PowerPoint Presentation

							Combine-Function Magnet
    V. Kashikhin for EMMA Workshop
               July 2, 2006
                                    Magnet Parameters


            The proposed combined function magnet has C-type iron yoke and
             separate dipole and quadrupole windings. Each winding powered from
             individual power supply. They can be connected in series in accelerator
             ring. Dipole component of magnetic field formed by parallel surfaces of
             iron poles.     Quadrupole field component formed by sectional
             quadrupole winding placed into the pole slots. Such configuration
             provides independent regulation both field components.
                                    Magnet parameters
                Magnet configuration                                  C- type
                Dipole field                                         0.15 T
                Adjustable quadrupole gradient                         0 – 6.8 T/m
                Dipole winding ampere-turns                           7600 A
                Quadrupole pole winding ampere-turns                   11638 A
                Magnet effective length                              50 mm



                                                                        V.Kashikhin
Meeting Daresbury, 1-2 July, 2006                                                 2
                                    Magnetic Design




                                                      V.Kashikhin
Meeting Daresbury, 1-2 July, 2006                               3
                                    Flux Density in the Yoke




                                                               V.Kashikhin
Meeting Daresbury, 1-2 July, 2006                                        4
                                    Field Distribution




   Field homogeneity in the magnet middle plane at dipole current
   7600 A and quadrupole total currents: 5622A, 2811A, 1405 A.
                                                         V.Kashikhin
Meeting Daresbury, 1-2 July, 2006                                  5
                                    Design Issues

         1. Combined Dipole plus Quadrupole
         2. Independent Dipole and Quadrupole field
            regulations
         3. Field quality in wide range of field changes
         4. Open from side air gap for beam pipe
            installation, pumps, etc.
         5. Short 5 cm magnet length
         6. End fields
         7. Quadrupole coil cooling
                                                      V.Kashikhin
Meeting Daresbury, 1-2 July, 2006                               6
                                    Summary


Proposed version of magnet capable generate the specified
field levels. The main issues which should be investigated:
Coil cooling. Rather high average current density ~9
A/mm2. Should be used water cooling or average power
dissipation should be regulated by current duty cycle. It
looks, 4-8 sec cycles will be acceptable.
Field quality deviations during gradient change. Should be
compensated the pole and slots optimization.
End fields and corresponding field distortions should be
compensated by proper ends design.

                                                 V.Kashikhin
Meeting Daresbury, 1-2 July, 2006                          7