1. Beam load estimates for the PS2 Beam Dump Systems T. Kramer, M. Benedikt, B. Goddard

2. 24.10.2007 T. Kramer AB-BT-TL2 Main PS2 design parameters and key assumptions for the dump load calculations Assumed 200 days of operation Maximum of 1.08 x 10 21 protons /y All calculations are done in a rather conservative way Injection energy (T)GeV4 Extraction energy (T)GeV50 Maximum beam intensity p+p+ 1.5  10 14 Minimum cycle period to 50 GeVs2.4 Maximum norm.emittance (H-V) .mm.mrad 15.0-8.0 Cycles per year7.200,000 Protons accelerated per year p+p+ 1.08  10 21

3. 24.10.2007 T. Kramer AB-BT-TL3 Dump functionalities Injection line setting up Fast injection setting up H- Injection Emergency abort Machine development Machine setting up Extraction line setting up Slow extraction ‘remaining beam’

4. 24.10.2007 T. Kramer AB-BT-TL4 H- Injection 6.4x10 19 p.a. (5.92%) @ 4 GeV details later…. Emergency beam abort assumed 0.5% of cycles dumped 5.4x10 18 (0.5%) particles p.a. (50% @ 4-20 GeV) Machine setting up 6 days (2 per beam); 20% of full intensity 6.5x10 18 p.a. (0.6%) (50% @ 4-20GeV) Machine development 100h p.a. 20% of full intensity 4.3x10 18 p.a. (0.4%) (50% @ 4-20 GeV) Particles remaining after slow extraction Max. 1 % remaining particles; 50 GeV; operational 50% p.a.; 3.6s cycle 3.6x10 18 p.a. (0.33%) Fast injection setting up and failures 1 day p.a.; 20% dumped; 100 failures p.a. 1.08x10 18 p.a. (0.1%) @ 4 GeV Setting up of injection transfer line 4 days p.a.; 10% intensity; 20 foil exchange interventions; 3.06x10 18 p.a. (0.28%) @ 4 GeV Setting up of extraction transfer line 2 days p.a.; 30% intensity; 3.25x10 18 p.a. (0.3%) @ 50 GeV

5. 24.10.2007 T. Kramer AB-BT-TL5 Summary of beam loads FunctionE [GeV]Load [p + ] % of total Possible beam destinations Injection transfer line dump Internal fast injection dump Internal or external H - dump Internal or external emergency dump Injection line setting up43.1x10 18 0.28X Fast injection setting up41.1x10 18 0.10X H - injection losses46.4x10 19 5.92X Emergency abort4-202.7x10 18 0.25X Machine development4-202.2x10 18 0.20X Machine setting up4-203.3x10 18 0.30X FunctionE [GeV]Load [p + ]% of total Possible beam destinations Internal or external emergency dump External beamline or transfer line dump Emergency abort20-502.7x10 18 0.25X Machine development20-502.2x10 18 0.20XX Machine setting up20-503.3x10 18 0.30XX Extraction line setting up503.3x10 18 0.30 X Slow extraction beam503.6x10 18 0.33XX Table 1: Beam loads @ “high Energy” Table 2: Beam loads @ “low Energy”

6. 24.10.2007 T. Kramer AB-BT-TL6 External beam line dump PS2 extraction line dump TED External H- injection dump PS2 injection transfer line dump TED(s) Internal fast injection dump Internal emergency dump ? ? SPS TT12 EAs PS2 TT10 from SPL Schematic overview

7. 24.10.2007 T. Kramer AB-BT-TL7 Unstripped beam 2 kW unstripped H -,H 0 (5% efficiency) 5.4x10 19 p.a. (5%) Yearly startup 8x10 18 p.a. (0.75%) Setting up Injection systems / foil exchange 1.8x10 18 p.a. (0.16%) H - Injection - Beam Loads

8. 24.10.2007 T. Kramer AB-BT-TL8 H - Injection - extract beam back to TT10 Overview of PS2 H-Injection; B. Goddard; PS2 meeting; 05/2007

9. 24.10.2007 T. Kramer AB-BT-TL9 H - Injection - Factors of Influence Stripping efficiency Emittance dilution Foil heating To be considered: Lorentz Stripping H0 excited states Stripping efficiency Beam blow up Lifetime Temperature Foil thickness Beam load H 0 /H - Foil material Size, activation, position of the beam dump 5%5% <0,1 pi mm mrad Losses! Some optimization should be possible - studies

10. 24.10.2007 T. Kramer AB-BT-TL10 Internal emergency dump Possible solution (as proposed): Internal dump only takes the beam which really has to go there (8x10 18 4-20 GeV + 2.7x10 18 p@50 GeV p.a.) Whenever there is time to extract the beam safely a beam line dump is used (slow extraction, machine development. 5.5x10 18 @ 20-50 GeV + 6.9x10 18 @ 50GeV p.a. ) External dump at end of beamline in well-shielded EA zone? Advantages System is easier to build, cheaper, desirable from point of operations, “some internal dump” to set up the extraction is anyway needed Disadvantage For operations like in the SPS a very high beam load is expected - Radiation source within the machine

11. 24.10.2007 T. Kramer AB-BT-TL11 Summary of loads and issues PS2 dump Beam loads [p + /y] 4 GeV4-20 GeV20-50 GeV50 GeV 1. PS2 injection transfer line dump3.1x10 18 --- 2. Internal fast injection dump1.1x10 18 --- 3. External H - injection dump6.4x10 19 --- 4. Internal emergency dump-8.2x10 18 2.7x10 18 - 5. External beamline dump--5.5x10 18 6.9x10 18 Issues Need for TEDs/beam stoppers at the end of transfer lines…including for ions and p+ from PSB before SPL comes on line. Configuration for injection and extraction region….becoming congested. Extraction and dumping of unstripped H - beam (acceptance, losses, …) Optimization of losses for H - injection? Studies need to be done… Conservative calculation to keep the highest degree of freedom; If we have serious problems concerning feasibility (costs) we have to define more accurate operations and design parameters and look into detail again.