In the context of EP R&D, CERN is working on conceptual designs for a possible multi-purpose superconducting magnet test beam facility to be used for future detector and electronic device testing. ...The facility may serve as a replacement of the existing M1 or Morpurgo H8 magnets. The new facility is envisioned to serve all the testing requirements for the next generation of high energy physics particle detectors. Two separate concepts are proposed to satisfy the replacement needs. The magnet will take either the form of a split solenoid, allowing dual use as a dipole or solenoid, or a skateboard tilted racetrack design, allowing dipole function. Both designs allow for at least <inline-formula><tex-math notation="LaTeX">1 \,{\mathrm{m}^{\mathrm{3}}}</tex-math></inline-formula> testing volume and a magnetic field up to 4-T. It is envisioned to use Niobium Titanium Rutherford cables with a Nickel-Aluminium stabiliser. The operation temperature will be 4.5 K with two-phase helium cooling. The stray fields are minimised to stay below 12 mT at a distance of 5 m from the central point.
Arc suppression Snubbers offer safety in high energy superconducting magnet systems. Large superconducting magnets may have arcing across their breakers at the moment of slow dump initiation ...resulting from a sudden current redistribution in the powering circuit. The ATLAS Experiment at CERN experiences such arcing with its 7.3 H Toroidal magnet powering circuit. To discharge the magnets, the current is redistributed to a parallel branch called the Run Down Unit (RDU) by means of a breaker. Due to the physical layout and other metallic components in the vicinity, the power supply and RDU branches have undesirable and unavoidable parasitic inductance, causing a voltage spike over the main breakers at the moment of opening. The resulting arcing deteriorates the breaker contacts, resulting in increased operating temperatures and a more frequent need for maintenance. The arc suppression system developed takes the form of an RC Snubber (Resistor-Capacitor). The Snubber offers the current a low-impedance path, thus smoothing out the current redistribution and suppressing the voltage spike. This initial charging period of the capacitors gives the current enough time to overcome the parasitic inductance, therefore allowing the RDU to smoothly ramp up without a sudden voltage spike. To test the concept, a 1/50th scale demonstrator was developed and showed successful results. After the demonstrator, endurance testing of the electrolytic capacitors was performed to ensure no degradation of the charging characteristics for an equivalent of 20 years of operation. The Snubber was manufactured and implemented with successful results on the ATLAS Toroidal powering circuit.
Abstract
In the framework of the High Luminosity Upgrade of the LHC (HL-LHC) the beam intensity from the injectors must be doubled while keeping longitudinal beam parameters unchanged. As such, ...high-quality beams with high intensities are required also from the Proton Synchrotron (PS). The beam coupling impedance plays a crucial role and mitigation measures must be taken to remain within a stringent impedance budget. Kicker magnets are important contributors to the overall broadband impedance of the PS. Moreover, the detailed study of kicker impedances revealed additional resonant modes which may be critical for the beam stability. The longitudinal beam coupling impedance for the fast extraction kicker KFA79 is presented in this study, and a solution to reduce the impedance of the critical resonant modes is introduced. Electromagnetic (EM) simulations have been performed to determine the impedance behaviour. Finally, the insertion of transition pieces between magnet modules is presented as a measure for mitigating the low frequency resonant impedance contributions.
Despite the growing interest in the ability of foreseeing (episodic future thinking), it is still unclear how healthy people construct possible future scenarios. We suggest that different future ...thoughts require different processes of scene construction. Thirty-five participants were asked to imagine desirable and less desirable future events. Imagining desirable events increased the ease of scene construction, the frequency of life scripts, the number of internal details, and the clarity of sensorial and spatial temporal information. The initial description of general personal knowledge lasted longer in undesirable than in desirable anticipations. Finally, participants were more prone to explicitly indicate autobiographical memory as the main source of their simulations of undesirable episodes, whereas they equally related the simulations of desirable events to autobiographical events or semantic knowledge. These findings show that desirable and undesirable scenarios call for different mechanisms of scene construction. The present study emphasizes that future thinking cannot be considered as a monolithic entity.
Chronic subdural haematoma is one of the most common entities encountered in daily practice. Many methods of treatment have been reported, each with its own advantages and disadvantages.
The authors ...present a novel technique for the management of chronic subdural haematoma which is a variation of a closed drainage system. After evacuation of the haematoma through a single burr hole, we inserted a Jackson Pratt drain into the subgaleal space, with suction facing the burr hole, allowing for continuous drainage of the remaining haematoma.
We used the method for over 4 years to treat 224 patients. Seventeen patients (7.6%) needed a second operation for a recurrence of the haematoma no patient required a third operation. Postoperative complications developed in 3 patients. Two patients died while in the hospital, a mortality rate of 0.9%.
The use of suction assisted evacuation, is followed by results that compare satisfactorily to reports of previous methods, with a low rate of recurrence and complications. It is relatively less invasive and can be used in high risk patients.
We describe a rare case of metastatic intra-suprasellar adenocarcinoma from colonic cancer mimicking a meningioma of the "diaphragma sellae". Autopsy studies indicate breast and lung carcinoma to be ...the most frequent primary tumor metastasizing this site, particularly in patients with systemic spread. While diabetes insipidus is reported to be one of the commonest symptoms in these cases, the only clinical manifestation of the tumor in our patient was a bitemporal hemianopia, while the primary tumor remained asymptomatic. In the available literature are reported only two pituitary metastasis from operated colon carcinoma. In both cases the diagnosis of the colon cancer preceded the pituitary operation. The clinico-pathological and neuroradiological aspects of this unusual lesion are analyzed in the light of the relevant literature on the topic focusing on recent MRI acquisitions.
This paper describes the software developed by the authors in order to introduce the flexibility and computing power of a modern personal computer in an existing visual electrophysiology laboratory. ...The basic problems that a programmer must solve in order to implement the main tasks requested are discussed. Such problems include signal acquisition, signal averaging, artifact rejection, time domain analysis, frequency domain analysis and data management. The software developed following our guidelines makes it possible for a personal computer equipped with a commercial analog-to-digital converter to interface directly with the physiologic amplifiers and visual stimulators commonly used either for classical electroretinography or for pattern and focal electroretinography.
Summary form only given. An automatic management system set up in order to assess and optimize the reduction of hospital instrumentation maintenance costs is discussed. The system is coded in the ...ORACLE language and it works in a PC environment.< >
