scholarly journals An effect of the target position relative to the laser focus on X-ray emission from the laser plasma

1992 ◽  
Vol 10 (4) ◽  
pp. 743-751 ◽  
Author(s):  
M. Chvojka ◽  
B. Králiková ◽  
E. Krouský ◽  
L. Láska ◽  
K. Maŝek ◽  
...  
Keyword(s):  
Laser Plasma ◽  
Laser System ◽  
Broad Band ◽  
Plasma Temperature ◽  
Target Position ◽  
Resonant Line ◽  
X Ray ◽  
Laser Focus ◽  
Foil Target ◽  
Band Spectra

The first harmonics beam generated by an iodine laser system was focused by an f/2 optics on an Al foil target. The X-ray output from the laser plasma both in the line and broad-band spectra was registered over an interval around the “ideal” focus. It was found that the maximum X-ray power is not obtained in the focus itself but for a somewhat larger focal spot outside the focus. To explain this phenomena, temperature and density measurements were in addition made. The plasma temperature evaluated from both the line (He-like Al XII resonant line and j, k, l satellites) and broad-band spectra (two foil method) was also measured and found to be largely constant in the vicinity of the focus. The line and broad-band temperatures differ, the broad-band temperature being about 25% higher. The electron density was equally determined using an intercombination line.

scholarly journals A stochastic propagation model to the energy dependent rapid temporal behaviour of Cygnus X-1 as observed by AstroSat in the hard state

2019 ◽  
Vol 486 (2) ◽  
pp. 2964-2975 ◽  
Author(s):  
Bari Maqbool ◽  
Sneha Prakash Mudambi ◽  
R Misra ◽  
J S Yadav ◽  
S B Gudennavar ◽  
...  
Keyword(s):  
Time Lag ◽  
Broad Band ◽  
Propagation Model ◽  
Large Area ◽  
Temporal Behaviour ◽  
X Ray ◽  
Single Temperature ◽  
Hard State ◽  
Band Spectra ◽  
Energy Dependent

Abstract We report the results from analysis of six observations of Cygnus X-1 by Large Area X-ray Proportional Counter (LAXPC) and Soft X-ray Telescope (SXT) onboard AstroSat, when the source was in the hard spectral state as revealed by the broad-band spectra. The spectra obtained from all the observations can be described by a single-temperature Comptonizing region with disc and reflection components. The event mode data from LAXPC provides unprecedented energy dependent fractional root mean square (rms) and time-lag at different frequencies which we fit with empirical functions. We invoke a fluctuation propagation model for a simple geometry of a truncated disc with a hot inner region. Unlike other propagation models, the hard X-ray emission (>4 keV) is assumed to be from the hot inner disc by a single-temperature thermal Comptonization process. The fluctuations first cause a variation in the temperature of the truncated disc and then the temperature of the inner disc after a frequency dependent time delay. We find that the model can explain the energy dependent rms and time-lag at different frequencies.

Coded aperture x-ray imaging of high power laser-plasma interactions on the Vulcan Laser System

2018 ◽  
Author(s):  
Robert I. Heathcote ◽  
Nicola Booth ◽  
Robert J. Clarke ◽  
Asha Anderson-Asubonteng ◽  
Matthew P. Selwood ◽  
...  
Keyword(s):  
High Power ◽  
Laser Plasma ◽  
Laser System ◽  
Coded Aperture ◽  
High Power Laser ◽  
Power Laser ◽  
Plasma Interactions ◽  
X Ray ◽  
Laser Plasma Interactions ◽  
X Ray Imaging

BeppoSAX observations of the massive X-ray pulsar Cen X-3: Broad-band spectra and iron line diagnostic

2000 ◽  
Vol 25 (3-4) ◽  
pp. 413-416 ◽  
Author(s):  
S. Del Sordo ◽  
D. Dal Fiume ◽  
M. Orlandini ◽  
S. Piraino ◽  
A. Santangelo ◽  
...  
Keyword(s):  
Broad Band ◽  
Iron Line ◽  
X Ray ◽  
Band Spectra

scholarly journals Spectroscopy Methods and Applications of the Tor Vergata Laser-Plasma Facility Driven by GW-Level Laser System

2011 ◽  
Vol 2011 ◽  
pp. 1-28 ◽  
Author(s):  
M. Francucci ◽  
P. Gaudio ◽  
S. Martellucci ◽  
M. Richetta
Keyword(s):  
Laser Plasma ◽  
Laser System ◽  
Line Emission ◽  
Pulsed Laser ◽  
Plasma Source ◽  
Laser Source ◽  
Solid Target ◽  
Glass Laser ◽  
X Ray ◽  
Level Laser

A review focused on plasma induced on solid target by GW-level pulsed laser source is presented. A description of the Tor Vergata laser-plasma source (TVLPS), at the Tor Vergata University in Rome, is given. Such a facility uses a 1  GW, tabletop, multistage Nd:YAG/Glass laser system, delivering infrared (IR) pulses with nanosecond width and 1064 nm wavelength (TEM00 mode). Its applications are discussed providing: wide analysis of IR → soft X-ray conversion efficiency (1.3–1.55 keV); measures and modeling of line emission in soft X-ray spectra, such as those from zinc plasma near Ne-like Zn XXI and from barium plasma near Ni-like Ba XXIX. Particular attention is devoted to high-n dielectronic Rydberg satellites for finding a useful diagnostic tool for plasma conditions. Dependence of plasma spectra on laser parameters is shown. Finally, microradiography applications are presented for thin biological samples. Images permit to visualize specific structures and detect bioaccumulation sites due to contamination from pollutants.

Development of shock-dynamics study with synchrotron-based time-resolved X-ray diffraction using an Nd:glass laser system

2020 ◽  
Vol 27 (2) ◽  
pp. 371-377 ◽  
Author(s):  
Sota Takagi ◽  
Kouhei Ichiyanagi ◽  
Atsushi Kyono ◽  
Shunsuke Nozawa ◽  
Nobuaki Kawai ◽  
...  
Keyword(s):  
Strain Rate ◽  
Shock Compression ◽  
Dynamic Compression ◽  
Laser System ◽  
Target Position ◽  
Experimental System ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Nd:Glass Laser

The combination of high-power laser and synchrotron X-ray pulses allows us to observe material responses under shock compression and release states at the crystal structure on a nanosecond time scale. A higher-power Nd:glass laser system for laser shock experiments was installed as a shock driving source at the NW14A beamline of PF-AR, KEK, Japan. It had a maximum pulse energy of 16 J, a pulse duration of 12 ns and a flat-top intensity profile on the target position. The shock-induced deformation dynamics of polycrystalline aluminium was investigated using synchrotron-based time-resolved X-ray diffraction (XRD) under laser-induced shock. The shock pressure reached up to about 17 GPa with a strain rate of at least 4.6 × 107 s–1 and remained there for nanoseconds. The plastic deformation caused by the shock-wave loading led to crystallite fragmentation. The preferred orientation of the polycrystalline aluminium remained essentially unchanged during the shock compression and release processes in this strain rate. The newly established time-resolved XRD experimental system can provide useful information for understanding the complex dynamic compression and release behaviors.

scholarly journals Recent highlights of the PALS research program

2005 ◽  
Vol 23 (2) ◽  
pp. 177-182 ◽  
Author(s):  
K. JUNGWIRTH
Keyword(s):  
Laser Ablation ◽  
Shock Waves ◽  
Broad Spectrum ◽  
Research Program ◽  
Laser Plasma ◽  
Laser System ◽  
Laser Beams ◽  
Treatment Results ◽  
X Ray ◽  
Power Densities

The Prague Asterix Laser System (PALS) research program covers a broad spectrum of laser–plasma experiments in the range of power densities of 1014-5 × 1016W/cm2, aimed at development and applications of laser plasma-based ion and soft X-ray sources of plasma based ultra-bright XUV lasers in particular. In parallel to these two main lines of research, various principal tasks of laser plasma physics are being studied, such as generation and propagation of laser-induced shock waves, laser ablation, and crater creation processes or laser imprint treatment. Results selected of numerous experimental projects performed at PALS within the period 2002–2004 are surveyed in the paper, experiments with intense soft XUV laser beams being highlighted on the first place.

scholarly journals Broad-band spectral study of X-ray transient MAXI J1820+070 using Swift/XRT and NuSTAR

2019 ◽  
Vol 487 (4) ◽  
pp. 5946-5951 ◽  
Author(s):  
Priya Bharali ◽  
Jaiverdhan Chauhan ◽  
Kalyanee Boruah
Keyword(s):  
Thermal Emission ◽  
Broad Band ◽  
Compact Object ◽  
Black Body ◽  
Gravitational Radius ◽  
X Ray ◽  
Stable Circular Orbit ◽  
Hard State ◽  
Best Fitting ◽  
Band Spectra

ABSTRACT We report on a NuSTAR and Swift/XRT observation of the newly discovered X-ray transient MAXI J1820+070. Swift/XRT and NuSTAR have concurrently observed the newly detected source on 2018 March 14. We have simultaneously fitted the broad-band spectra obtained from Swift/XRT and NuSTAR. The observed joint spectra in the energy range 0.6–78.0 keV are well modeled with a weak disc black-body emission, dominant thermal Comptonization, and relativistic reflection fraction. We have detected a fluorescent Iron-Kα line relativistically broadened and a Compton hump at ∼30 keV. We constrain the inner disc radius as well as the disc inclination angle, and their values are found to be 4.1$^{+0.8}_{-0.6}$RISCO (where RISCO ≡ radius of the innermost stable circular orbit) or 5.1$^{+1.0}_{-0.7}$ rg (where rg ≡ gravitational radius) and 29.8$^{+3.0}_{-2.7}$°, respectively. The best-fitting broad-band spectra suggest that the source was in the hard state and evolving. The source emission is best described by weak thermal emission along with strong thermal Comptonization from a relatively cold, optically thick, geometrically thin and ionized accretion disc. X-ray spectral modeling helps us to understand the accretion and ejection properties in the vicinity of the compact object.

scholarly journals X-ray and ion emission studies from subnanosecond laser-irradiated SiO2 aerogel foam targets

2017 ◽  
Vol 35 (3) ◽  
pp. 505-512 ◽  
Author(s):  
C. Kaur ◽  
S. Chaurasia ◽  
A.A. Pisal ◽  
A.K. Rossall ◽  
D.S. Munda ◽  
...  
Keyword(s):  
Laser Energy ◽  
Laser System ◽  
Line Emission ◽  
Plasma Temperature ◽  
X Rays ◽  
Plasma Parameters ◽  
X Ray ◽  
Spectral Ranges ◽  
Ion Emission

AbstractIn this experiment, a comparative study of ion and X-ray emission from both a SiO2 aerogel foam and a quartz target is performed. The experiment is performed using Nd:glass laser system operated at laser energy up to 15 J with a pulse duration of 500 ps with focusable intensity of 1013–1014 W/cm2 on target. X-ray fluxes in different spectral ranges (soft and hard) are measured by using X-ray diodes covered with Al filters of thickness 5 µm (0.9–1.56 keV) and 20 µm (3.4–16 keV). A 2.5 times enhancement in soft X-ray flux (0.9–1.56 keV) and a decrease of 1.8 times in hard X rays (3.4–16 keV) for 50 mg/cc SiO2 aerogel foam is observed compared with the solid quartz. A decrease in the flux of the K-shell line emission spectrum of soft X rays is noticed in the case of the foam targets. The high-resolution K-shell spectra (He-like) of Si ions in both the cases are analyzed for the determination of plasma parameters by comparing with FLYCHK simulations. The estimated plasma temperature and density are Tc = 180 eV, ne = 7 × 1020 cm−3 and Tc = 190 eV, ne = 4 × 1020 cm−3 for quartz and SiO2 aerogel foam, respectively. To measure the evolution of the plasma moving away from the targets, four identical ion collectors are placed at different angles (22.5, 30, 45, and 67.5°) from target normal. The angular distribution of the thermal ions are scaled as cosnθ with respect to target normal, where n = 3.8 and 4.8 for the foam and quartz, respectively. The experimental plasma volume measured from the ion collectors and shadowgraphy images are verified by a two-dimensional Eulerian radiative–hydrodynamic simulation (POLLUX code).

Materials For Laser-Plasma X-Ray Source Targets Applicable To Lithography

1993 ◽  
Vol 306 ◽  
Author(s):  
M. Chaker ◽  
J.F. Pelletier ◽  
J.C. Kieffer
Keyword(s):  
Conversion Efficiency ◽  
Laser Plasma ◽  
Experimental Studies ◽  
Plasma Temperature ◽  
Physical Aspect ◽  
Attractive Alternative ◽  
Temperature Plasma ◽  
Laser Target ◽  
X Ray ◽  
Projection Lithography

AbstractIn recent years, several X-ray lithography experiments involving laser plasma sources have been reported. The high X-ray conversion efficiency (η – 10%) in the keV range observed in various laboratories, using high laser intensities (I > 5 × 1012 W cm−2), has already made these sources an attractive alternative to the electron storage rings for X-ray lithography in proximity printing (XRL). In addition, X-rayproduction in the region around 130 Å has also been investigated at intensities of about 1011 W cm−2 for applications to X-ray Projection Lithography (XRPL). Conversion efficiency up to 1% into a 3 Å bandwidth has been demonstrated. In principle, a large variety of X-ray spectra can be obtained from a laser plasma source depending on the laser-target parameters. However, high conversion efficiencies, in a given spectral range, can only be achieved under specific plasma conditions (target atomic number, plasma temperature, plasma volume and spatio-temporal expansion...). This leads to some restrictions in possible target materials and irradiation conditions (laser wavelength, laser intensity, pulse duration). In this paper, we will discuss this physical aspect basing our analysis on both the theoretical and experimental studies of the X-ray spectra in different X-ray energy ranges and for various target atomic numbers. In addition, we will examine issues related to the laser plasma X-ray source design for both XRL and XRPL applications.

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