Prototype detector for 6-keV x-rays using nine series arrays of tunnel junctions

1994 ◽  
Author(s):  
William C. Barber ◽  
Roger W. Bland ◽  
Robert T. Johnson ◽  
Kenneth E. Laws ◽  
Julie S. Lee ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
X Rays ◽  
Prototype Detector

Effects of Quasiparticle Diffusion in Nb-Based Superconducting Tunnel Junctions Under X-Rays Irradiation

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1247-1252
Author(s):  
Emanuela Esposito ◽  
Luigi Frunzio ◽  
Loredana Parlato ◽  
Roberto Cristiano ◽  
Mikhall Lisitskii ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Signal Amplitude ◽  
Radiation Detectors ◽  
Superconducting Tunnel Junctions ◽  
X Rays ◽  
Theoretical Limit ◽  
X Ray ◽  
Operational Temperature ◽  
Amplitude Spectra ◽  
Quasiparticle Diffusion

A novel class of sensors is constituted by radiation detectors based on superconducting tunnel junctions, which could lead in the next future to an advanced instrumentation with an interesting fall out for applications. So far, this area is restricted to LTc superconductors. Among them, niobium has the highest critical temperature and is therefore less demanding in terms of operational temperature. The best performances achieved so far in pure Nb-based junction are far away from the expected theoretical limit. The reason of this discrepancy could be attributed to various problems. Quasiparticle diffusion and edge losses seem to be responsible for the broadening of the signal amplitude spectra so often observed and reported in literature. In this paper we report on efforts to investigate the response to X-Ray of Nb-based superconducting tunnel junctions in terms of a model which includes the quasiparticle diffusion and the edge losses. Our model takes into account the contribution from both the electrodes of the junction and well reproduces the experimental data.

Output signal from Nb-based tunnel junctions by irradiation of 6 keV X-rays

1991 ◽  
Vol 27 (2) ◽  
pp. 2661-2664 ◽  
Author(s):  
K. Ishibashi ◽  
K. Mori ◽  
K. Takeno ◽  
T. Nagae ◽  
Y. Matsumoto ◽  
...  
Keyword(s):  
Output Signal ◽  
Tunnel Junctions ◽  
X Rays

Spectral features of substrate phonon events obtained by illuminating superconducting tunnel junctions with X-rays

2001 ◽  
Vol 11 (1) ◽  
pp. 708-711
Author(s):  
C. Otani ◽  
T. Ikeda ◽  
H. Kato ◽  
K. Kawai ◽  
H. Miyasaka ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Superconducting Tunnel Junctions ◽  
Spectral Features ◽  
X Rays

Detection of 6 keV X-rays by Using Large-Size Nb-Based Tunnel Junctions

1990 ◽  
pp. 1029-1032
Author(s):  
K. Ishibashi ◽  
K. Takeno ◽  
K. Mori ◽  
T. Sakae ◽  
Y. Matsumoto ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
X Rays ◽  
Large Size

Application of crystal absorbers coupled to superconducting tunnel junctions for the measurement of x rays

1995 ◽  
Author(s):  
Christian Erd ◽  
Abel Poelaert ◽  
Peter Verhoeve ◽  
Nicola Rando ◽  
Anthony J. Peacock
Keyword(s):  
Tunnel Junctions ◽  
Superconducting Tunnel Junctions ◽  
X Rays

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

The Clinical, Roentgenological and Morphological Effects of an Acute Exposure of Phosgene on the Lungs of Dogs

1971 ◽  
Vol 29 ◽  
pp. 236-237
Author(s):  
R. F. Bils ◽  
W. F. Diller ◽  
F. Huth
Keyword(s):  
Latent Period ◽  
Chemical Industry ◽  
Toxic Substance ◽  
Lung Edema ◽  
X Rays ◽  
Beagle Dogs ◽  
Male And Female ◽  
Morphological Alterations ◽  
Before And After ◽  
Electron Microscopes

Phosgene still plays an important role as a toxic substance in the chemical industry. Thiess (1968) recently reported observations on numerous cases of phosgene poisoning. A serious difficulty in the clinical handling of phosgene poisoning cases is a relatively long latent period, up to 12 hours, with no obvious signs of severity. At about 12 hours heavy lung edema appears suddenly, however changes can be seen in routine X-rays taken after only a few hours' exposure (Diller et al., 1969). This study was undertaken to correlate these early changes seen by the roengenologist with morphological alterations in the lungs seen in the'light and electron microscopes.Forty-two adult male and female Beagle dogs were selected for these exposure experiments. Treated animals were exposed to 94.5-107-5 ppm phosgene for 10 min. in a 15 m3 chamber. Roentgenograms were made of the thorax of each animal before and after exposure, up to 24 hrs.

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