brain gestorme: status of the lhec ring-ring / linac- ring basic parameters i appologise to talk...
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Brain Gestorme: Status of the Brain Gestorme: Status of the LHeC Ring-Ring / Linac-LHeC Ring-Ring / Linac-
Ring Basic ParametersRing Basic Parameters
I appologise to talk about things you already know ...
Design Parameterselectron beam RR LR ERL LRe- energy at IP[GeV] 60 60 140luminosity [1032 cm-2s-1] 17 10 0.44polarization [%] 40 90 90bunch population [109] 26 2.0 1.6e- bunch length [mm] 10 0.3 0.3bunch interval [ns] 25 50 50transv. emit. x,y [mm] 0.58, 0.29 0.05 0.1
rms IP beam size x,y [m] 30, 16 7 7
e- IP beta funct. *x,y [m] 0.18, 0.10 0.12 0.14
full crossing angle [mrad] 0.93 0 0geometric reduction Hhg 0.77 0.91 0.94
repetition rate [Hz] N/A N/A 10beam pulse length [ms] N/A N/A 5ER efficiency N/A 94% N/Aaverage current [mA] 131 6.6 5.4tot. wall plug power[MW] 100 100 100
proton beam RR LRbunch pop. [1011] 1.7 1.7tr.emit.x,y [m] 3.75 3.75
spot size x,y [m] 30, 16 7
*x,y [m] 1.8,0.5 0.1$
bunch spacing [ns] 25 25
$ smaller LR p-* value than for nominal LHC (0.55 m):
- reduced l* (23 → 10 m)- only one p beam squeezed- IR quads as for HL-LHC
RR= Ring – RingLR =Linac –RingERL=energy recovery linac
Tentative: 8.7.2010
Change in Electron Energy: 70 GeV 60 GeVBeam Emittance
again requiring:
What do we gain in this case ?relaxed separation scheme (dominated by e-emittance)smaller crossing angle !!!
keeping cool … i.e. keep σe constrelax the electron optics
the crossing angle: in the end the source of many problems
First parasitic crossing: s = 3.75m
F. Willeke
βx
€
ex = 5.0 nm
εey = 2.5 nm
Separation: 5σp + 5σe =0.35mm+ 5mm ≈5.5 mm
X-angle ≈ 1.4 mrad
the crossing angle: in the end the source of many problems
First parasitic crossing: s = 3.75m
F. Willeke
βx
Separation:
sc half quadrupole: g = 127 T/mfield free region (e-beam) ≈ Gaussseparation required ≈ 50 mm
Beam Separation at first p – Quadrupole: ... a technical problem
S. Russenschuck
sc quadrupole Q2: field free region (e-beam) ≈ Gaussseparation required ≈ 85 mm
Beam Separation at second p – Quadrupole:
S. Russenschuck
complete the electron ring latticeinclude the IR into Miriams Arc / Dispersion suppressor geometry
match the electron ring optics from β* to the periodic solution for 1 & 10 degree option
determine βmax at first parasitic encounterre-iterate the separation scheme-> recalculate the synchrotron light-> input for Nathan: Absorber Geometry
write report
Further Plans:
status e-optics for IPAC 2010
Design Parameterselectron beam RR LR ERL LRe- energy at IP[GeV] 60 60 140luminosity [1032 cm-2s-1] 17 10 0.44polarization [%] 40 90 90bunch population [109] 26 2.0 1.6e- bunch length [mm] 10 0.3 0.3bunch interval [ns] 25 50 50transv. emit. x,y [mm] 0.58, 0.29 0.05 0.1
rms IP beam size x,y [m] 30, 16 7 7
e- IP beta funct. *x,y [m] 0.18, 0.10 0.12 0.14
full crossing angle [mrad] 0.93 0 0geometric reduction Hhg 0.77 0.91 0.94
repetition rate [Hz] N/A N/A 10beam pulse length [ms] N/A N/A 5ER efficiency N/A 94% N/Aaverage current [mA] 131 6.6 5.4tot. wall plug power[MW] 100 100 100
proton beam RR LRbunch pop. [1011] 1.7 1.7tr.emit.x,y [m] 3.75 3.75
spot size x,y [m] 30, 16 7
*x,y [m] 1.8,0.5 0.1$
bunch spacing [ns] 25 25
$ smaller LR p-* value than for nominal LHC (0.55 m):
- reduced l* (23 → 10 m)- only one p beam squeezed- IR quads as for HL-LHC
RR= Ring – RingLR =Linac –RingERL=energy recovery linac
Tentative: 8.7.2010
IR principles for a LR Design (R.T.) The proton IP beta function is pushed down to 10
cm and head-on collisions are achieved via an IR dipole.In order to keep the proton triplet chromaticity to an acceptable level the l* (distance from IP to first quadrupole) has to be reduced from 23m (LHC nominal) to 10m.It is proposed to create a separating dipole field already very close to the IP, being embedded in the Solenoid design of the particle detector.
βp=10 cml*= 10 m
“It was proposed to do a new "toy" design to get to the level of 200 keV and compare the results.”