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THE ESS LINAC
HS_2011_11_23
Mohammad Eshraqi 8 December 2011
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1 THE ESS LINAC HS_2011_11_23 Mohammad Eshraqi 8 December 2011 2 - - PowerPoint PPT Presentation
1 THE ESS LINAC HS_2011_11_23 Mohammad Eshraqi 8 December 2011 2 - - PowerPoint PPT Presentation
1 THE ESS LINAC HS_2011_11_23 Mohammad Eshraqi 8 December 2011 2 ESS Power: 5 MW Energy: 2.5 GeV Current: 50 mA Repetition rate: 14 Hz Duty cycle: 4% Ions: p 3 M. Eshraqi | 8-December-2011 | SLHiPP -CERN ESS
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SLIDE 3
- M. Eshraqi | 8-December-2011 | SLHiPP -CERN
ESS
- Power: 5 MW
- Energy: 2.5 GeV
- Current: 50 mA
- Repetition rate: 14 Hz
- Duty cycle: 4%
- Ions: p
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SLIDE 4
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
ESS LINAC
HS_2011_11_23
Spokes Low β High β DTL MEBT RFQ LEBT Source HEBT & Upgrade Target
2.1 m 5 m 1.0 m 19 m 75 m 117 m 200 m 100 m
75 keV 3 MeV 50 MeV 191 MeV 653 MeV 2500 MeV
352.21 MHz 704.42 MHz
Energy (MeV) No. of Modules No. of Cavities βg Temp (K) Cryo Length (m)
Source
0.075 1 – ~300 –
LEBT
0.075 – – ~300 –
RFQ
3 1 1 – ~300 –
MEBT
3 – 2 – ~300 –
DTL
50 3 3 – ~300 –
Spoke
191 18 2 × 18 0.46 βopt ~2 3.67
Low β
653 16 4 × 16 0.70 ~2 6.80
High β
2500 14 8 × 14 0.92 ~2 13.81
HEBT
2500 – – ~300 –
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SLIDE 5
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
CRYOMODULE
- Lperiod = Lcryo + 500 mm
For exact lengths visit:
http://esss.se/linac/Parameters/pdf/Cryomodules%20Spoke.pdf http://esss.se/linac/Parameters/pdf/Cryomodules%20Low%20beta.pdf http://esss.se/linac/Parameters/pdf/Cryomodules%20High%20beta.pdf
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- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
CRYOMODULE ?
- Lperiod = Lcryo + 500 mm
Warm quads? Could save ~30 m in length
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SLIDE 7
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
PHASE ADVANCE
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SLIDE 8
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
RESONANCES
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- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
ENVELOPES
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SLIDE 10
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
DENSITY
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- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
EMITTANCE
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- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
EMITTANCE
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SLIDE 13
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
- AVE. PHASE ADVANCE
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- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
DTL II
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- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
A REMEDY?
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5 10 15 20 25 30 35 L (m) 50 55 60 65 70 75 80 85 90 Wout (MeV) DTL Wout Spokes Win DTL-5 Spokes-3 DTL-4 Spokes-5 Spokes-4 Spokes-2 Spokes-6 45 55 65 75 85 95 105 115 125 135 145 155 W(MeV) 6 8 10 12 14 16 18 20 22 24 26 k0l (°/m) DTL k0lout Spokes k0lin Spokes DTL 4 5 11 9 7 5 3 1
Courtesy of James Stovall Reducing the number of spoke cavities/cryomodule from 3 to 2 increased the kol to ~18 deg/m.
SLIDE 16
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
QUAD ERROR FODO
Δx = Δy = 0.1 mm, ΔG= 0.5% Δεx = 25±12 Δεy = 20±10 Δεz = 34±18
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SLIDE 17
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
QUAD ERROR FODO
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SLIDE 18
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
CAVITY MISALIGNMENT
Δx = Δy = 0.5 mm Δεx = 0.42±0.26 Δεy = 0.16±0.18 Δεz = 0.28±0.27
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- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
CAVITY MISALIGNMENT
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SLIDE 20
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
QUAD ERROR FFDD
Δx = Δy = 0.1 mm, ΔG= 0.5% Δεx = 22±11 Δεy = 20±9 Δεz = 34±18
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SLIDE 21
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
QUAD ERROR FFDD
FFDD
FFDD21
SLIDE 22
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
BRANCHING
Spokes Low β High β DTL MEBT RFQ LEBT Source HEBT & Upgrade Target
2.1 m 5 m 1.0 m 19 m 75 m 117 m 200 m 100 m
75 keV 3 MeV 50 MeV 191 MeV 653 MeV 2500 MeV
352.21 MHz 704.42 MHz
A 2.4 m, 1 T dipole is enough to divert the beam by 32 deg at 650 MeV, plus 2.7 m or , 2.16 m for the quadrupoles. Leaving one period respects the periodicity and provides space to extract the beam using NC dipoles.
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- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
SUMMARY AND FURTHER STUDIES
The discontinuity in the average phase advance causes emittance increase in transition between RFQ-MEBT, MEBT-DTL, and DTL-Spoke. The current baseline uses a FoDo lattice in the DTL, however, an FFDD lattice would cause less losses in the spokes in cases of errors. Alignment precision of 0.1 mm and 0.5% gradient error results in losses within the limit in the FFDD DTL. Quad error in the SC linac is left to be studied, although the same error as in DTL caused no extra losses in SC linac.
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- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
THANK YOU!
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SLIDE 25
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SLIDE 26
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
!" #!!" $!!" %!!" &!!" '!!" (!!" )!!" *!!" +!!" #!!!" !" '!" #!!" #'!" $!!" $'!" %!!" %'!" &!!" !"#$%&'$%&()*+,-&./01& !"2+3"4&.51& ,"-./0"123.45" ,"-./0"637"849:" ,"-;/0"<=>?"849:"
POWER PER CAVITY
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- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
PHASES
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SLIDE 28
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
INTEGRATED GRADIENT
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SLIDE 29
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
FIELD AND TTF IN SPOKE
!"#$% !"$$% !#$% $% #$% "$$% "#$% $% $&'% $&(% $&)% $&*% "% "&'% +,-.%/0''1% 23445-%/("'1% 267%/0$81% !"!!# !"$!# !"%!# !"&!# !"'!# !"(!# !")!# !"*!# !"+!# !",!# !"&$# !"&)# !"'$# !"')# !"($# !"()# !")$#- ./0#
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SLIDE 30
- M. Eshraqi | 8-December-2011 | SLHiPP - CERN
DTL
- The DTL is designed, for the moment, as one RF tank and there are 2
different focusing schemes used, FFDD and FoDo.
- Each of these designs have two settings for the gradients, one “Constant
Gradient” and one “equipartitioned”. The DTL is designed by Michele Comunian
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