In the name of God the Beneficent the
In the name of God, the Beneficent the Merciful
Beam Dynamics Studies of the IPM Linac Shahin Sanaye Hajari, Saeed Haghtalab
Contents 1 Coupler asymmetry 1. 1 Induced kick 1. 2 Additional emittance growth 2 New buncher design 2. 1 The need for a new buncher 2. 2 Beam dynamics in a TW buncher 2. 3 New buncher 3 Solenoid Channel 3. 1 Review of the beam dynamics study results 3. 2 Final design 3. 3 Misalignment studies
Coupler asymmetry
1 Coupler asymmetry 1. 1 Induced kick 1
1 Coupler asymmetry 2 Beam cross section at the middle of the buncher Kick and emittance compensation using a dipole field ? ? ?
New buncher design
2 New buncher design 3
2 New buncher design 4 2. 2 Beam dynamics in a TW buncher Ø Longitudinal equation of motion in a TW structure: Principle wave amplitude RF phase seen by the particle Phase velocity Ø Synchronous particle & Motion of the nonsynchronous particle
2 New buncher design 2. 2 Beam dynamics in a TW buncher Ø Damped oscillatory motion Big The 5
2 New buncher design 6 2. 2 Beam dynamics in a TW buncher Ø Damped oscillatory motion Effective bunching: Beam acceleration & Field increase
2 New buncher design 2. 2 Beam dynamics in a TW buncher Ø Buncher design and optimization ü Adiabatic change of the structure 7
2 New buncher design 8 2. 2 Beam dynamics in a TW buncher Ø Buncher design and optimization ü Particle Tracking Ø Optimization criteria: ü To minimize the bunch length. ü To minimize the energy spread. ü To reach the required energy.
2 New buncher design 9 2. 2 Beam dynamics in a TW buncher Ø Buncher design and optimization ü Low initial electric field Larger phase acceptance Lower energy spread Lower emittance growth
2 New buncher design 10 2. 3 New buncher Ø Beam parameters and comparison with previous designs ü L = 40 cm (Pre-buncher included) Larger phase acceptance
2 New buncher design 2. 3 New buncher Ø Beam parameters and comparison with previous designs ü L = 50 cm (Pre-buncher included) 11
Solenoid Channel
3 Solenoid channel 12
3 Solenoid channel 13 Emittance Measurement
3 Solenoid channel 14
3 Solenoid channel 15
3 Solenoid channel 16
3 Solenoid channel Solenoid misalignments? 17
3 Solenoid channel 3. 3 Misalignment Studies Ø Focusing mechanism 18
3 Solenoid channel 3. 3 Misalignment Studies Ø Single particle trajectory 19
3 Solenoid channel 20
3 Solenoid channel 21
3 Solenoid channel 22 3. 3 Misalignment Studies Ø Offset
3 Solenoid channel 3. 3 Misalignment Studies Ø What to do? 1. Extend the strange buncher field sligthly more. Then the beam dynamics will be less sensitive to misalignments! 23
3 Solenoid channel 3. 3 Misalignment Studies Ø What to do? 2. Find the magnetic axis of the solenoid by measurement. 23
3 Solenoid channel 3. 3 Misalignment Studies Ø What to do? 2. Find the magnetic axis of the solenoid by measurement. 23
3 Solenoid channel 23 Beam position Measurement
Thanks for your attention!
- Slides: 34