beam load estimates for the ps2 beam dump systems t. kramer, m. benedikt, b. goddard

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

24.10.2007 T. Kramer AB-BT-TL 2

Main PS2 design parameters and key assumptions for the dump load calculations

Assumed 200 days of operation

Maximum of 1.08 x 1021 protons /y

All calculations are done in a rather conservative way

Injection energy (T) GeV 4

Extraction energy (T) GeV 50

Maximum beam intensity p+ 1.51014

Minimum cycle period to 50 GeV s 2.4

Maximum norm.emittance (H-V) .mm.mrad 15.0-8.0

Cycles per year 7.200,000

Protons accelerated per year p+ 1.081021


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’


H- Injection 6.4x1019 p.a. (5.92%) @ 4 GeV details later….

Emergency beam abort assumed 0.5% of cycles dumped 5.4x1018 (0.5%) particles p.a. (50% @ 4-20 GeV)

Machine setting up 6 days (2 per beam); 20% of full intensity 6.5x1018 p.a. (0.6%) (50% @ 4-20GeV)

Machine development 100h p.a. 20% of full intensity 4.3x1018 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 3.6x1018 p.a. (0.33%)

Fast injection setting up and failures 1 day p.a.; 20% dumped; 100 failures p.a. 1.08x1018 p.a. (0.1%) @ 4 GeV

Setting up of injection transfer line 4 days p.a.; 10% intensity; 20 foil exchange interventions; 3.06x1018 p.a. (0.28%) @ 4 GeV

Setting up of extraction transfer line 2 days p.a.; 30% intensity; 3.25x1018 p.a. (0.3%) @ 50 GeV


Summary of beam loads

Function E [GeV] Load [p+]% oftotal

Possible beam destinations

Injection transfer

line dump

Internal fast injection

dump

Internal or external H- dump

Internal or external

emergency dump

Injection line setting up 4 3.1x1018 0.28 X

Fast injection setting up 4 1.1x1018 0.10 X

H- injection losses 4 6.4x1019 5.92 X

Emergency abort 4-20 2.7x1018 0.25 X

Machine development 4-20 2.2x1018 0.20 X

Machine setting up 4-20 3.3x1018 0.30 X

Function E [GeV] Load [p+] % of total

Possible beam destinations

Internal or external emergency dump

External beamline or transfer line dump

Emergency abort 20-50 2.7x1018 0.25 X

Machine development 20-50 2.2x1018 0.20 X X

Machine setting up 20-50 3.3x1018 0.30 X X

Extraction line setting up 50 3.3x1018 0.30 X

Slow extraction beam 50 3.6x1018 0.33 X X

Table 1: Beam loads @ “high Energy”

Table 2: Beam loads @ “low Energy”


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


Unstripped beam 2 kW unstripped H-,H0 (5% efficiency) 5.4x1019 p.a. (5%)

Yearly startup 8x1018 p.a. (0.75%)

Setting up Injection systems / foil exchange 1.8x1018 p.a. (0.16%)

H- Injection - Beam Loads


H- Injection - extract beam back to TT10

Overview of PS2 H-Injection; B. Goddard; PS2 meeting; 05/2007


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 loadH0/H-

Foil material

Size, activation, positionof the beam dump

5%

<0,1 pi mm mrad

Losses!

Some optimization should be possible - studies


Internal emergency dump

Possible solution (as proposed):

Internal dump only takes the beam which really has to go there (8x1018 4-20 GeV + 2.7x1018 p@50 GeV p.a.)

Whenever there is time to extract the beam safely a beam line dump is used (slow extraction, machine development. 5.5x1018 @ 20-50 GeV + 6.9x1018 @ 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


Summary of loads and issues

PS2 dumpBeam loads [p+ /y]

4 GeV 4-20 GeV 20-50 GeV 50 GeV

1. PS2 injection transfer line dump 3.1x1018 - - -

2. Internal fast injection dump 1.1x1018 - - -

3. External H- injection dump 6.4x1019 - - -

4. Internal emergency dump - 8.2x1018 2.7x1018 -

5. External beamline dump - - 5.5x1018 6.9x1018

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.

beam load estimates for the ps2 beam dump systems t. kramer, m. benedikt, b. goddard

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