Solenoid

About: Solenoid is a research topic. Over the lifetime, 19278 publications have been published within this topic receiving 114721 citations.

RF coil system for an MR apparatus

Abstract: The invention relates to an RF coil system for an open MR apparatus The system includes a plurality of resonator elements which are arranged at the area of a patient ( 102 ) positioned in the examination volume of an MR apparatus The resonator elements are constructed at least partly as solenoid elements ( 104 ) whose conductor elements form open turns which are arranged around the patient ( 102 ) It is thus achieved that the RF field generated in the transmission mode and the sensitivity profile in the detection mode are limited as strictly as possible to the examination volume of interest At the same time RF field strengths that are adequate for medical imaging can be generated without exposing the patient to an unacceptable load

Measurement of the CMS Magnetic Field

Abstract: The measurement of the magnetic field in the tracking volume inside the superconducting coil of the Compact Muon Solenoid (CMS) detector under construction at CERN is done with a fieldmapper designed and produced at Fermilab. The fieldmapper uses 10 3-D B-sensors (Hall probes) developed at NIKHEF and calibrated at CERN to precision 0.05% for a nominal 4 T field. The precise fieldmapper measurements are done in 33840 points inside a cylinder of 1.724 m radius and 7 m long at central fields of 2, 3, 3.5, 3.8, and 4 T. Three components of the magnetic flux density at the CMS coil maximum excitation and the remanent fields on the steel-air interface after discharge of the coil are measured in check-points with 95 3-D B-sensors located near the magnetic flux return yoke elements. Voltages induced in 22 flux-loops made of 405-turn installed on selected segments of the yoke are sampled online during the entire fast discharge (190 s time-constant) of the CMS coil and integrated offline to provide a measurement of the initial magnetic flux density in steel at the maximum field to an accuracy of a few percent. The results of the measurements made at 4 T are reported and compared with a three-dimensional model of the CMS magnet system calculated with TOSCA.

Constructing a 4-Tesla Large Thin Solenoid at the Limit of what can BE Safely Operated

Abstract: The 4-tesla, 6 m free bore CMS solenoid has been successfully tested, operated and mapped at CERN during the autumn of 2006 in a surface hall and fully recommissioned in the underground experimental area in the autumn of 2008. The conceptual design started in 1990, the R&D studies in 1993, and the construction was approved in 1997. At the time the main parameters of this project were considered beyond what was thought possible as, in particular, the total stored magnetic energy reaches 2.6 GJ for a specific magnetic energy density exceeding 11 kJ/kg of cold mass. During this period, the international design and construction team had to make several important technical choices, particularly mechanical ones, to maximize the chances of reaching the nominal induction of 4 T. These design choices are explained and critically reviewed in the light of what is presently known to determine if better solutions would be possible today for constructing a new large high-field thin solenoid for a future detector magnet.

DEMO Central Solenoid Design Based on the Use of HTS Sections at Highest Magnetic Field

Abstract: Previous studies indicated that the use of high-temperature superconductors (HTS) in the highest field allows us achieving the required magnetic flux in the central solenoid (CS) of the European DEMO at a reduced outer diameter, which would enable a reduced overall size and cost of DEMO The proposed winding pack design of the CS1 module is based on ten layer-wound subcoils using an HTS, react and wind Nb3Sn, and NbTi conductors in the high, medium, and low field sections, respectively The design utilizes a stainless steel and a superconductor grading leading to different overall current densities in each of the ten subcoils Both, the hoop stress and the vertical loads are taken into consideration for determination of the required stainless steel cross-section in the winding pack The stainless steel grading has been found to have an even more pronounced effect on the overall subcoil current densities than the superconductor grading A preliminary estimation of the space required for the precompression structure is also reported

Compressed air preparation device for brake force adjusting system of commercial vehicle, has excited first solenoid controlled valve, with which pressure essentially remains in a line between compressor and stop valve

Abstract: The compressed air preparation device (10) has excited first solenoid controlled valve (14), with which the pressure essentially remains in a line between the compressor and the stop valve (18). The device has an air vent (3) and inlet connection (1) whereby inlet connection is provided for connection of a compressor. An independent claim is included for method for operation of compressed air preparation device.