scholarly journals Ultrafast dynamics and scattering of protic ionic liquids induced by XFEL pulses

2021 ◽  
Vol 28 (5) ◽  
pp. 1296-1308 ◽  
Author(s):  
Kajwal Kumar Patra ◽  
Ibrahim Eliah Dawod ◽  
Andrew V. Martin ◽  
Tamar L. Greaves ◽  
Daniel Persson ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Form Factors ◽  
Atomic Motion ◽  
Organic Liquids ◽  
Ultrafast Dynamics ◽  
X Rays ◽  
Protic Ionic Liquids ◽  
Protic Ionic Liquid ◽  
X Ray ◽  
Scattering Signal

X-rays are routinely used for structural studies through scattering, and femtosecond X-ray lasers can probe ultrafast dynamics. We aim to capture the femtosecond dynamics of liquid samples using simulations and deconstruct the interplay of ionization and atomic motion within the X-ray laser pulse. This deconstruction is resolution dependent, as ionization influences the low momentum transfers through changes in scattering form factors, while atomic motion has a greater effect at high momentum transfers through loss of coherence. Our methodology uses a combination of classical molecular dynamics and plasma simulation on a protic ionic liquid to quantify the contributions to the scattering signal and how these evolve with time during the X-ray laser pulse. Our method is relevant for studies of organic liquids, biomolecules in solution or any low-Z materials at liquid densities that quickly turn into a plasma while probed with X-rays.

X-ray Scattering Factors of Ions in Crystals

1979 ◽  
Vol 34 (12) ◽  
pp. 1471-1481 ◽  
Author(s):  
P. C. Schmidt ◽  
Alarich Weiss
Keyword(s):  
Gaseous Phase ◽  
Form Factors ◽  
Negative Ions ◽  
X Rays ◽  
Charged Sphere ◽  
Sphere Model ◽  
X Ray ◽  
Hartree Fock ◽  
X Ray Scattering ◽  
Atomic Scattering

AbstractThe atomic scattering factors for X - Rays are given for the ions Li⊕, Be2⊕, B3⊕, C4⊕, N5⊕, N3⊖, O2⊖, F⊖, Na⊕, Mg2⊕, Al3⊕, S2⊖, Cl⊖, K⊕, Ca2⊕, Sc3⊕, Ti4⊕, V5⊕, Ni, Cu⊕, Zn2⊕, Ga3⊕, Se2⊖, Br⊖, Rb⊕, Sr2⊕, Y3⊕, Pd, Ag⊕, Cd2⊕, I⊖, Cs⊕, and Ba2⊕ in the crystal. The crystal potential is simulated by a hollow charged sphere (Watson sphere model). The Hartree-Fock-Roothaan-method was used for the calculation. The crystal field affects most strongly the atomic form factors of the negative ions, especially the twofold and threefold ionized negative ions, which are unstable in the gaseous phase.

LASER PULSE CIRCULATION SYSTEM FOR COMPACT MONOCHROMATIC TUNABLE HARD X-RAY SOURCE

2007 ◽  
Vol 22 (23) ◽  
pp. 4324-4332
Author(s):  
HARUYUKI OGINO ◽  
MENG DE ◽  
TOMOHIKO YAMAMOTO ◽  
FUMITO SAKAMOTO ◽  
KATSUHIRO DOBASHI ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Circulation System ◽  
X Rays ◽  
Electron Linear Accelerator ◽  
Yag Laser ◽  
X Ray ◽  
X Band ◽  
Rf Pulse ◽  
Under Construction ◽  
The University

We are construcing a laser electron Compton scattering monochromatic tunable hard X-ray source. It consists of the X-band (11.424 GHz) electron linear accelerator and Q-switch Nd : YAG laser. This work is a part of the JST (Japan Science and Technology Agency) project. The whole system is a part of the national project on the advanced compact medical accelerator development, hosted by NIRS (National Institute for Radiological Science). The University of Tokyo and KEK are working for the X-ray source. Main advantage of this X-ray source is monochromatic tunable hard X-rays (10-50keV) with the intensities of 108-109 photons/s. The table-top size X-ray source can generate dual energy monochromatic hard X-ray by turns and it takes about 40ms to chage the X-ray energy. It is calculated that the X-ray intensity is 107 photons/RF-pulse (108 photons/s in 10 pps) by the 35MeV electron and YAG laser (2J/pulse). The X-band beam line for the demonstration is under construction. We designed a laser pulse circulation system to increase the X-ray yield 10 times higer (up to 108 photons/RF-pulse, 109 photons/s). It can be proved that the laser total energy increases 10 times higher by the principle experiment with the lower energy laser (25mJ/pulse).

MULTI-BEAM COMPTON SCATTERING MONOCHROMATIC TUNABLE HARD X-RAY SOURCE

2007 ◽  
Vol 21 (03n04) ◽  
pp. 559-571 ◽  
Author(s):  
MITSURU UESAKA ◽  
FUMITO SAKAMOTO ◽  
ATSUSHI FUKASAWA ◽  
HARUYUKI OGINO ◽  
TOMOHIKO YAMAMOTO ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Compton Scattering ◽  
Optical Switch ◽  
Professional School ◽  
Circulation System ◽  
X Rays ◽  
Electron Linear Accelerator ◽  
Yag Laser ◽  
X Ray ◽  
X Band

Compton scattering hard X-ray source which consists of an X-band (11.424 GHz) electron linear accelerator and YAG laser is under construction at Nuclear Professional School, the University of Tokyo (UTNS). Monochromatic hard X-rays are required for variety of medical and biological applications. Our scheme of the hard X-ray source is to produce a monochromatic hard X-ray via collision between 35 MeV electron beam and 2.5 J/10 nsec Nd : YAG laser. In order to increase the efficiency of the X-ray yield, we adopt a laser pulse circulation system. In our case, the laser pulse circulation system can increase the X-ray intensity of up to 50 times. Main features of our scheme are to produce monochromatic tunable hard (10-40 keV) X-rays with the intensities of 108-109 photons/sec. In addition, X-ray energy can be changed with rapidly by 40 ms by introducing two different wavelength lasers (YAG fundamental (1064 nm), 2nd harmonic (532 nm)) and optical switch. This quick energy change is indispensable to living specimens and very difficult by a large SR light source and others. We designed a laser pulse circulation system to increase the X-ray yield 10 times higher (up to 108 photons/RF pulse, 109 photons/sec). It can be proved that the laser total increases 10 times higher by principle experiment with lower energy laser (25 mJ/pulse). Dual-energy X-ray CT and subtraction X-ray CT are available to determine 3D distribution of atomicc number density and electron density, and specified atomic distribution, respectively. Here, the construction status of the X-band beam line and the application plan of the hard X-ray will be reported.

Coherent and incoherent scattering of low-energy X-ray photons in the atomic region 13 ≤ Z ≤ 82

1996 ◽  
Vol 74 (1-2) ◽  
pp. 10-16 ◽  
Author(s):  
D. V. Rao ◽  
R. Cesareo ◽  
G. E. Gigante ◽  
D. V. Rao ◽  
G. E. Gigante
Keyword(s):  
Cross Sections ◽  
Detection System ◽  
Form Factors ◽  
Coherent Scattering ◽  
Incoherent Scattering ◽  
X Rays ◽  
Bremsstrahlung Radiation ◽  
X Ray ◽  
Scattering Cross ◽  
Scattering Cross Sections

Coherent- and incoherent-scattering cross sections for the elements Al, Cu, Y, In, Au, and Pb were measured using nearly monoenergetic unpolarized 35.86 and 39.96 keV X-ray beams with high-resolution Si (Li) detectors. Bremsstrahlung radiation from an X-ray tube was used to excite nearly monoenergetic X-rays in secondary targets. To improve the efficiency of the detection system the excitation source, detector, and the target assembly were placed in a vacuum chamber and a pressure of 10−2 mbar was maintained throughout the measurements. This system considerably reduced the background and scattering effects and improved the monochromacy. Experimental coherent-scattering cross sections are compared with the normalized integrated coherent-scattering cross sections calculated using the relativistic, nonrelativistic, and relativistic-modified form factors. Experimental incoherent-scattering cross sections are compared with the theoretical values, calculated using the nonrelativistic incoherent-scattering function. Good correspondence is observed between experimental and theoretical values in the given energy region.

scholarly journals Laser Larmor X-ray radiation from low-Z matter

1999 ◽  
Vol 17 (1) ◽  
pp. 45-58 ◽  
Author(s):  
YUTAKA UESHIMA ◽  
YASUAKI KISHIMOTO ◽  
AKIRA SASAKI ◽  
TOSHIKI TAJIMA
Keyword(s):  
Energy Spectrum ◽  
Laser Pulse ◽  
Electromagnetic Fields ◽  
Short Pulse ◽  
Intense Laser ◽  
X Rays ◽  
Bremsstrahlung Radiation ◽  
Pulse Laser Irradiation ◽  
X Ray ◽  
Short Pulse Laser

A relativistically intense short laser pulse can produce a large flux of X rays through the interaction with electrons that are driven by its intense electromagnetic fields. Apart from X rays from the high-Z matter irradiation by an intense laser, two main processes, Larmor and Bremsstrahlung radiation, are among the most significant mechanisms for X-ray emission from short-pulse laser irradiation on low-Z matter in the regime of relativistic intensities. We evaluate the power, energy spectrum, brilliance, polarization, and time structure of these X rays. We suggest a few methods that significantly enhance the power of Larmor X rays. Because of the peakedness in the energy spectrum of Larmor X rays, Larmor X rays have important applications.

scholarly journals Ultrafast Dynamics of a Nucleobase Analogue Illuminated by a Short Intense X-ray Free Electron Laser Pulse

2016 ◽  
Vol 6 (2) ◽  
Author(s):  
K. Nagaya ◽  
K. Motomura ◽  
E. Kukk ◽  
H. Fukuzawa ◽  
S. Wada ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Free Electron ◽  
Free Electron Laser ◽  
Ultrafast Dynamics ◽  
X Ray

Elemental Analysis of Stainless Steel Using Hard X-Ray Emission Arising from a High-Density Plasma Produced by an Intense Femtosecond KrF Laser Pulse

2002 ◽  
Vol 56 (9) ◽  
pp. 1161-1164 ◽  
Author(s):  
N. Takeyasu ◽  
Y. Hirakawa ◽  
T. Imasaka
Keyword(s):  
Stainless Steel ◽  
Laser Pulse ◽  
Emission Spectrum ◽  
Elemental Analysis ◽  
Single Photon ◽  
Continuum Emission ◽  
Stainless Steel Sample ◽  
X Rays ◽  
X Ray ◽  
Krf Laser

Characteristic hard X-rays emitted from a laser-produced plasma induced by focusing a femtosecond KrF laser pulse are employed for elemental analysis. The emission spectrum of the hard X-ray arising from a stainless steel sample is measured by means of a single-photon-counting X-ray detector equipped with a multichannel analyzer. The elemental analysis is carried out from the photon energy of the Kα line observed in the X-ray emission spectrum, and a calibration curve is constructed for Fe using stainless steel samples prepared at different concentrations (SUS-301, 310, and 316). A continuum band was overlapped on the sharp Kα lines in the X-ray spectrum, which made the assignment of the weak characteristic Kα lines arising from minor elements difficult. In order to suppress this undesirable emission, a prepulse technique was employed. The continuum emission was shifted toward lower energies, and, as a result, the characteristic Kα lines were more clearly observable. The potential advantages of the present approach are also discussed in this study.

MEDICAL APPLICATION OF MULTI-BEAM COMPTON SCATTERING MONOCHROMATIC TUNABLE HARD X-RAY SOURCE

2007 ◽  
Vol 22 (22) ◽  
pp. 3988-3999
Author(s):  
Mitsuru Uesaka ◽  
Katsuhiro Dobashi ◽  
Fumito Sakamoto ◽  
Atsushi Fukasawa ◽  
Haruyuki Ogino ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Compton Scattering ◽  
Optical Switch ◽  
Medical Application ◽  
Professional School ◽  
Circulation System ◽  
X Rays ◽  
Electron Linear Accelerator ◽  
X Ray ◽  
X Band

Compton scattering hard X-ray source which consists of an X-band (11.424 GHz) electron linear accelerator and YAG laser is under construction at Nuclear Professional School, the University of Tokyo. Monochromatic hard X-rays are required for variety of medical and biological applications. Our scheme of the hard X-ray source is to produce a monochromatic hard X-ray via collision between 35 MeV electron beam and 2.5 J/10 nsec Nd:YAG laser. In order to increase the efficiency of the X-ray yield, we adopt a laser pulse circulation system. In our case, the laser pulse circulation system can increase the X-ray intensity of up to 10 times. Main features of our scheme are to produce monochromatic tunable hard (10-40 keV) X-rays with the intensities of 108-109 photons/sec. In addition, X-ray energy can be changed with rapidly by 40 ms by introducing two different wavelength lasers (YAG fundamental (1064 nm), 2nd harmonic (532 nm)) and optical switch. This quick energy change is indispensable to living specimens and very difficult by a large SR light source and others. Dual-energy X-ray CT and subtraction X-ray CT are available to determine 3D distribution of atomic number density and electron density, and specified atomic distribution, respectively. Here, the construction status of the X-band beam line and the application plan of the hard X-ray are described and discussed.

scholarly journals Characterization of a bright, tunable, ultrafast Compton scattering X-ray source

2004 ◽  
Vol 22 (3) ◽  
pp. 221-244 ◽  
Author(s):  
F.V. HARTEMANN ◽  
A.M. TREMAINE ◽  
S.G. ANDERSON ◽  
C.P.J. BARTY ◽  
S.M. BETTS ◽  
...  
Keyword(s):  
Electron Beam ◽  
Laser Pulse ◽  
Compton Scattering ◽  
Electron Beams ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
X Rays ◽  
Full Width ◽  
Half Maximum ◽  
X Ray

The Compton scattering of a terawatt-class, femtosecond laser pulse by a high-brightness, relativistic electron beam has been demonstrated as a viable approach toward compact, tunable sources of bright, femtosecond, hard X-ray flashes. The main focus of this article is a detailed description of such a novel X-ray source, namely the PLEIADES (Picosecond Laser–Electron Inter-Action for the Dynamical Evaluation of Structures) facility at Lawrence Livermore National Laboratory. PLEIADES has produced first light at 70 keV, thus enabling critical applications, such as advanced backlighting for the National Ignition Facility andin situtime-resolved studies of high-Zmaterials. To date, the electron beam has been focused down to σx= σy= 27 μm rms, at 57 MeV, with 266 pC of charge, a relative energy spread of 0.2%, a normalized horizontal emittance of 3.5 mm·mrad, a normalized vertical emittance of 11 mm·mrad, and a duration of 3 ps rms. The compressed laser pulse energy at focus is 480 mJ, the pulse duration 54 fs Intensity Full Width at Half-Maximum (IFWHM), and the 1/e2radius 36 μm. Initial X rays produced by head-on collisions between the laser and electron beams at a repetition rate of 10 Hz were captured with a cooled CCD using a CsI scintillator; the peak photon energy was approximately 78 keV, and the observed angular distribution was found to agree very well with three-dimensional codes. The current X-ray dose is 3 × 106photons per pulse, and the inferred peak brightness exceeds 1015photons/(mm2× mrad2× s × 0.1% bandwidth). Spectral measurements using calibrated foils of variable thickness are consistent with theory. Measurements of the X-ray dose as a function of the delay between the laser and electron beams show a 24-ps full width at half maximum (FWHM) window, as predicted by theory, in contrast with a measured timing jitter of 1.2 ps, which contributes to the stability of the source. In addition,K-edge radiographs of a Ta foil obtained at different electron beam energies clearly demonstrate the γ2-tunability of the source and show very good agreement with the theoretical divergence-angle dependence of the X-ray spectrum. Finally, electron bunch shortening experiments using velocity compression have also been performed and durations as short as 300 fs rms have been observed using coherent transition radiation; the corresponding inferred peak X-ray flux approaches 1019photons/s.

scholarly journals Study of uniformity of elongated plasma channels formed in gas puff targets using extreme ultraviolet and soft X-ray radiation

2015 ◽  
Vol 33 (2) ◽  
pp. 293-298 ◽  
Author(s):  
P.W. Wachulak ◽  
A. Bartnik ◽  
R. Jarocki ◽  
T. Fok ◽  
Ł. Węgrzyński ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Pulse Energy ◽  
Laser Pulse Energy ◽  
Extreme Ultraviolet ◽  
Laser Pulses ◽  
Pinhole Camera ◽  
Helium Plasma ◽  
X Rays ◽  
X Ray ◽  
Plasma Channels

AbstractThe results of formation of elongated krypton/helium plasma channels are presented. Two laser pulses were used: one to produce plasma channels and the second one for conversion to soft X rays. The soft X-ray radiation was in turn used for backlighting the channels and their visualization. The study of their formation and uniformity was performed using a combination of soft X-ray shadowgraphy and pinhole camera imaging. The plasma channels, with various lengths and various densities, were visualized and the results of their characterization are presented. Using moderate laser pulse energy quite uniform channels, up to 9 mm in length, were demonstrated.

Sign in / Sign up

Export Citation Format

Share Document