Ion energy measurements on MAST using a midplane RFEA

Ion energy measurements have been made in the scrape off layer of the Mega Amp Spherical Tokamak (MAST) using a midplane retarding field energy analyser (RFEA) in H-mode plasmas during the inter-edge localised mode (ELM) period and during type I and type III ELMs. During the inter-ELM period at distances of 3 to 8 cm from the last closed flux surface (LCFS), ion temperatures of 20 to 70 eV have been measured giving an ion to electron temperature ratio of 2 to 7 with a mean of 4. During type III ELMs, an ion temperature of 50 eV has been measured 3 to 6 cm from the LCFS which decreases to 30 eV at distances 11 to 16 cm from the LCFS. During type I ELMs, an ion temperature of 40 eV has been measured at a distance of 10 to 15 cm from the LCFS.Comment: 15 pages, 5 figure

Elusive Diagnosis of Superficial Peroneal Nerve Entrapment Case report

Isolated neuropathy of the superficial peroneal nerve (SPN) is a relatively rare type of peripheral neuropathy. It is linked to the mechanical entrapment of the SPN in predisposed locations of its anatomical pathway. Associated clinical findings are insufficient lifting of the latero-dorsal part of the foot, stepping on the lateral border of the foot, and commonly, a strong pain localized in the nerve dermatome.Case report. We describe a case of a 14-year-old female patient with right leg pain lasting 24 months. Repeated neurological examinations with negative findings on electromyography (EMG) were performed. The patient underwent a Steindler surgery for a suspected diagnosis of a heel spur, without any improvement. Despite complex pharmacotherapy, chronic pain developed. The patient was unable to walk, being bound to a wheelchair. Amputation of her lower limb under the knee was also considered. SPN entrapment was diagnosed at a physical examination at EuroPainClinics. Decompression of the SPN under local anaesthesia was performed at the clinic.Results. The symptoms improved immediately after the procedure, and following 2 months of rehabilitation, the patient was completely symptom-free. Her clinical state remains unchanged until this day.Conclusions. SPN entrapment is not a common diagnosis in the group of pain syndromes. Regarding the lower limb, it is imperative to include it on the list of differential diagnoses in cases of pain and functional disorders of the lateral muscle groups of the calf and leg. In the case of SPN entrapment, EMG findings may be negative

The next-generation ARC middleware

The Advanced Resource Connector (ARC) is a light-weight, non-intrusive, simple yet powerful Grid middleware capable of connecting highly heterogeneous computing and storage resources. ARC aims at providing general purpose, flexible, collaborative computing environments suitable for a range of uses, both in science and business. The server side offers the fundamental job execution management, information and data capabilities required for a Grid. Users are provided with an easy to install and use client which provides a basic toolbox for job- and data management. The KnowARC project developed the next-generation ARC middleware, implemented as Web Services with the aim of standard-compliant interoperability

ELM ion energies in the ASDEX Upgrade far scrape-off layer

1. Introduction. Type I ELMs carry a significant fraction of their energy W ELM across the scrape-off layer (SOL) and are the dominant source of the first wall thermal load and impurity sputtering. In ITER, W ELM will be considerably larger compared to present tokamaks and the ELM-wall interaction may be an issue for the first wall lifetime and impurity production. New measurements of the ELM ion energies by a retarding field analyzer (RFA) in the ASDEX Upgrade (AUG) far SOL are presented. Type I and, for the first time, mitigated ELMs are captured by a RFA at different W ELM and the outer midplane separatrix distance r sep . A fluid model of the ELM filament parallel transport [1] is employed to obtain the characteristic range of the ELM-averaged filament radial propagation speeds v r

Scrape Off Layer (SOL) transport and filamentary characteristics in high density tokamak regimes

A detailed cross-device investigation on the role of filamentary dynamics in high density regimes has been performed within the EUROfusion framework comparing ASDEX Upgrade (AUG) and TCV tokamaks. Both devices have run density ramp experiments at different levels of plasma current, keeping toroidal field or q95 constant in order to disentangle the role of parallel connection length and the current. During the scan at constant toroidal field, in both devices SOL profiles tend to develop a clear Scrape Off Layer (SOL) density shoulder at lower edge density whenever current is reduced. The different current behavior is substantially reconciled in terms of edge density normalized to Greenwald fraction. During the scan at constant q95 AUG exhibits a similar behaviour whereas in TCV no signature of upstream profile modification has been observed at lower level of currents. The latter behaviour has been ascribed to the lack of target density roll-over. The relation between upstream density profile modification and detachment condition has been investigated. For both devices the relation between blob-size and SOL density e-folding length is found independent of the plasma current, with a clear increase of blob-size with edge density normalized to Greenwald fraction observed. ASDEX Upgrade has also explored the filamentary behaviour in H-Mode. The experiments on AUG focused on the role of neutrals, performing discharges with and without the cryogenic pumps, highlighting how large neutral pressure not only in the divertor but at the midplane is needed in order to develop a H-Mode SOL profile shoulder in AUG

Modification of SOL profiles and fluctuations with line-average density and divertor flux expansion in TCV

A set of Ohmic density ramp experiments addressing the role of parallel connection length in modifying scrape off layer (SOL) properties has been performed on the TCV tokamak. The parallel connection length has been modified by varying the poloidal flux expansion f x . It will be shown that this modification does not influence neither the detachment density threshold, nor the development of a flat SOL density profile which instead depends strongly on the increase of the core line average density. The modification of the SOL upstream profile, with the appearance of what is generally called a density shoulder , has been related to the properties of filamentary blobs. Blob size increases with density, without any dependence on the parallel connection length both in the near and far SOL. The increase of the density decay length, corresponding to a profile flattening, has been related to the variation of the divertor normalized collisionality ##IMG## [http://ej.iop.org/images/0029-5515/57/11/116014/nfaa7db3ieqn001.gif] {$\Lambda_{\rm div}$} (Myra et al 2006 Phys. Plasmas 13 112502, Carralero et al , ASDEX Upgrade Team, JET Contributors and EUROfusion MST1 Team 2015 Phys. Rev. Let . 115 215002), showing that in TCV the increase of ##IMG## [http://ej.iop.org/images/0029-5515/57/11/116014/nfaa7db3ieqn002.gif] {$\Lambda_{\rm div}$} is not sufficient to guarantee the SOL upstream profile flattening