Design of a Low-Energy Chopper System for FRANZ

Transcription

1 Design of a Low-Energy System for FRANZ Christoph Wiesner

2 Contents Introduction Design and Layout of the Multi-Particle Simulation LEBT Outlook

3 Function of the Input: 150 ma cw proton beam, 120 kev Output: ns bunches, repetition rate f = 250 khz LEBT- 150 kv Terminal W b = 120 kev 4 P = 2.4 x 10 W b W b = 1 MeV 4 P b,max = 1 x 10 W Steerer W b = MeV 4 P b,max = 2.1 x 10 W Rebuncher Strahlstopper Detektor- und Komponententeststand Dipolmagnet Ionenquelle t = ns f = 250kHz RFQ Rebuncher CH f = 5-10MHz Bunchkompressor 7 Li Target

4 Possible s Types Disc Electrical Magnetic with Helmholtz Coils Dipole System

5 Functional Principle of the Dipole System Beam Diagnostics Dipole Magnet f = 250 khz τ= ns Resonant Circuit High Current Proton Storage Ring

6 Functional Principle of the Dipole System Aperture time 1,0 Varying the aperture leads to different bunch lengths and intensities. Transmission / % 0,8 0,6 0,4 0, t / ns

7 Layout Dipole System Beam Diagnostics Parameter Setting: Dipole Magnet B max = 0.3 T Dipole Length = 0.3 m f = 250 khz τ= ns Total System Length = 0.6 m Resonant Circuit 0.3m High Current Proton Storage Ring Gap Height = 0.06 m 0.6m B( t) = Bmax sin( ωt + Φn)

8 Layout LEBT Beam Diagnostics Dipole Magnet f = 250 khz τ= ns Resonant Circuit High Current Proton Storage Ring LEBT Solenoid 1: Aperture 150mm 150 kv Terminal W b = 120 kev 4 P = 2.4 x 10 W b W b = 1 MeV 4 P b,max = 1 x 10 W Steerer W b = MeV 4 P b,max = 2.1 x 10 W Rebuncher Solenoid 2-4: Aperture 100mm Strahlstopper Detektor- und Komponententeststand Dipolmagnet Ionenquelle t = ns f = 250kHz RFQ Rebuncher CH f = 5-10MHz Bunchkompressor 7 Li Target

9 Schematic View of LEBT

10 Schematic View of LEBT Beam Envelope

11 Schematic View of LEBT Simulation Programs used: Lintrafive (Sek1, Sek3) DipMag (Dipole)

12 Input Distribution 60 Solenoid 1 Solenoid 2 Solenoid 3 Solenoid 4 50 Strahlradius r [mm] Start Parameters Ion Source Beam Radius: 6 mm Divergence Angle: 80 mrad Homogeneous Distribution (Assumed) Dipol ausgeschaltet Dipol eingeschaltet

13 Phase Distribution in front of Dipole 60 Solenoid 1 Solenoid 2 Solenoid 3 Solenoid 4 50 Strahlradius r [mm] Dipol ausgeschaltet Dipol eingeschaltet

14 Simulation Dipole System 60 Solenoid 1 Solenoid 2 Solenoid 3 Solenoid 4 50 Strahlradius r [mm] Dipol ausgeschaltet Dipol eingeschaltet

15 Phase Distribution behind Slit B max (Dipole)= 0.2 T 60 Solenoid 1 Solenoid 2 Solenoid 3 Solenoid 4 50 Strahlradius r [mm] Dipol ausgeschaltet Dipol eingeschaltet

16 60 Solenoid 1 Solenoid 2 Solenoid 3 Solenoid 4 50 Strahlradius r [mm] Dipol ausgeschaltet Dipol eingeschaltet

17 creates different beam distribution (depending on direction of Magnetic Field). Spatial Distribution in front of RFQ 60 Solenoid 1 Solenoid 2 Solenoid 3 Solenoid 4 50 Strahlradius r [mm] Dipol ausgeschaltet Dipol eingeschaltet

18 Phase Distribution in front of RFQ

19 Phase Distribution in front of RFQ - 3d 1,0 Transmission / % 0,8 0,6 0,4 0, t / ns

20 Outlook: To Do? Multi-Particle Simulations Beam Dynamics in LEBT Variation of Parameters Beam Dynamics in Variation of Parameters Emittance Growth Estimations Simulations for H 2+ and H 3 + Layout Fix Geometry of Begin Construction Vacuum Chamber Technical Implementation Choose Type of Dipole Choose Magnetic Material Design Electronic Control