MERIT beam spot from optics (update of July 16,2008 talk)

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