scholarly journals High-energy synchrotron X-ray tomography coupled with digital image correlation highlights likely failure points inside ITER toroidal field conductors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryan Warr ◽  
Matthew C. Jewell ◽  
Neil Mitchell ◽  
Alexander Rack ◽  
Jack Swanson ◽  
...  

AbstractTwo sections of heat-treated (HT) and non-heat-treated (NHT) Cable-in-Conduit Conductor (CICC) of a design similar to the ITER tokomak have been imaged using very high energy X-ray tomography at the ESRF beamline ID19. The sample images were collected at four temperatures down to 77 K. These results showed a greater degree of movement, bundle distortion and touching strands in the NHT sample. The HT sample showed non-linear movements with temperature especially close to 77 K; increasing non-circularity of the superconducting fibre bundles towards the periphery of the CICC, and touching bundles throughout the CICC. The images have highlighted where future design might improve potential weakness, in particular at the outer perimeters of the conductor and the individual sub-cable, ‘petal’ wraps.

1990 ◽  
Vol 16 (12) ◽  
pp. 1773-1803 ◽  
Author(s):  
P M Chadwick ◽  
T J L McComb ◽  
K E Turver

2019 ◽  
Vol 489 (4) ◽  
pp. 5076-5086 ◽  
Author(s):  
K K Singh ◽  
B Bisschoff ◽  
B van Soelen ◽  
A Tolamatti ◽  
J P Marais ◽  
...  

ABSTRACT In this work, we present a multiwavelength study of the blazar 1ES 1218+304 using near simultaneous observations over 10 yr during the period 2008 September 1 to 2018 August 31 (MJD 54710–58361). We have analysed data from Swift-UVOT, Swift-XRT, and Fermi-LAT to study the long term behaviour of 1ES 1218+304 in different energy bands over the last decade. We have also used the archival data from OVRO, MAXI, and Swift-BAT available during the above period. The near simultaneous data on 1ES 1218+304 suggest that the long term multiwavelength emission from the source is steady and does not show any significant change in the source activity. The optical/UV fluxes are found to be dominated by the host galaxy emission and can be modelled using the pegase code. However, the time averaged X-ray and γ-ray emissions from the source are reproduced using a single zone leptonic model with log-parabolic distribution for the radiating particles. The intrinsic very high energy γ-ray emission during a low activity state of the source is broadly consistent with the predictions of the leptonic model for blazars. We have investigated the physical properties of the jet and the mass of the supermassive black hole at the centre of the host galaxy using long term X-ray observations from the Swift-XRT which is in agreement with the value derived using blackbody approximation of the host galaxy. We also discuss the extreme nature of the source on the basis of X-ray and γ-ray observations.


Proceedings ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 9
Author(s):  
Ka-Wah Wong ◽  
Rodrigo S. Nemmen ◽  
Jimmy A. Irwin ◽  
Dacheng Lin

The nearby M87 hosts an exceptional relativistic jet. It has been regularly monitored in radio to TeV bands, but little has been done in hard X-rays ≳10 keV. For the first time, we have successfully detected hard X-rays up to 40 keV from its X-ray core with joint Chandra and NuSTAR observations, providing important insights to the X-ray origins: from the unresolved jet or the accretion flow. We found that the hard X-ray emission is significantly lower than that predicted by synchrotron self-Compton models introduced to explain very-high-energy γ -ray emission above a GeV. We discuss recent models to understand these high energy emission processes.


2010 ◽  
Vol 6 (S275) ◽  
pp. 215-223
Author(s):  
Valentí Bosch-Ramon

AbstractMicroquasars are X-ray binaries that show extended radio jets. These jets can accelerate particles up to relativistic energies that produce non-thermal emission from radio to TeV, and could also make a non-negligible contribution to the galactic CRs in some energy ranges. The orbital motion and compactness of these sources allow the study of high-energy astrophysical phenomena in extreme conditions that change in accessible timescales. In this work, I briefly discuss the production of broadband non-thermal emission in microquasars, putting special emphasis on the high- and the very high-energy bands.


2019 ◽  
Vol 626 ◽  
pp. A65
Author(s):  
A. Petriella

Aims. HESS J1844-030 is a newly confirmed TeV source in the direction of the X-ray pulsar wind nebula (PWN) candidate G29.4+0.1 and the complex radio source G29.37+0.1, which is likely formed by the superposition of a background radio galaxy and a Galactic supernova remnant (SNR). Many scenarios have been proposed to explain the origin of HESS J1844-030, based on several sources that are capable of producing very high energy radiation. We investigate the possible connection between the SNR, the PWN G29.4+0.1, and HESS J1844-030 to shed light on the astrophysical origin of the TeV emission. Methods. We performed an imaging and spectral study of the X-ray emission from the PWN G29.4+0.1 using archival observations obtained with the Chandra and XMM-Newton telescopes. Public radio continuum and HI data were used to derive distance constraints for the SNR that is linked to G29.37+0.1 and to investigate the interstellar medium where it is expanding. We applied a simple model of the evolution of a PWN inside an SNR to analyze the association between G29.4+0.1 and the radio emission from G29.37+0.1. We compared the spectral properties of the system with the population of TeV PWNe to investigate if HESS J1844-030 is the very high energy counterpart of the X-ray PWN G29.4+0.1. Results. Based on the morphology and spectral behavior in the X-ray band, we conclude that G29.4+0.1 is a PWN and that a point source embedded on it is the powering pulsar. The HI data revealed that the SNR linked to G29.37+0.1 is a Galactic source at 6.5 kpc and expanding in a nonuniform medium. From the analysis of the pulsar motion and the pressure balance at the boundary of X-ray emission, we conclude that G29.4+0.1 could be a PWN that is located inside its host remnant, forming a new composite SNR. Based on the magnetic field of the PWN obtained from the X-ray luminosity, we found that the population of electrons producing synchrotron radiation in the keV band can also produce IC photons in the TeV band. This suggests that HESS J1844-030 could be the very high energy counterpart of G29.4+0.1.


2014 ◽  
Vol 798 (1) ◽  
pp. 27 ◽  
Author(s):  
Naoki Isobe ◽  
Ryosuke Sato ◽  
Yoshihiro Ueda ◽  
Masaaki Hayashida ◽  
Megumi Shidatsu ◽  
...  
Keyword(s):  
X Ray ◽  
Γ Ray ◽  

2008 ◽  
Vol 17 (10) ◽  
pp. 1859-1866
Author(s):  
◽  
J. RICO

We report on the results from the observations in very high energy band (VHE, Eγ ≥ 100 GeV ) of the γ-ray binary LS I +61 303 and the black hole X-ray binary (BHXB) Cygnus X-1. LS I +61 303 was recently discovered at VHE by MAGIC1 and here we present the preliminary results from an extensive observation campaign, comprising 112 observation hours covering 4 orbital cycles, aiming at determining the time-dependent features of the VHE emission. Cygnus X-1 was observed for a total of 40 hours during 26 nights, spanning the period between June and November 2006. We report on the results of the searches for steady and variable γ-ray signals from Cygnus X-1, including the first experimental evidence for an intense flare, of duration between 1.5 and 24 hours.


2020 ◽  
Vol 904 (2) ◽  
pp. 91
Author(s):  
C. J. T. van der Merwe ◽  
Z. Wadiasingh ◽  
C. Venter ◽  
A. K. Harding ◽  
M. G. Baring
Keyword(s):  
X Ray ◽  

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