MCBXF magnets are orbit nested correctors for the HL-LHC project, an upgrade of the Large Hadron Collider (LHC). The magnet design consists of two nested dipoles, with an aperture of 150 mm. The ...magnets have been designed in two physical lengths, namely of 2.5 m (MCBXFA) and 1.5 m (MCBXFB), with the same cross section according to the necessities. Two prototypes and the first series magnet of the short version were manufactured at CIEMAT and assembled at CERN. The series production of the rest of the series magnets, 6 long (MCBXFA) and 11 short (MCBXFB) magnets, is being carried out at the premises of the company Elytt Energy. In this paper the powering test results of the first batch of MCBXFB magnets produced in the industry are presented, including both the results of training and magnetic measurements. An endurance test was made to check the reliability of the magnets after a large number of powering cycles and torque inversions.
MCBXFA magnets are long orbit nested correctors for the high luminosity upgrade of the LHC. They are the 2.5 m long version of the short orbit correctors MCBXFB, sharing the same cross-section. The ...components of the first prototype MCBXFAP1 have been produced by CIEMAT. The magnet was assembled in collaboration with CERN at its facilities (927 laboratory). This article depicts in first place the assembly steps of MCBXFAP1, which required the fabrication of custom tooling and faced some difficulties, mainly caused by the additional length compared to the short corrector. Shimming plan and magnet length adjustment are reported. After that, the powering test results at the CERN test station (SM-18) and the magnetic measurements campaign are presented.
2.5-m-long nested orbit correctors (so-called MCBXFA) are necessary for the upgrade of LHC, in the framework of HL-LHC project. These magnets provide 2.1 T in vertical and horizontal direction and ...they share the same cross-section of their shorter version MCBXFB, for which two prototypes and the first two series magnets have been manufactured and tested. In this paper we first present the specific aspects of MCBXFA magnet design: (i) field quality in the different powering scenarios, and (ii) mechanical analysis, with special attention to torque under combined operation. We then overview the manufacturing techniques, which are very similar to those used for MCBXFB, pointing out some difficulties that have arisen during the coil vacuum impregnation. The components of the prototype magnet are being produced by CIEMAT and the magnet will be assembled at CERN facilities.
MCBXF magnets are nested orbit combined correctors for the upgrade of the LHC. Two prototypes and the first series magnet were manufactured at CIEMAT and assembled at CERN, in the framework of the ...HL-LHC project. A fine tuning of the inner dipole design was introduced in the first series magnet to improve the mechanical support at the inner dipole coil ends, with a significant performance improvement. The contract to supply the rest of the series magnets, 6 long (MCBXFA) and 11 short (MCBXFB) magnets, has been awarded to the company Elytt Energy. This paper depicts the manufacturing and powering test results of the first MCBXFB magnet produced in Elytt Energy. In order to mitigate risks prior to the assembly of this magnet, a new reassembly of the second prototype magnet with shorter inner coils, according to the above-mentioned fine tuning, has been tested. The results of this powering test are also detailed.
The role of the Power Take-Off (PTO) as part of modern Wave Energy Converters is becoming more and more relevant and many efforts have been done or are ongoing to improve its performance especially ...in terms of force density and efficiency. Electric Linear PTOs are inherently the most efficient category, since they are really direct drives with no intermediate stages of energy conversion. Nevertheless, conventional electric machines are usually limited in force while their efficiency is better than other type of drives but still does not allow an intense energy capture in a broad band of wave periods. In this regard, superconductivity may become a very helpful alternative that allows improving both: efficiency and force density in spite of the technological difficulties that are introduced in the Wave Energy Converter. This paper, after justifying the need for better PTO performances, presents a new concept of superconducting PTO in which both, the stator and the translator work at cold temperature, performing a reciprocating displacement inside a flexible cryostat. The concept is later applied to a Cylindrical Switched Reluctance machine whose global design is also presented in the paper. This activity has been performed as one of the work packages of the EU H2020 Sea Titan Project in which also a resistive PTO with a novel configuration has been developed.
Fabrication and Power Test of Last MCBXFB Magnets Jardim, Carla Martins; Alcazar, C.; Dominguez, M. A. ...
IEEE transactions on applied superconductivity,
09/2022, Letnik:
32, Številka:
6
Journal Article
Recenzirano
MCBXFB magnets are nested orbit combined correctors for the upgrade of the LHC. The first three magnets were manufactured at CIEMAT and assembled at CERN, in the framework of the HL-LHC project. The ...power tests performed on the first prototype showed that the behavior when the dipoles were individually powered was excellent, but the training to reach nominal currents in combined operation was very long. Memory was lost when the torque direction changed. A similar behavior was found in the first power test of the second prototype described elsewhere. The origin of the problem has been identified as insufficient mechanical support at the inner dipole coil ends. This paper depicts the results of the power test after the reassembly of the second magnet with increased prestress on the coils. Shimming plan is discussed. Furthermore, a fine tuning of the inner dipole design has been introduced in the third magnet. The results of the power tests on that magnet show a significant performance improvement.
Nested combined orbit correctors are needed for the upgrade of LHC. They are developed at CIEMAT, in collaboration with CERN in the framework of HL-LHC project. There are two types of magnets, ...so-called MCBXFA and MCBXFB, with different lengths (2.5 and 1.5 m, respectively), but sharing the same cross section. The coils of both magnets are wound with the same Rutherford-type NbTi cable, composed of 18 strands of 0.48 mm diameter, insulated with a braided glass fiber sleeve. Various magnet protection schemes were considered for MCBXF magnets. In this work, self-protection, energy extraction resistor and quench heaters are discussed emphasizing advantages and disadvantages of each strategy. This analysis is supported by quench calculations performed with Squid (CIEMAT in-house developed code) and Roxie. Selected quench simulation results are presented and compared with measurements done on magnet prototypes. Based on the presented study, a protection scheme with energy extraction resistor was selected for the series magnets. The value of the resistor was optimized and related quench calculations are also included.
The ubiquitin–proteasome system (UPS) plays a fundamental role in protein degradation in neurons, and there is strong evidence that it fulfills a key role in synaptic transmission. The aim of the ...present work was to study the implication of one component of the UPS, the HERC1 E3 Ubiquitin Ligase, in motor function and neuromuscular transmission. The tambaleante (tbl) mutant mouse carries a spontaneous mutation in HERC1 E3 Ubiquitin Ligase, provoking an ataxic phenotype that develops in the second month of life. Our results show that motor performance in mutant mice is altered at postnatal day 30, before the cerebellar neurodegeneration takes place. This defect is associated with by: (a) a reduction of the motor end-plate area, (b) less efficient neuromuscular activity in vivo, and (c) an impaired evoked neurotransmitter release. Together, these data suggest that the HERC1 E3 Ubiquitin Ligase is fundamental for normal muscle function and that it is essential for neurotransmitter release at the mouse neuromuscular junction.
Aliens will provide Vergara-Tabares, David L.; Toledo, Martín; García, Emiliano ...
Oecologia,
09/2018, Letnik:
188, Številka:
1
Journal Article
Recenzirano
Frugivorous birds are able to track spatiotemporal changes in fruit availability. Food resource fluctuations, characteristic of seasonal environments, can be affected by the naturalization of exotic ...ornithocorous plants. In the mountain forest of central Argentina, invasive shrubs of the genus Pyracantha provide a new temporal resource that modifies fluctuations of natural resource availability because the invasives fructify in autumn–winter (largely uncoupled with the fruiting of native species). The contrasting patterns of resource fluctuation between non-invaded and invaded areas throughout the year provide a good study system to test predictions of the fruit-tracking hypothesis, and to understand the relationship between food resources offered by fleshy fruited invasives and abundances of avian trophic guilds. By means of point counts conducted during five time periods at invaded and non-invaded sites we found that the presence of Pyracantha, and time periods, significantly affected frugivorous bird abundance, which in autumn–winter was greater in invaded sites and in spring–summer similar between invaded and non-invaded sites. On the other hand, granivores and insectivores did not show a significant relationship with the presence of Pyracantha. Abundances of the most common seed disperser were significantly affected by the interaction between time period and presence of Pyracantha. These results indicate that the abundances of birds that legitimately disperse Pyracantha seeds are temporally and spatially associated with fruit abundance provided by this exotic plant. This underscores fruit availability as an important ecological factor affecting frugivorous bird abundance, and suggests that Pyracantha seed dispersers are capable of detecting changes in the availability of its fruit, likely contributing to the effectiveness of its dispersal.
A new linear accelerator, i.e., the European X-ray Free-Electron Laser (XFEL), is under construction at DESY in Hamburg. The construction started in early 2009, and the commissioning is planned for ...2016. The design energy of the electron beam is 17.5 GeV (0.05-4.7 nm wavelength), and more than 27000 flashes/s are expected. The accelerator contains 102 cryomodules equipped with a string of eight superconducting RF cavities and one superconducting magnet package. Each magnet consists of two cos -θ-type correction dipoles, horizontal and vertical deflecting. They are glued onto the surface of the beam pipe and are surrounded by a superferric quadrupole magnet. The package is mounted inside of a compact stainless steel vessel with a length of 30 cm and a diameter of 20 cm. Each package and current lead assembly was tested separately at room temperature and together at 2 K in a dedicated superfluid helium cryostat at DESY. A summary of the results is reported here. During the cold test, special emphasis was given to hysteresis and persistent current effects, as the operating current varies from very low currents at the beginning of the accelerator to the full design current 50 A at the end.
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