Picosecond and femtosecond streak cameras: present and future designs

1980 ◽  
Vol 298 (1439) ◽  
pp. 281-285 ◽  
Keyword(s):  
Time Resolution ◽  
Time Domain ◽  
Optical Design ◽  
Preliminary Design ◽  
X Ray ◽  
Time Dispersion ◽  
Expected Performance ◽  
Experimental Values ◽  
Imaging Properties ◽  
Streak Tube

For many applications of time-domain spectroscopy it is desirable to improve the time resolution of electron-optical streak cameras to less than 200 fs in the u.v. visible and i.r. and to ca . 1 ps at X-ray wavelengths. A suite of interactive computer programs has been developed for electron-optical design, taking into account time dispersion. It is possible to analyse rapidly the details of both spatial and temporal imaging properties of currently available streak tubes and to optimize the designs for particular applications. The computed results are shown to be in excellent agreement with the experimental values for the Photochron II streak tube. The expected performance characteristics of a preliminary design for a new tube, the Photochron III, are given.

Discovery and Opportunity in the X-Ray Time Domain

2017 ◽  
Vol 14 (S339) ◽  
pp. 143-143
Author(s):  
D. Haggard
Keyword(s):  
Time Resolution ◽  
Time Domain ◽  
State Of The Art ◽  
Rapid Expansion ◽  
High Time ◽  
High Time Resolution ◽  
X Ray ◽  
Reverberation Mapping

AbstractAmbitious X-ray observatories have enabled a rapid expansion in our knowledge of the X-ray time domain. With state-of-the-art facilities like Chandra, XMM Newton, and Swift performing surveys for over a decade (and counting), variability catalogues are becoming increasingly rich. Meanwhile, high time-resolution from the likes of NuSTAR and NICER (and RXTE before them) continue to uncover the richness of individual systems. These efforts have revealed a likely pulsar-ULX connection and possible magnetar oscillations, and have enabled reverberation mapping of AGN – to name only a few results. The talk reviewed recent highlights from the X-ray time domain, and described briefly what we hope to achieve with up-coming and proposed X-ray missions including HEX-P, Athena, XARM, eROSITA, STROBE-X, eXTP and TAP.

Time-Domain Instrumentation at ESO

2017 ◽  
Vol 14 (S339) ◽  
pp. 172-175
Author(s):  
V. D. Ivanov
Keyword(s):  
Time Resolution ◽  
Time Domain ◽  
Response Mode ◽  
Rapid Response ◽  
X Ray ◽  
European Southern Observatory ◽  
Wide Range ◽  
Quasar Variability ◽  
X Ray Binaries

AbstractOver the years the European Southern Observatory (ESO) has offered a number of time-domain instruments that enable the user to achieve time resolution as small as milliseconds. They have been used for a wide range of applications, from binary studies with Lunar occultations, characterisation of X-ray binaries and exoplanet transits, to quasar variability. Furthermore, ESO provides a target-of-opportunity (ToO) rapid-response-mode (RRM) channel to trigger quick follow-up observations within as little delay as minutes after a transient has been detected. This talk reviewed the available time-domain observing modes and instruments at ESO, giving priority to FORS2, HAWKI and UltraCam. It described the ToO and RRM, and gave examples of the most common science cases that take advantage of those channels and capabilities.

scholarly journals Single-Photon Detection Module Based on Large-Area Silicon Photomultipliers for Time-Domain Diffuse Optics

Instruments ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 18
Author(s):  
Fabio Acerbi ◽  
Anurag Behera ◽  
Alberto Dalla Mora ◽  
Laura Di Sieno ◽  
Alberto Gola
Keyword(s):  
Time Resolution ◽  
Time Domain ◽  
Single Photon ◽  
Building Blocks ◽  
The Body ◽  
Single Photon Detection ◽  
Silicon Photomultipliers ◽  
Photon Detection ◽  
Instrument Response Function ◽  
Diffuse Optics

Silicon photomultipliers (SiPM) are pixelated single-photon detectors combining high sensitivity, good time resolution and high dynamic range. They are emerging in many fields, such as time-domain diffuse optics (TD-DO). This is a promising technique in neurology, oncology, and quality assessment of food, wood, and pharmaceuticals. SiPMs can have very large areas and can significantly increase the sensitivity of TD-DO in tissue investigation. However, such improvement is currently limited by the high detector noise and the worsening of SiPM single-photon time resolution due to the large parasitic capacitances. To overcome such limitation, in this paper, we present two single-photon detection modules, based on 6 × 6 mm2 and 10 × 10 mm2 SiPMs, housed in vacuum-sealed TO packages, cooled to −15 °C and −36 °C, respectively. They integrate front-end amplifiers and temperature controllers, being very useful instruments for TD-DO and other biological and physical applications. The signal extraction from the SiPM was improved. The noise is reduced by more than two orders of magnitude compared to the room temperature level. The full suitability of the proposed detectors for TD-DO measurements is outside the scope of this work, but preliminary tests were performed analyzing the shape and the stability of the Instrument Response Function. The proposed modules are thus fundamental building blocks to push the TD-DO towards deeper investigations inside the body.

CHOOCH: a program for deriving anomalous-scattering factors from X-ray fluorescence spectra

2001 ◽  
Vol 34 (1) ◽  
pp. 82-86 ◽  
Author(s):  
Gwyndaf Evans ◽  
Robert F. Pettifer
Keyword(s):  
Absorption Edge ◽  
Fluorescence Spectra ◽  
Heavy Atom ◽  
Fortran Program ◽  
Anomalous Scattering ◽  
Tabular Data ◽  
X Ray ◽  
Scattering Factor ◽  
Experimental Values ◽  
Kronig Relation

A Fortran programCHOOCH, which derives experimental values of the anomalous-scattering factorsf′′ andf′ from X-ray fluorescence spectra, is described. The program assumes knowledge of theoretical values for the imaginary term,f′′, of the anomalous-scattering factor away from the absorption edge to scale the experimental fluorescence spectrum and thus derive values off′′ near the absorption edge, where tabular data are inappropriate. The Kramers–Kronig relation is used to calculate the real part,f′, of the anomalous-scattering factor. The program aids the decision-making process in macromolecular crystallographic experiments where optimal wavelength selection is required. Magnitudes off′ andf′′ at selected wavelengths can later be used as starting values for heavy-atom refinement with crystallographic phasing programs.

scholarly journals Theoretical and experimental comparative studies of nonlinear optical properties for selected melaminium compounds

2010 ◽  
Vol 8 (6) ◽  
pp. 1192-1202 ◽  
Author(s):  
Marek Drozd ◽  
Mariusz Marchewka
Keyword(s):  
Optical Properties ◽  
Acetic Acid ◽  
Nonlinear Optical ◽  
Time Dependent ◽  
X Ray ◽  
Hartree Fock ◽  
Optical Applications ◽  
Experimental Values ◽  
Nonlinear Optical Applications ◽  
Theoretical Results

AbstractThe bis(melaminium) sulphate dihydrate, 2,4,6-triamine-1,3,5-triazin-1,3-ium tartrate monohydrate, 2,4,6-triamine-1,3,5-triazin-1-ium hydrogenphthalate, 2,4,6-triamine-1,3,5-triazin-1-ium acetate acetic acid solvate monohydrate, 2,4,6-triamine-1,3,5-triazin-1-ium bis(selenate) trihydrate, melaminium diperchlorate hydrate, melaminium bis(trichloroacetate) monohydrate and melaminium bis(4-hydroxybenzenesulphonate) dihydrate were discovered recently as perspective materials for nonlinear optical applications. On the basis of X-ray structures for eight melaminium compounds the time dependent Hartree Fock (TDHF) method was used for calculation of the polarizability, and first and second hyperpolarizability. Detailed directional studies of calculated hyperpolarizability for all investigated melaminium compounds are shown. The theoretical results are compared with experimental values of β.

X-ray powder diffraction analysis of a nonlinear optical material o–chlorobenzol–benzoyl thiourea

1997 ◽  
Vol 12 (1) ◽  
pp. 47-48 ◽  
Author(s):  
Zong-ming Jin ◽  
Bo Zhao ◽  
Weiqun Zhou ◽  
Zheng Jin
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Nonlinear Optical ◽  
Optical Material ◽  
Nonlinear Optical Material ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Figures Of Merit ◽  
Experimental Values

A nonlinear optical material, o–chlorobenzol–benzoyl thiourea (C14H11ClN2OS), has been characterized by X-ray powder diffraction. Experimental values of 2θ corrected for systematic errors, relative peak intensities, values of d, and the Miller indices of 78 observed reflection with 2θ up to 72° are reported. The powder diffraction data have been evaluated, and the figures-of-merit are reported. The unit cell parameters least-squares refined from 28 nonoverlapping peaks of the monoclinic compound with a P2 space group are a=13.2797(4) Å, b=12.4058(8) Å, c=8.1561(2) Å, β=95.398(1)°, V=1337.7(4) Å3, Z=4, Dx=1.444 g/cm3. © 1997 International Centre for Diffraction Data.

scholarly journals Chandra Studies of Supernova Remnants and Pulsars

2001 ◽  
Vol 205 ◽  
pp. 358-365
Author(s):  
Patrick Slane ◽  
John P. Hughes ◽  
Cara E. Rakowski ◽  
David N. Burrows ◽  
John A. Nousek ◽  
...  
Keyword(s):  
Time Resolution ◽  
Supernova Remnants ◽  
Angular Resolution ◽  
Fast Time ◽  
X Ray ◽  
Spatially Resolved ◽  
Unique Capability

With sub-arcsecond angular resolution accompanied by fast time resolution and spatially resolved spectral capabilities, the Chandra X-ray Observatory provides a unique capability for the study of supernova remnants (SNRs) and pulsars. Though in its relative infancy, Chandra has already returned stunning images of SNRs which reveal the distribution of ejecta synthesized in the stellar explosions, the distinct properties of the forward and reverse shocks, and the presence of faint shells surrounding compact remnants. Pulsar observations have uncovered jet features as well as small-scaled structures in synchrotron nebulae. In this brief review we discuss results from early Chandra studies of pulsars and SNRs.

Imaging properties of high aspect ratio absorption gratings for use in preclinical x-ray grating interferometry

2015 ◽  
Vol 61 (2) ◽  
pp. 527-541 ◽  
Author(s):  
Barbara Trimborn ◽  
Pascal Meyer ◽  
Danays Kunka ◽  
Marcus Zuber ◽  
Frederic Albrecht ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
X Ray ◽  
Imaging Properties

Optical design and simulation of Einstein Probe satellite follow-up x-ray telescope

2021 ◽  
Vol 60 (02) ◽  
Author(s):  
Yuxuan Zhu ◽  
Maoshun Li ◽  
Jingbin Lu ◽  
Yangji Yang ◽  
Min Cong ◽  
...  
Keyword(s):  
Optical Design ◽  
X Ray

scholarly journals Optical Short-Time Variations in GK Persei during the 1983 Outburst

1987 ◽  
Vol 93 ◽  
pp. 485-485
Author(s):  
H. Steinle ◽  
W. Pietsck
Keyword(s):  
Accretion Disk ◽  
Time Resolution ◽  
X Rays ◽  
X Ray ◽  
Time Variations ◽  
Short Time ◽  
First Time ◽  
Calar Alto

AbstractDuring the August 1983 outburst of the old nova GK Persei observations with EXOSAT showed for the first time a 351 second periodicity in X-rays.Our fast photometry (U(B)V with 25 sec time resolution) was made at the end of the outburst in the nights of September 29 , and October 1–3 , using the 2.2 meter telescope at Calar Alto (Spain).Optical variations up to 10% in U and 4% in V with periodicities in the range 350 to 360 seconds were found, lasting only for few cycles.A comparison with the extrapolated prediction of the X-ray maxima did not show a coincidence, but rather an anticoincidence in several cases. This supports a model of reprocessed X-rays at the inner edge of an accretion disk.

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