1. MD Studies for LIU PS Injection
M. Serluca, W. Bartmann, V. Forte, G. Sterbini
MSWG, 02 September 2016

2. Motivation
Optics studies on the transfer line and PS ring for the future injection at 2 GeV have shown that the optimized septum position is 1 cm closer to the PS closed orbit with respect the actual position
MD goal: verify that the future septum position is compatible with LIU requirements for 2 GeV beams type and PPM compatibility with beam at 1.4 GeV

3. Present injection region SS42
ACEM BLM42
Diamond BLM42
Injection line from PSB
MU 41
MU 42
BLMs on the top of MU42
BSW42
SMH42
BEAM

4. Future injection region
Eddy current septum
New septum-bumper 42 (same vacuum vessel)
BEAM
MU 41
MU 42
35 cm septum-like
bumper

5. Future injection area
Example of injection of 2 GeV HI beam with low beta insertion 
Optics studies on the transfer line and ring have been carried out to optimise the horizontal
position and angle of the septum and maximise the acceptance for LIU HI beams at 1.4 and
2 GeV. EDMS: v PS-M-ES-0002 v.1.1  

6. Septum position and angle
Future septum-bumper
Blade thickness: 11 mm
Present septum
Blade thickness: 5 mm
Present septum
dr = 64 mm
f = 10 mrad
62 cm
94 cm
1 cm
Future septum
dr = 54 mm
f = 10 mrad

7. MD1740: setup and measurements
Workflow from recorded data to final results
MD data
TIMBER: main parameters ( not all and some of them are saved for short time )
MATLAB, etc… : user scripts to save data during the MD
ROOT, MATLAB, etc.. : user has to merge the data and use scripts to analyse them
Generally data and scripts are not public
Efforts are in progress to improve the process
SWAN (Service for Web based Analysis): platform for interactive data analysis in the cloud
SWAN is becoming widely used at CERN in combination of cernbox
Interactive program environment: Jupyter
Python-based applications: so-called notebooks
Possibility to access and filter all data (TIMBER and MATLAB .m files)
Generate plots inside the environment
Create monolithic database, catalogues of analyses and encourage reproducible studies
MD1740 Postprocessing.py notebook can be found in
/afs/cern.ch/work/s/sterbini/public/2016/MD1740_SMH42

8. MD1740: setup and measurements
TOF beam
ex = 17.4 mm mrad
el = 2.75 eV s
t = 157 ns
dp/p =
I =
Knobs:
septum: position, angle
and strength
kicker45 strength
bumpers strength
Recorded signals
Beam trajectories
BLMs along the ring
BLM42 slow (yellow line)
Fast Diamond BLM42

9. MD results: TOF beam

10. MD results: TOF beam First hour: 10 mins to take reference BLMs
readings for nominal settings
Test the septum motors

11. MD results: TOF beam Second hour: Test of the diamond BLM42
using the internal dump
Optics optimization:
reduction of the bump height and
increase of kicker-septum strength

12. MD results: TOF beam Last hour: Automatized scan of SMH42
position and angle

13. MD results: TOF beam Scan of SMH42 positions and angles
BLM42 reading for nominal position (64 mm)
and angle (10 mrad) is 23 [8-bits ADC]
Lower losses for position between 54 and 61 mm
BLM42 8-bits ADC
Scan of SMH42 positions and angles
Same plot but with BLM42 reading filtered for data
below 8 [8-bits ADC]
Lower losses for position between 55 and 60 mm
and angle between 8 and 13 mrad
BLM42 8-bits ADC

14. MD results: TOF beam Previous results are confirmed by
data from OASIS channels
Diamond BLM42
Scan of SMH42 positions and angles
Fast diamond BLM42 integrated values
Lower losses for position between 54 and 60 mm
Slow BLM42
Scan of SMH42 positions and angles
Lower losses for position between 54 and 60 mm

15. MD results: SFTPRO beam
SMH42 position and
angle acquisitions
Injection optics
not optimized for
SFTPRO beam
BLMs show a slight
reduction of losses

16. MD results: SFTPRO beam
Scan of SMH42 positions and angles
BLM42 reading for nominal position (64 mm)
and angle (10 mrad) is 20 [8-bits ADC]
Lower losses for position between 54 and 61 mm
BLM42 8-bits ADC
Scan of SMH42 positions and angles
Same plot but with BLM42 reading filtered for data
below 25 [8-bits ADC]
Lower losses for position between 54 and 59 mm
and angle between 8 and 13 mrad
BLM42 8-bits ADC
Similar results for AD and LHC beams

17. Conclusions MD results were very positive
Septum position (around 56 mm instead of 64 mm) reduces the losses of a factor 3 for HI beams with the drawback of pushing the septum strength too close to its maximum value, i.e. reduced lifetime
A lower position of the septum is also compatible with LIU requirements for 1.4 and 2 GeV beams