonstrated the compression of a radially polarized vector beam in the same way that we compress Gaussian beams using a gas filled hollow-core fiber. The pulses maintain their radially polarized nature. It is feasible, using only well-developed methods, to reach focused intensities of \textasciitilde 10$^{\mathrm{19}}$ W/cm$^{\mathrm{2}}$ where the field strength in all three dimensions reach relativistic intensities. Using solid or gas as a nonlinear medium, it will be possible to produce radially polarized harmonics with a curved wavefront that will reach wavelength scale focal spots compared to Gaussian beams, thus opening a route towards VUV microscopy. [Preview Abstract] |
Thursday, May 30, 2019 2:12PM - 2:24PM |
Q03.00002: Extreme Light Compression Jonathan Wheeler, Gerard Mourou, Toshiki Tajima A fundamental limit for the volume in which a given pulse energy achieves the maximum intensity is defined by its wavelength and is called the $\lambda^{3}$ regime. In applying this limit to a Petawatt system, one finds the capability to achieve maximum intensities just surpassing the ultra-relativistic threshold ($10^{24}$ W/cm$^{2}$) where the ponderomotive energy becomes comparable to the proton rest mass. To go beyond this toward the Schwinger limit ($10^{29}$ W/cm$^{2}$) is difficult due to challenges in accommodating the required energy. It is likely that the future will bring a plateau in the peak intensity with little gain in the achievable level unless a dramatic change is introduced. Considering the lambda-cubed limit also illuminates a solution: a shift to shorter wavelengths. The efficient production of a single-cycled, high energy laser pulse enables conversion through relativistic compression into a sub-femtosecond X-ray laser pulse. This is an efficient and innovative way to ascend to exawatt (EW) and zeptosecond (zs) science. Application of these High Field X-rays (HFX) in topics such as imaging, particle acceleration, and QED studies inspires the motivation for a concerted program to produce and employ such sources as the next stage in high intensity science. [Preview Abstract] |
Thursday, May 30, 2019 2:24PM - 2:36PM |
Q03.00003: Using high-field ionization for laser intensity calibration Marcelo Ciappina, Sergey Popruzhenko, Sergei Bulanov, Todd Ditmire, Georg Korn, Stefan Weber We present an approach for direct measurement of ultrahigh laser intensities in the range $10^{20}-10^{24}$ W/cm$^2$. The method is based on the use of multiple sequential tunneling ionization of heavy atoms with adequately high ionization potentials. We show that, due to the highly nonlinear dependence of tunneling ionization rates on the electromagnetic field strength, an off-set in the charge distribution of ions appears to be clearly sensitive to the peak value of intensity in the laser focus. Based on the tunnel-ionization mechanism, a simple analytic theory helps estimating the maximal charge state produced at a given laser intensity Our theory also allows calculating qualitatively a distribution in charge states generated in different zones of the laser focus. These qualitative predictions are in excellent agreement with numerical simulations of the tunneling cascades, developed in the interaction of a short tightly focused laser pulse with low-density noble gas targets. The method could be particularly useful and of instrumental demand in view of the expected commissioning of several new laser facilities, capable of delivering ultra-powerful light pulses in the above mentioned domain of intensities. [Preview Abstract] |
Thursday, May 30, 2019 2:36PM - 2:48PM |
Q03.00004: Relativistic Thomson scattering: a tool for pulse diagnostics and exploring inner-shell dynamics Calvin He, Wendell T. Hill, III, Andrew Longman, Robert Fedosejevs, Luis Roso, José A. Pérez-Hernández, Massimo de Marco, Giancarlo Gatti The new LaserNetUS together with several international facilities offering extreme pulse conditions have placed the intense-field and ultrafast communities on the cusp of opportunities to address our thirst for novel physics. The much-anticipated features (e.g., intensities at 10$^{23}$ W/cm$^2$ and beyond, subfemtosecond pulse durations, high rep rates) offer several channels through which to explore a host of new phenomena from inner-shell ultrafast dynamics to new tests of QED, and perhaps the Standard Model. These opportunities come with a cost -- the need to develop unique tools both to characterize the focused laser pulses at full energy and to capture the new physics. One promising tool, which was suggested about 50 years ago, is relativistic Thomson scattering (RTS), a low-energy ($\hbar \omega << m_e c^2$), multiphoton analogue of Compton scattering. Frequency and angular shifts of RTS relative to the laser frequency and propagation direction, respectively, are intimately linked to the pulse intensity, the electron insertion energy and the electron density. Recently, we explored the utility of RTS as an intensity gauge. The results of that experiment will be discussed along with simulations that reveal possibilities for investigating inner-shell dynamics. [Preview Abstract] |
Thursday, May 30, 2019 2:48PM - 3:00PM |
Q03.00005: MeV Photoelectron Spectrometer for Ultraintense Laser Interactions with Atoms and Molecules Barry Walker, Siyu Luo, Pat Grugan, Zach Germain, Zahide Demircioglu, Amylia Hoos, Rachael McIntyre, Yi Ji Spectroscopy techniques such as time-of-flight (TOF), velocity map imaging (VMI), and cold target recoil ion momentum spectroscopy (COLTRIMS) revolutionized laser matter interaction measurements. These traditional laser-matter spectroscopy techniques fail to accurately analyze photoelectrons and ions from ultrahigh intensity studies with terawatt and petawatt laser systems. At 10$^{19}$ W/cm$^2$ the interaction of ultraintense lasers with atoms and molecules creates photoelectrons with energies of 10$^6$ eV, well beyond the $\sim100$ eV limit of conventional apparatus. Quantifying the products from ultrahigh intensity lasers requires a new generation of spectrometers. We present a magnetic deflection, photoelectron spectrometer for ultrahigh intensity laser interactions with atoms and molecules in the single atom / molecule limit. The specifications included a range of energies from 20 keV to 2 MeV, an angular resolution of 2$^\circ$, an adjustable measurement angle within a solid angle of $\sim 2 \pi$ steradian, and a noise floor of order $10^{-1}$ events/(shot-Torr-keV). The spectrometer fabrication and calibration with beta decay sources will be presented as well as example photoelectron spectra for argon and chloromethane over the energy range from 20 keV to 2MeV. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700