For the alignment of the magnetic axes of PETRA III quadrupoles the tolerances are very tight. The accuracy requirements by the machine optics for the magnets in one girder cell are below 50 mum, ...both laterally and vertically. This leads to a girder concept commonly used in several synchrotron facilities around the world. A new alignment concept using multiple laser trackers is shown in detail and the principle of adjustment is explained. A new concept of rigidly connecting the magnets to the massive girder structure is shown, which is very effective in terms of stability and nevertheless cost efficient. Experiments show the feasibility of these ideas and prove an alignment accuracy below 40 mum. The results of dynamic analysis of this new girder system are shown.
Magnets for the PETRA-III Project Bondarchuk, E.; Doinikov, N.; Ivkin, V. ...
IEEE transactions on applied superconductivity,
06/2006, Letnik:
16, Številka:
2
Journal Article
Recenzirano
The work has been carried out at the Efremov Institute according to the new PETRA-III machine optics. Normal-conducting magnets (quadrupole, dipole and corrector magnets) for the PETRA-III project ...were designed and calculated. Prototypes were built and magnetic measurements were carried out. Two precision quadrupole magnets with asymmetrical yoke lengths were developed. Their apertures are 70 mm and their design gradients 21.5 T/m. The integral field nonlinearity in the good field region (GFR), r o < 25 mm should be less than 0.0005. The new dipole magnets for the PETRA-III project have a H-shaped magnetic yoke with a length of 1 m. In the GFR area of 60 mm times 36 mm a magnetic field of B max = 1 T should be obtained. Within the GFR limits the integral field nonlinearity should be less than 0.0005, which is achieved by profiling the poles (longitudinal chamfers, slants and shims). The vertical correction dipole magnet has a horizontal magnetic field of B X = 0.062 T, its aperture is 112 mm times 50 mm and its total length, including the coil end parts, is limited to L = 200 mm. The authors have designed two versions one with air-cooling and one with water-cooling. Results of the magnetic measurements are given and compared with the simulation
Within the framework of the HERA luminosity upgrade project Scanditronix Magnet AB has designed in collaboration with AMACC AB, IBA S.A. and DESY a septum-like dipole for the compensation of orbit ...differences between e/sup +/-p and e~-p collisions at HERA. The magnet yoke is 640 mm long, 415 mm wide and 550 mm high. The total magnet length is 930 mm. The pole distance is 70 mm, the "good field" region is /spl plusmn/ 20 mm centered around the nominal proton orbit. To meet the high field quality requirements for the whole range of field excitation between 0.1 T and 1.1 T VACOFLUX shims have been added to the pole edges to reduce saturation effects. The air gap is extended from the pole region by 235 mm to allow incoming synchrotron radiation light to pass through the magnet without being scattered. The separation between proton and electron beam at the magnet position at 18.88 m away from the interaction point is 121 mm. Carefully chosen thickness of the return yoke, a 13 mm thick shielding plate between proton and electron beam and 40 mm thick mirror plates on the front faces of the magnet reduce the field outside the magnet well below the tolerable value of 0,5/sub */10/sup -3/ T/sub */m integrated along the e-orbit.
The results of calculations and the. key design problems for the normal-conducting septum magnet for the Main Extraction Line of the TESLA linear collider are presented. The septum magnet is required ...to vertically deflect the so-called "spent beam" (after the interaction point) into the extraction line channel, while leaving the incoming (oppositely charged) beam undisturbed. The distance between the incoming beam and the copper septum is about 9 mm. The total length of the magnet core is 16 m. The 0.175 T magnetic field in 85 mm gap is produced by the copper winding and steel core. The septum is 5 mm thick. The stray field should not exceed 1 G. The septum-magnet should operate in the continuous regime. The required distribution of the magnetic field and the pole dimension of the septum-magnets have been calculated and optimized using two-dimensional models. A full-scale mock-up of one section of the septum-magnet has been developed and will be constructed for testing at the D.V. Efremov Scientific Research Institute of Electrophysical Apparatus.
The Efremov Institute and DESY have designed in collaboration high performance normal conducting quadrupole magnets for the HERA luminosity upgrade. One of the most ambitious is the type GA. It has a ...length of 3.85 m, a pole radius of 35 mm and must provide a maximum gradient of 26 T/m. The required field nonlinearity is /spl Delta/B/B/spl les/3/spl times/10/sup -4/ at a reference radius of 25 mm. A special feature is a clearance between the coil and the iron yoke that holds the separate electron beam pipe. This contribution deals with the production of the magnets and the results of the mechanical as well as magnetic measurements in comparison with the design values.
The Efremov Institute and DESY have designed in collaboration high performance normal conducting septum half-quadrupole magnets for the HERA luminosity upgrade. These magnets of the type GM have a ...length of 3.4 m. The 85 mm thick vertical mirror plate is cut out near the origin to provide a septum of 5 mm thickness. By this way a virtually field free space allows the passage of the separate e-beam very close to the high gradient field region.
The magnet yokes for most of the Hadron Electron Ring Accelerator magnets are made from 5-mm thick fine-blanked laminations. Differences in the measured and calculated field distributions using the ...specified values for the relative permeability are explained by distortions of the magnet steel caused by cold deformation in the cutting edge zones during the fine blanking. A comparison of fine-blanked, laser-cut and lathe-turned annular samples made from the same starting material shows that a reduction of the relative permeability and an increase of the coercive force depend strongly on the volume of the areas distorted in the fabrication process. Better agreement between calculated and measured field distribution was achieved by using properly chosen permeability curves taking into account the cold deformation from the lamination production. The influence of the production process on the magnetic properties of laminations can be reduced and even completely mitigated by additional heat treatment.< >
Field measurements of the compensating solenoids in the HERA e-p storage-ring Beckhusen, W.; Dobers, T.; Holler, Y. ...
IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States),
1992-Jan., 1992-01-00, 19920101, 1992-01-01, Letnik:
28, Številka:
1
Journal Article, Conference Proceeding
A measuring device was developed that is capable of determining the field parameters of a solenoid magnet by means of a precision Hall probe. The probe is sensitive to the three orthogonal field ...components and may be mounted either on a small trolley to run along or on a crank rotating around the axis of the magnet. This way the strength of the magnet as well as the lateral position of the magnetic axis with respect to the mechanical axis of the magnet may be determined. The measured value for the strength of the magnet meets the design value, while the position of the axis deviates considerably. If a second measurement, which is still to be done, confirms these findings, the construction and the alignment of the superconducting coil inside the cryostat will have to undergo a close examination.< >
In the hadron electron ring accelerator storage ring and its injection channels, a total of 454 dipoles, 716 quadrupoles, and 420 sextupoles of various types will be installed. The pole profiles of ...all magnet types have been designed with the aid of a computer program. Details are given of the devices developed to measure the fields of these magnets as well as the results of the measurements. All magnets were measured using the moving-coil technique. The coil length was chosen to be considerably longer than the iron yoke to include fringe fields and to get integrated values of the main and higher-order poles. On the basis of the statistical data extracted from the measurements carried out, it is concluded that the magnets to be installed will meet projected quality standards.< >
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