Section meeting 22/08/06

Energy deposition study on D0 1

FLUKA Energy deposition study :

Early separation scheme with Dipole D0

First ResultsChristine HOA (AT-MAS-MA), Guido STERBINI (AT-MAS-MA),

Section meeting 22/08/06

Energy deposition study on D0 2

Outline

LHC Upgrade configuration with D0 FLUKA energy deposition calculations

Monte Carlo code Modeling parameters D0 results for energy deposition

Investigations: P-P collisions Next steps Conclusions

Section meeting 22/08/06

Energy deposition study on D0 3

LHC Upgrade configuration with D0 Early scheme D0 dipole

Q1 Q2 Q3Q2Q3

IP

D0D0

Q1

Upgrade luminosity: 10 35cm-2 s-1

Total power: 18 kWQuestion: Energy deposition in the dipole?… in the IR quads?

Section meeting 22/08/06

Energy deposition study on D0 4

FLUKA: Monte Carlo code

Multi-particle transport code CERN/INFN development

A. Ferrari, P.R Sala, A. Fassò, J.Ranft

Fluka team with technical support at CERN

Version 2006, not yet released Including DPMJET

Event Generator

for the p-p collisions

DPMJET

FLUKAParticles trackingInteractions/ TransportEnergy deposition

GEOMETRY Magnetic field

Post-treatmentsFlukaplot.r, Simplegeo, fluka Gui, MATLAB, Mathematica

Source particles

Simplegeo V.2,DTUJET, DPMJET ROXIE, …

Section meeting 22/08/06

Energy deposition study on D0 5

FLUKA: Modeling parameters

Section meeting 22/08/06

Energy deposition study on D0 6

FLUKA: Modeling parameters

Beam parameters

p-p collision DPMJET event generator

Crossing angle 0

x (m) 11.81E-6

y (m) 11.81E-6

z (m) 7.55E-2

L, Luminosity 1035

A, Cross section (mbarn) 80

Section meeting 22/08/06

Energy deposition study on D0 7

FLUKA: Modeling parameters

Meshing Cartesian mesh: 0.2*0.2*2 cm Physical meaning with

respect to quench limitrelated to minimum cable dimension (width of 1-2 mm)

(discussion with D. Tommasini)

Computing parameters Nb of particles for good

statistics: 3*1000 particles (CPU time 16 hours)

Cut-off parameters

Number of primary particles

3000

CPU time 16 h

Cut off energy for e-/+e-

<30 keV in the dipole and beam pipe<2 MeV in the Air cylinder region

Cut off energy for photons < 3 keV in the dipole and beam pipe< 200keV in the Air cylinder region

Cut off energy for Hadrons/ Muons

<100 keV

Cut off for high energy neutrons

< 19.6 Mev

Cut off for low energy neutrons

thermal energies

Section meeting 22/08/06

Energy deposition study on D0 8

FLUKA: D0 results Without magnetic field

1st slide of the dipoleZ=[0,2] cm

Section meeting 22/08/06

Energy deposition study on D0 9

FLUKA: D0 results Without magnetic field

36 mW/cm3

12 mW/cm3

Section meeting 22/08/06

Energy deposition study on D0 10

FLUKA: D0 results

With a constant magnetic field of 6 T

Section meeting 22/08/06

Energy deposition study on D0 11

FLUKA: D0 results

With a constant magnetic field of 6 T

Section meeting 22/08/06

Energy deposition study on D0 12

FLUKA: D0 results

Comparing results: deposited power in D0

Total heat deposition

(W)for L=1035 and A=80

mbarn

Averagedheat

depositiondensity

(mW/cm3)

Maximun heat depositiondensity(mW/cm3)

Quench limit

IR in quadsNb Ti

(mW/cm3)

Quench limit

Nb3Sn quads

(mW/cm3)

Without magnetic field

33.4 8.3 48.3 12[Mokhov]

36[Mokhov]

With magnetic field of 6 T

34.3 8.6 49.7 12[Mokhov]

36[Mokhov]

[Mokhov]: “Beam induce energy deposition studies in IR Magnets”, April 2006, WAMDO workshop

Section meeting 22/08/06

Energy deposition study on D0 13

FLUKA: D0 results

Summary 34 W deposited power in the dipole no influence of the magnetic field

Opening questions Why such a small value?

Investigation on the p-p collision:

Spatial distribution and energy range

Section meeting 22/08/06

Energy deposition study on D0 14

P-P collisions analyses

Aim: Distribution of secondaries w.r.t of energy range and space

Y

p-p collision at 14 TevUpgrade Luminosity 1035 cm-2.s -1 18kW

Polar distribution: from 0 to 180

Sphere: 180 ring regions

Z

X

Section meeting 22/08/06

Energy deposition study on D0 15

P-P collisions analyses

Far field region of the interaction at R>3.5m

Section meeting 22/08/06

Energy deposition study on D0 16

P-P collisions analyses Spatial distribution (no crossing angle)

IP

D0 dipoleIR=3.5 cmOR=5 cm

=0.75=0.35

1 m3.5 m

Section meeting 22/08/06

Energy deposition study on D0 17

P-P collisions analyses

Scaling law for aperture radius

Section meeting 22/08/06

Energy deposition study on D0 18

P-P collisions analyses

Power spectrum in D0 dipole

1 Gev-100 Gev : narrow power spectrum

62% Charged particles38% Neutral particles30% Photons

Section meeting 22/08/06

Energy deposition study on D0 19

P-P collisions analyses

Power spectrum in D0 dipole

Photon total energy in D0: 44 Wmost of this energy is deposited in D0

Section meeting 22/08/06

Energy deposition study on D0 20

Next steps

Origins of the energy deposition More details on charged particles?

To take into account Crossing angle : small effects expected?

Magnetic field of the Solenoid: small effects expected?

Section meeting 22/08/06

Energy deposition study on D0 21

Conclusions

FLUKA results: 34 W of power deposition

Good surprise! Understanding of this result

Z> 3.5 m :far field region of the p-p interactions High energetic particles channeled in the beam pipe Impinging energy in the dipole at 3.5 m: 144 W

Solutions to decrease the energy deposition: Increase the aperture of D0 front absorber