scholarly journals The use of muon radiography in safeguarding geological repositories

2021 ◽  
Vol 1 ◽  
pp. 279-280
Author(s):  
Lee Thompson ◽  
Katharina Aymanns ◽  
Irmgard Niemeyer ◽  
Christiane Vieh ◽  
Michael Weekes

Abstract. Muon radiography is a technique that harnesses naturally occurring cosmic radiation to noninvasively determine the density of an object of interest. The technique has many similarities to that of medical X-ray examinations and can supply detailed density maps of the object. We propose the application of muon radiography to aspects of the long-term monitoring of nuclear waste. In particular, muon radiography would provide valuable information on the overburden of a prospective underground geological repository and would be able to identify unknown features, such as undocumented underground passages. Similarly, muon tomography is capable of confirming that containers that have nominally been emptied are in fact empty. Such safeguard measures are important to maintain continuity of knowledge and to develop robust deterrent strategies against the removal of monitored nuclear material. The presentation focuses on the results of simulations that address some of these questions. Details of assumptions regarding the detector requirements and run times necessary to perform the imaging are discussed and results from the various removal and misuse scenarios are presented.

Author(s):  
G. L. CASE ◽  
E. ANZALONE ◽  
M.L. CHERRY ◽  
J. C. RODI ◽  
J. C. LING ◽  
...  

2000 ◽  
Vol 175 ◽  
pp. 719-722
Author(s):  
P. Reig ◽  
I. Negueruela ◽  
M.J. Coe ◽  
J. Fabregat ◽  
A.E. Tarasov

AbstractWe present results of our long-term monitoring of LS I +61° 235 in the optical and infrared bands. This Be/X-ray binary exhibits V/R variability in the Hα line, which can be explained in the framework of the Global One-armed Oscillation model: a high density perturbation moves around inside the circumstellar disc of the Be star. The V>R and V<R peaks occur when the perturbation moves towards and away from the observer, respectively. In this work we show that the perturbation also affects the He I λ6678Å and Paschen lines. We also report on a correlation between the infrared emission and the V/R variability.


2016 ◽  
Vol 12 (S324) ◽  
pp. 168-171 ◽  
Author(s):  
S. Komossa ◽  
D. Grupe ◽  
N. Schartel ◽  
L. Gallo ◽  
J. L. Gomez ◽  
...  

AbstractWe present results from our ongoing monitoring programs aimed at identifying and understanding Active Galactic Nuclei (AGN) in extreme flux and spectral states. Observations of AGN in extreme states can reveal the nature of the inner accretion flow, the physics of matter under strong gravity, and they provide insight on the properties of ionized absorbers and outflows launched near supermassive black holes (SMBHs). We present new results from our long-term monitoring of IC 3599, WPVS007, and Mrk 335, multi-wavelength follow-ups of the newly identified changing-look AGN HE 1136–2304, and UV–X-ray follow-ups of the binary SMBH candidate OJ 287 after its 2015 optical maximum, now in a new optical-X-ray–high-state.


2012 ◽  
Vol 11 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Zuzana Dakos ◽  
Daniel Kupka ◽  
Michal Kovařík ◽  
Katarína Jablonovská ◽  
Václav Krištúfek ◽  
...  

Abstract The genesis of acid mine drainage (AMD) is conditioned by existence of indigenous chemolithotrophic iron and sulfur oxidizing bacteria, especially of genus Acidithiobacillus. The result of the oxidizing weathering of metal sulfides is a sequential formation of ochreous precipitates in drainage systems and in the surroundings of AMD seepage on the surface. The long-term monitoring of AMD waters collected at the shaft Pech that receives the majority of waters draining the flooded Smolník mine area point out the enduring contamination risk of particular components in the environment of Smolník mine area. Elemental analysis, X-ray diffraction, Mossbauer spectroscopy and scanning electron microscopy of the ochreous precipitates formed from Smolník AMD stream revealed schwertmannite as the dominant solid phase in the precipitates. The chemical analysis of AMD effluents and the elemental composition of related sediments indicated considerable scavenging potential of the ochreous precipitates towards metal cations and oxyanions of arsenic and sulfate


2021 ◽  
Vol 1 ◽  
pp. 271-273
Author(s):  
Johann Arne Othmer ◽  
Karl-Heinz Lux ◽  
Ralf Wolters ◽  
Jörg Feierabend

Abstract. Within the framework of disposal of radioactive waste in Germany, the question arises how trust in the safety of a future deep geological repository and therefore the acceptability can be increased. One aspect that could contribute to this is the option of long-term monitoring of a deep geological repository by participation of the civil society. Whether and exactly how long-term monitoring of a deep geological repository leads to more trust, is being researched in the transdisciplinary work package TRUST within the research project TRANSENS in cooperation with members of the civil society. For the transdisciplinary processing of specific repository topics, a group of 16 persons from the civil society were recruited, none of which were stakeholders with respect to the topic of repositories. This group is designated as the Working Group Civil Society (AGBe). With the help of 12 members of the AGBe a first workshop on the topic “Monitoring and trust” was carried out on 13 March 2021, supported by partners of the LUH-IRS, the TUBS-IGG and the ETH-TdLab. This article is concerned with the preparation work, the course itself and the knowledge gained from the workshop. It deals with the preparation work in the form of a website and a report on information of the AGBe suitable for those who have been addressed, which has meant a challenge in view of the complexity of the topic of monitoring of a deep geological repository and prior knowledge of the AGBe. Furthermore, the course of the workshop, which was carried out online due to the coronavirus pandemic, is discussed, in which the 12 members of the AGBe and 10 scientists came together. The workshop began with a brainstorming on the topic of monitoring. This was followed by two specialist lectures, in which information on deep geological disposal and monitoring as well as the possibilities and limits of monitoring and monitoring conceptions was presented. The members of the AGBe were then divided into three groups, in which the central research questions of the workshop were discussed: Does a long-term near-field monitoring contribute to trust in the safety of deep geological disposal of radioactive waste? Which aspects of monitoring conceptions could increase trust in the implementation of near-field monitoring and which do not? After the presentation of the results from the group discussion a common discussion was first carried out in the plenum, in which a picture of the sentiments within the AGBe was finally formulated. Furthermore, the knowledge from the three discussion formats of the workshop is presented in this article. This includes the characterization of information and communication with the civil society as a central aspect in relationship with monitoring and trust. Furthermore, it showed that the AGBe views the long-term monitoring of a repository as a suitable measure for gaining trust. However, which aspects of monitoring conceptions contribute significantly to trust in the safe storage of radioactive waste is less clear after this first workshop and could not be conclusively answered. The results of this workshop with the AGBe reflect a first impression in the discussion on monitoring and trust. As monitoring is a complex topic with many interfaces on repository storage and sealing concepts, repository processes and multiple physical simulations as well as on societal topics, the discussion with the AGBe on the topic of monitoring should be continued during the course of the project. Thereby, it must be taken into consideration if the first positive assesments as well as the first AGBe specific requirements regarding long-term near-field monitoring activities will change with increasing knowledge.


2019 ◽  
Vol 492 (2) ◽  
pp. 2335-2346 ◽  
Author(s):  
Zhu Liu ◽  
He-Yang Liu ◽  
Huaqing Cheng ◽  
Erlin Qiao ◽  
Weimin Yuan

ABSTRACT We report the discovery of large amplitude X-ray variability in the low-luminosity active galactic nucleus NGC 7589, and present possible observational evidence for accretion mode transition in this source. Long-term X-ray flux variations by a factor of more than 50 are found using X-ray data obtained by Swift/X-Ray Telescope and XMM–Newton over 17 yr. Results of long-term monitoring data in the UV, optical, and infrared bands over ∼20 yr are also presented. The Eddington ratio λEdd increased from 10−3 to ∼0.13, suggesting a transition of the accretion flow from an advection dominated accretion flow to a standard thin accretion disc. Further evidence supporting the thin disc in the high-luminosity state is found by the detection of a significant soft X-ray component in the X-ray spectrum. The temperature of this component ($\sim 19^{+15}_{-7}$ eV, fitted with a blackbody model) is in agreement with the predicted temperature of the inner region for a thin disc around a black hole (BH) with mass of ∼107M⊙. These results may indicate that NGC 7589 had experienced accretion mode transition over a time-scale of a few years, suggesting the idea that similar accretion processes are at work for massive BH and BH X-ray binaries.


2020 ◽  
Vol 494 (2) ◽  
pp. 2178-2182
Author(s):  
Juhani Mönkkönen ◽  
Victor Doroshenko ◽  
Sergey S Tsygankov ◽  
Armin Nabizadeh ◽  
Pavel Abolmasov ◽  
...  

ABSTRACT We report on the analysis of the spin evolution of a slow X-ray pulsar GX 301–2 along the orbit using long-term monitoring by Fermi/Gamma-ray Burst Monitor. Based on the observationally confirmed accretion scenario and an analytical model for the accretion of angular momentum, we demonstrate that in this system, the neutron star spins retrogradely, that is, in a direction opposite to the orbital motion. This first-of-a-kind discovery of such a system proves the principal possibility of retrograde rotation in accreting systems with suitable accretion torque, and might have profound consequences for our understanding of the spin evolution of X-ray pulsars, estimates of their initial spin periods, and the ultimate result of their evolution.


1937 ◽  
Vol 33 (7) ◽  
pp. 940-940
Author(s):  
B. Ivanov

Based on his own observations a. believes that the treatment of congenital clubfoot should begin immediately after childbirth and consist of elastic manual redressing and independent active exercises of certain muscle groups. With strong resistance from the soft parts, the production of tenotomy and especially excision of the plantar aponeurosis is indicated. Violent and violent redress should be avoided; with old clubfoot and clubfoot in adults, when all attempts at plastic redressing are unsuccessful, surgery is indicated on the skeleton of the foot in the form of a wedge-shaped osteotomy, connected, if necessary, with intervention on the soft parts. Long-term monitoring is necessary throughout the entire growth period, even in successfully treated children; At the same time, X-ray observation of the centers of ossification is of great importance as an indicator of the result of treatment, since insufficient ossification, along with other moments, sooner or later can lead to relapses requiring long-term and vigorous treatment.


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