1. PSB magnetic cycle 160 MeV to 2 GeV with 2.5E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 1 Requirements 1.Present performance: 1E13p from 50 MeV to 1.4 GeV in 490 ms (1.2s cycle) 2.New Goal: 2.5E13p from 160 MeV to 2 GeV in < 490 ms but still 1.2s cycle (less RMS current required in magnetic elements).

2. PSB magnetic cycle 160 MeV to 2 GeV with 2.5E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 2 BASIC CONSIDERATIONS 1.Only h1 cavity current capabilities considered for an h1 acceleration. The h2 cavity is considered as not participating to the acceleration (little h2 beam current with a rectangular bunch  π phase of h2 rf centered at φ S of h1) 2.8 kV considered as the maximum voltage on both h1 and h2 cavities. 3.Space charge effects due to faster acceleration not considered (shouldn’t be a worry anyhow) 4.Beam longitudinal emittance (4 sigma, h=1) with L2 -> 400 keV/600kHz=0.66 eV.s; with L4 -> 80% of 8kV injection bucket with 1.2T/s = 1.02 eV.s 5.Longitudinal blow-up (require more accelerating time due to higher emittance) and splitting (require flat-top) not considered.

3. PSB magnetic cycle 160 MeV to 2 GeV with 2.5E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 3 Approach Keep the longitudinal acceptance at least equal its value at injection with 8 kV and 1.2 T/s (due to a lack of time the analysis is made for a pure h=1 bucket). To be done for h1 + h2!).

4. PSB magnetic cycle 160 MeV to 2 GeV with 2.5E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 4 Simulation 1: injection at 1.2 T/s, bucket filled up to 80 % with 2.5E13p Only limitation = 8 kV on h1 cavity and acceptance kept at initial value. The acceleration lasts 310 ms (490 ms presently)

5. PSB magnetic cycle 160 MeV to 2 GeV with 2.5E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 5 Simulation 1: injection at 1.2 T/s, bucket filled up to 80 % with 2E13p Only limitation = 8 kV on h1 cavity and acceptance kept at initial value. The acceleration lasts 310 ms (490 ms presently)

6. PSB magnetic cycle 160 MeV to 2 GeV with 2.5E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 6 Simulation 2: injection at 1.2 T/s, bucket filled up to 80 % with 2.5E13p Limitations= 8 kV on h1 cavity, Bdot max = 28 G/ms. The acceleration lasts 380 ms (490 ms presently)

7. PSB magnetic cycle 160 MeV to 2 GeV with 2.5E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 7 Simulation 2: injection at 1.2 T/s, bucket filled up to 80 % with 2.5E13p Limitations= 8 kV on h1 cavity, Bdot max = 28 G/ms. The acceleration lasts 380 ms (490 ms presently)

8. PSB magnetic cycle 160 MeV to 2 GeV with 2.5E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 8 Simulation 3: injection at 1.2 T/s, bucket filled up to 80 % with 2.5E13p Limitations= 8 kV on h1 cavity, I C02 limited to 3A (acceleration current only). The acceleration lasts more than the present 490 ms (1.7 GeV reached after 530 ms (C805); we would need 100 ms more.

9. PSB magnetic cycle 160 MeV to 2 GeV with 2.5E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 9 Simulation 3: injection at 1.2 T/s, bucket filled up to 80 % with 2.5E13p Limitations= 8 kV on h1 cavity, I C02 limited to 3A (acceleration current only). The acceleration lasts more than the present 490 ms (1.7 GeV reached after 530 ms (C805); we would need 100 ms more.

10. PSB magnetic cycle 160 MeV to 2 GeV with 2.0E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 10 Simulation 4: injection at 1.2 T/s, bucket filled up to 80 % with 2.0E13p Limitations= 8 kV on h1 cavity, I C02 limited to 3A (available acceleration current). The acceleration lasts 530 ms (490 ms at present) No more flat-top

11. PSB magnetic cycle 160 MeV to 2 GeV with 2.0E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 11 Simulation 4: injection at 2 T/s, bucket filled up to 80 % with 2.0E13p Limitations= 8 kV on h1 cavity, I C02 limited to 3A (available acceleration current). The acceleration lasts 530 ms (490 ms at present) No more flat-top

12. PSB magnetic cycle 160 MeV to 2 GeV with 2.5E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 12 Preliminary conclusion: The C02 cavity current is the main limiting parameter 3A are available for acceleration and tuning errors induced effects => should be more than 6 A (for 2.5E13p) The present maximum Bdot is ok for a 380 ms acceleration duration with 2.5E13p Simulations showing that we could accelerate 2E13p with a zero flat-top and the present C02 available current are very theoretical (no margin for tuning loop errors induced effects and tube ageing) These simulations need to be refined to take into account the real h1+h2 acceleration parameters (pure h1 approximation here), the bunch shape distortion due to asymmetrical accelerating bucket, the adiabaticity (around extraction), the limit of rf beam loading instability…)

13. PSB magnetic cycle 50 MeV to 2 GeV with 1.0E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 13 Simulation 5: inj. at 50 MeV, 0.5 T/s (current L2 value), beam emittance = 0.66 eV.s, 1.0E13p. Limitations: 8 kV on h1 cavity, I C02 limited to 2A (1A margin), Bdot limited to 26 G/ms. The acceleration lasts 490 ms (same as with 1.4 GeV)

14. PSB magnetic cycle 50 MeV to 2 GeV with 1.0E13 protons per ring A. Blas 2 GeV magnetic cycle 29/04/2010 14 The acceleration lasts 490 ms (same as with 1.4 GeV) Simulation 5: inj. at 50 MeV, 0.5 T/s (current L2 value), beam emittance = 0.66 eV.s, 1.0E13p. Limitations: 8 kV on h1 cavity, I C02 limited to 2A (1A margin), Bdot limited to 26 G/ms.