1. Status on Work for Splitter FS and Dilution System FS
Christoph Hessler
TT20 for BDF Meeting 06/03/2017

2. Assumed Beam Parameters
Value
Energy (GeV)
400
Norm. horizontal emittance (μm)
14.9
Norm. vertical emittance (μm)
14.2
Phys. horizontal emittance (m)
e-08
Phys. vertical emittance (m)
e-08
Beta_x (m)
Beta_y (m)
Alpha_x
Alpha_y
Mu_x
Mu_y
D_x
DP_x
D_y
0.289
DP_y
From tracking
simulations
From official
optics
06 March 2017
C. Hessler

3. Present Optics for TT20
2016 optics for TT20 (T2) as found on /afs/cern.ch/eng/ps/cps/TransLines/TT20/2016
Beta function for other targets even higher. → Are these optics really used in practice?
06 March 2017
C. Hessler

4. Preliminary Beam Line Design (I)
Preliminary beam line design by Brennan Goddard and Matthew Fraser:
17 new MBBs, 5 new quadrupoles
Dispersion suppression scheme
06 March 2017
C. Hessler

5. Beam Optics (I) Beam matched to 10 mm sigma at the target
Dispersion well suppressed
06 March 2017
C. Hessler

6. Aperture (I) But: Partially only 2 sigma aperture! 06 March 2017
C. Hessler

7. Preliminary Beam Line Design (II)
5 new MBBs, 18 new MBNs, 6 new quadrupoles.
Beam from SPS matched to the FODO structure of the beam line.
Beam matched to the FODO structure of the new part of the line.
Beam not yet matched to the target
Dispersion not yet suppressed at target.
Work in progress
06 March 2017
C. Hessler

8. Aperture (II)
Now there are some problems in the existing part of the line, but not as severe.
More optimization needed.
06 March 2017
C. Hessler

9. Aperture studies for splitting magnet
Based on Matthew’s preliminary beam line design
Beam envelope (6 sigma) and the position of the beam deflected by 8.2 mrad in total calculated in the enlarged MSSB.
Error distributions for quadrupole alignment errors, main dipole field and tilt errors and injection errors added and beam coordinates for 1000 random values of these error distributions calculated.
In the attached pictures you can see the cross section at the start of the 1st splitter magnet, after each splitter magnet and after BTV Each trajectory shows a red spot (not really visible) surrounded by an ellipse defining the 6 sigma beam radius. The green spot and ellipse is the non-deflected beam. The beam direction is out of the plane. By averaging over all trajectories I got the following values for the transverse position of the beam centre:
06 March 2017
C. Hessler

10. Aperture studies for splitting magnet
<x>= 0.08 mm
<x>= 6.51 mm
<x>= mm
<x>= mm
<x>= mm
06 March 2017
C. Hessler

11. Next Steps
Survey matching to the good target position → Where is it? CCS coordinates?
Using good beam parameters.
Match beam to the target
Dispersion suppression.
Get aperture problem fixed.
Add dilution kickers. → Which magnet type? Proposal MPLH/MPLV.
06 March 2017
C. Hessler