Ecloud Heat Load simulations

for the LHC arcs

Humberto Maury Cuna

E-cloud Simulation Meeting

June 16th, 2011

Simulation parameters for 50 nsBunch spacing

Bunch intensity

SEY Reflectivity

Fill pattern

Energy

50 ns 1.2 x 1011 p/b

1.6-

2.4

0.2-

0.91 3.5 TeV*

36bunches

36 bunches200n

s(1) X 3

* We used a primary photoelectron emission yield =0.0001233

nistep = 2500

Bunch length

sx, sy Magnetic field

Pressure Energy

9 cm 0.3 mm 4.195 T --- 3.5 TeV

1.1 µs

Fill 1704 (13/4/2011 – 12:16 to 16:47)

Multipacting

3.5 TeV

Interspace: Times the space charge field is recalculated. (10 30, 100).

Nbstep: Number of intermediate steps per bunch passage . (150 450).

Nistep: Number of intermediate steps per inter bunch drift. (2500 5000).

Npepb: Number of macroparticles/bunch. (500 2000).

Simulation parameters for 50 ns – Drift

Bunch spacing

Bunch intensity

SEY Reflectivity

Fill pattern

Energy

50 ns 1.15 x 1011 p/b

1.7-

2.30.3 1 3.5 TeV*

36bunches

36 bunches200n

s(1)

* We used a primary photoelectron emission yield =0.0001233

nistep = 2500

Bunch length

sx, sy Magnetic field

Radius(mm)

Energy

9 cm 0.3 mm 4.195 T 15 - 50 3.5 TeV

20 30 40 50 60 701.01.11.21.31.41.51.61.71.81.92.02.12.22.32.4

Seco

ndar

y em

issi

on y

ield

(M

ax)

Radius (mm)

Multipacting Threshold vs. Chamber Radius

Simulations with and without sawtooth pattern

3.5 TeV

Simulation parameters sawtooth pattern simulations

Bunch spacing

Bunch intensity

SEY Reflectivity

Primary photoelectron emission yield

Energy

25 ns 1.15 x 1011 p/b

1.2-

1.50.5

0.0001233

0.001233

3.5 TeV

7 TeV

72bunches 200n

s

nistep = 2500

Bunch length

sx, sy Magnetic field

Primary photoelectron emission yield (w/o pattern)

Energy

9 cm

7.55 cm

0.3 mm4.195 T

8.39 T

0.0002466

0.002466

3.5 TeV

7 TeV72bunche

s

Simulations with and without sawtooth pattern

7 TeV

Thank you for your attention