merit beam spot from optics (update of july 16,2008 talk)
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MERIT beam spot from optics (update of July 16,2008 talk). I.Efthymiopoulos – CERN, AB Dept. MERIT, VRVS Meeting September 25, 2008. MERIT Elements – Layout. QDE.430s (de-focusing) quads 3 elements in series. QFO.415s (focusing) quads 3 elements in series. - PowerPoint PPT PresentationTRANSCRIPT
MERIT beam spot from optics (update of July 16,2008 talk)
I.Efthymiopoulos – CERN, AB Dept.
MERIT, VRVS MeetingSeptember 25, 2008
2September 25, 2008
MERIT Elements – Layout
QFO.415s (focusing) quads3 elements in series
QDE.430s (de-focusing) quads3 elements in series
3
Survey data after the MERIT run – 18.12.2007
September 25, 2008
Upstream face: -72.3cm
4
Beam optics
Fit parameters: QFO, QDO strengths and locations (within limits)
September 25, 2008
5
Beam envelope (1-sigma) - =0.25 (mm.mrad), Dp=0.1%
September 25, 2008
Without dispersion term s(x) = 1.2mm , s(y) = 1.1 mm 238 J/gr @ 30TP
With dispersion term s(x) = 2.2mm , s(y) = 1.1 mm 130 J/gr @ 30TP
6September 25, 2008
Reminder – Beam Emittance
For proton machines, the emittance is measured by measuring the beam profile in a position of known beam parameters (optics) The convention is to use TWO sigma value
s
2 s
Emittance (87% of beam)
s
2)2(protons
Geometrical emittance: Normalized emittance:
0
0* ,)(MP
P [GeV/c]
()
14.0 14.92
24.0 25.58
2
ppDp
s
Including dispersion What is measured in the machine:
s
s
s
ss
2
2
24
22
2
),widthfitted4(
ppDw
ppf
p
7September 25, 2008
Beam Emittance measurement – 14 GeV/c
Friday 26.10@15:55Beam intensity: h16, 1E13
8September 25, 2008
Beam Emittance measurement – 14 GeV/c
Friday 26.10@17:37Beam intensity: 2.5E11/bunch 2 extracted bunches, DT=1.7us
9September 25, 2008
Beam Emittance measurement – 14 GeV/c
Friday 26.10@18:24Beam intensity: 1.3E12/bunch 2 extracted bunches, DT=1.7us
10September 25, 2008
Beam Emittance measurement – 24 GeV/c
Friday 02.11@14:55PMBeam intensity: 2.5E11/bunch 16 bunches
11September 25, 2008
Beam Emittance measurement – 24 GeV/c
Friday 02.11@16:02PMBeam intensity: 16 bunches, 6E12 protons
12
Beam Emittance measurement
Summary of measured data
September 25, 2008
Using the formulas of slide #6
in good agreement with the online calculations
13
Emittance extrapolation
0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.20000.000
2.000
4.000
6.000
8.000
10.000
12.000
14.000
16.000
18.000
f(x) = 6.16979686790305 x + 5.40191943831546R² = 0.645376915439818
f(x) = 10.8126253784677 x + 2.1946797337666R² = 0.687940286488453
Transverse emittance (2s) in TT2
MERIT-Eh Linear (MERIT-Eh)
MERIT-Ev Linear (MERIT-Ev)
Beam intensity (1E13)
Eh &
Ev
[nor
m]
September 25, 2008
14
Estimated beam spot and density
Use the extrapolated emittances to estimate the beam spot and energy density at target
September 25, 2008