1. PLACET collimator studies
The University of
Manchester
PLACET collimator studies
for ESA and ILC BDS.
Adina Toader
School of Physics and Astronomy, University of Manchester
& Cockcroft Institute, Daresbury Laboratory

2. Collaborators Roger Barlow University of Manchester Roger Jones
Adriana Bungau
Deepa Angal-Kalinin Daresbury Laboratory, ASTEC
Frank Jackson
Jonny Smith Lancaster University
Daniel Schulte CERN Geneva
Andrea Latina
Giovanni Rumolo

3. Introduction
For ILC BDS spoiler wakefields have only been estimated analytically.
- Lack of beam tracking simulations with wakefields effects.
PLACET is useful tool for simulating rectangular aperture spoilers.
- It includes both geometric and resistive effects.
PLACET has demonstrated usefulness in studying CLIC BDS wakefield effects.
Use PLACET to reproduce ESA measured kicks Benchmarking exercise.
Use PLACET to estimate ILC BDS luminosity reduction and emittance dilution due to the spoilers wakefields.

4. ESA Collimators a Collimator Side view Beam view α = 324mrad r = 2 mm
h=38 mm
38 mm
α = 324mrad
r = 2 mm
r = 1.4 mm
α = 166mrad
r = 1.4 mm 1 a
r=1/2 gap 2 3
L=1000 mm 6

5. Kick Factors for ESA Collimators
Bunch size, σz =0.5 mm
Coll Kick Factors (µrad/mm) - Linear Fit
Geo Res Total Analytical Measured*
Coll α(mrad) r (mm) LT (mm) LF(mm) σ(Ω-1m-1) material
e OFE Cu
e OFE Cu
e OFE Cu
e OFE Cu
e Ti6Al4V
*PAC07 S. Molloy et al.”Measurements of the transverse wakefields due to varying collimator
characteristics”

6. Kick Factors for ESA Collimators
Bunch size, σz =0.5 mm
Coll Kick Factors (V/pC/mm)
PLACET Analytic Prediction * Measured*
±0.1 (1.0)
±0.1 (1.3)
±0.1 (1.5)
±0.1 (7.9)
±0.1 (0.9)
Coll α(mrad) r (mm) LT (mm) LF(mm) σ(Ω-1m-1) material
e OFE Cu
e OFE Cu
e OFE Cu
e OFE Cu
*PAC07 S. Molloy et al.”Measurements of the transverse wakefields due to varying collimator
characteristics”

7. Kick Factors for ESA Collimators
Bunch size, σz =0.35 mm
Coll Kick Factors* (µrad/mm)
Geo Res Total
Bunch size, σz =0.75 mm
Coll Kick Factors* (µrad/mm)
Geo Res Total
Bunch size, σz =0.5 mm
Coll Kick Factors* (µrad/mm)
Geo Res Total
Bunch size, σz =1.5 mm
Coll Kick Factors* (µrad/mm)
Geo Res Total
*Linear Fit

8. PLACET tracking results for ILC BDS
Luminosity reduction and emittance dilution due to the collimator wakefields. The beam offset is applied at the beginning of BDS.

9. ILC BDS Collimators No Name Type Z (m) Aperture 1 CEBSY1 Ecollimator
37.26 ~ 2
CEBSY2
56.06 3
CEBSY3
75.86 4
CEBSYE
Rcollimator
431.41 5
SP1
x99y99 6
AB2
x4y4 7
SP2
x1.8y1.0 8
PC1
x6y6 9
AB3 10
SP3 11
PC2 12
PC3 13
AB4 14
SP4
x1.4y1.0 15
PC4 16
PC5 17
AB5 No
Name
Type
Z (m)
Aperture 18
SP5
Rcollimator
x99y99 19
PC6
Ecollimator
x6y6 20
PDUMP
x4y4 21
PC7
x120y10 22
SPEX
x2.0y1.6 23
PC8 24
PC9 25
PC10 26
ABE 27
PC11 28
AB10
x14y14 29
AB9
x20y9 30
AB7
x8.8y3.2 31
MSK1
x15.6y8.0 32
MSKCRAB
x21y21 33
MSK2
x14.8y9

10. Kick Factors for ILC BDS Collimators
Bunch size, σz =0.3 mm
Coll Kick Factors* (µrad/mm)
Geo Res Total SP SP
SPEX
Coll α(mrad) r (mm) LT (mm) LF(mm) σ(Ω-1m-1) material
SP e OFE Cu
SP e OFE Cu
SPEX e OFE Cu