status of multi-turn tracking of protons from ir debris · s. redaelli, 3rd colusm, 23-02-2012...

Stefano Redaelli, BE-ABPAcknowledgements: R. Bruce, T. Weiler

Status of multi-turn tracking of protons from IR debris

3rd LHC Collimation Upgrade Specification MeetingCERN, Geneva

23rd February 2012

S. Redaelli, 3rd ColUSM, 23-02-2012

Outline

2

ScopeMulti-turn trackingExamplesLoss mapsOutlook


Scope

3

We need tools to track the product of collisions around the ring! - Multi-turn tracking! - Precise treatment of large off-momentum errors! - Model the interaction with the collimators

Natural choice: SixTrack version for Collimation studies! - For the moment, different simulation setup to study the ! interaction of primary protons on the collimators of IR7/3

Need to setup tracking using external input distributions from IP1/2/5! - Done in the past (T. Weiler, F. Roncarolo, et al.) within ! different scopes

Today: only discuss proton simulations


Multi-turn tracking from IP1

4

Input distributions in IP1x xʼ

yʼy

(x,xʼ) (y,yʼ)

Example: start tracking in IP1, 3.5 TeV (2011 config)

Initial distributions generated off-lineCrossing and separation: ! computed by SixTrackThen, standard tracking with collimators

Nominal bunch, on-momentum, 640 trajectoriesShown: Vertical (crossing) plane

Nominal aperture

Layout elements


Example: tracking results

5

Trajectories in IP5

Developed tools to check distributions at various elements around the ring→ will use them for particle distributions at the cryo-collimator locations

x

(x,xʼ)

y

xʼ

(y,yʼ)

yʼ

IP5 transverse distributions


Tracking of off-momentum particles

6

Case study: flat distribution of δp/p, zero initial betatron amplitude at IP1

δp/p = -5%

δp/p = 0


Acceptance for Aβ=0

7


3.4 3.5 3.6 3.7 3.8 3.9 40

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

Hor

izon

tal m

omen

tum

cut

[ p/

p ]

Longitudinal coordinate [ km ]

p/p=0.012

p/p=0.055

IP2

Analytical models

8

�δp

p

�

cut

=A(s)/2−∆CO(s)

Dx(s)Approximated linear

model

13.3 13.4 13.5 13.6 13.7 13.8 13.9 140

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

Hor

izon

tal m

omen

tum

cut

[ p/

p ]


IP5

δp/p = -0.83%

δp/p = -1.8%


Following the particles around the ring...

9


More realistic IP distributions

10

Real betatron distributions for different δp/p!Color coding:# 0.4 %# 0.6 %# 0.7 %# 1.0 %# 1.2 %

Momentum acceptance can be re-computed with the betatronic transverse distributions


Tracking of off-momentum bunches

11

Interactions with primary collimators of IP3


Example of loss maps from IR1

12

0 0.1 0.2 0.3 0.4 0.5 0.60

20

40

60

80

100

120

140

160

180

200

N


Example: zero Aβ with δp/p cut at 5%

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.510-6

10-5

10-4

Longitudinal position [ km ]

Beam

loss

es [

Gy/

s ]

Measurements in physics (fill 2242)

2.9 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.810-7

10-6

10-5

10-4

10-3

Longitudinal position [ km ]

Beam

loss

es [

Gy/

s ]

IP2

MQXʼs

MB10

IP2: Ion operation


A look at other IPs

13

δp/p = -5%

δp/p = 0

IR2 tracking


Outlook

14

Presented the status of tracking tools for single- and multi-turn losses of IR products! - SixTrack with collimation routines were prepared to study what leaks ! out of the IPSTools are ready to start detailed simulations!! - Tracking under control.! - Can produce loss maps for present machine layout! ! - Still to improve and fully debug preliminary setup to start in different IPs! - Comparison with analytical models to check dynamics of ! off-momentum particlesNeed realistic particle distributions from the p-p collisions!

! ! - See previous talk by Francesco What comes next:! - Simulations with real distributions from FLUKA! - Comparison with 2011 data at 3.5 TeV! - Study dependence on beam and machine configurations (Xing) ! to define a solid layout for DS collimators

status of multi-turn tracking of protons from ir debris · s. redaelli, 3rd colusm, 23-02-2012...

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