H8 FLUKA simulations

Marco Garattini

INFN - Roma “La Sapienza”

“H8 Analysis for UA9 Experiment”

12 March 2013 - CERN

Outline• H8 FLUKA simulations: - Goal of the simulations

- Input: Geometry, beam, scoring regions etc…

- Output: particles scored, informations scored

• Scintillator scan score• π ± to understand Nuclear Interactions • Air VS Vacuum• Polystyrene Trigger simulations• Conclusions and future prospects

12 March 2013 - CERN

Goals of the H8 FLUKA simulations

• Understand better the Nuclear Interactions of the beam with the Crystals

• Test the detectors perturbations on the beam

• Test the enviromental conditions: Air VS Vacuum

• Find the best position and material for triggers,

detectors and instrumentations

My H8 Geometry for FLUKA

Crystal STF2Silicon

Δx = 1 mm Δy = 50 mmΔz = 2 mm

Two Si sensors overlap

S = 38 x 38 mm2

Δz = 640 µm

M. Pesaresi,1 W. Ferguson, J. Fulcher, G. Hall, M. Raymond, M. Ryan and O. Zorba

Input Beam

• Protons• N = 106

• E = 400 GeV• Flat, rectangular: 1 mm x 1mm• Divergence: 8 µrad• Centered on the Telescopes and the

Crystal

Scoring Region

Scintillator Scan from SiTel1 to SiTel5

• Valume : (X = 10 cm) x (Y = 10 cm) x (Z = 2120 cm)

• Distance from the beam axis: 10 cm

• Score binning: every 10 cm

• Medium: Air or Vacuum

Scored Particles

Fluence along Z direction: Φ = dN/dA┴

• Protons• Electron ±

• Pions ± (the result of Nuclear Interactions of the protons with Si)• Pions 0• Muons ±• Neutrons• Photons

• Fluence values are per cm2 and normalized to the number of initial particles:

- N = 106 p- A = (10 x 10) = 100 cm2

π± Fluence Plots

Air With Crystal Air No Crystal

SiTel-1-2-3-4-5 Crystal STF2 (no channeling)

z

π ±

Φ

SiTel-1: z = 0 cm SiTel-3: z = 1100 cm SiTel-2: z = 1029 cm SiTel-4: z = 1122 cmSTF72: z = 1058 cm SiTel-5: z = 2118 cm

4.0 x 103

π ±

z

Φ

4.5 x 103

π± Fluence Plots

Vaccum With Crystal Vacuum No Crystal

SiTel-1-2-3-4-5 Crystal STF2Φ

z

Φ

z

SiTel-1: z = 0 cm SiTel-3: z = 1100 cm SiTel-2: z = 1029 cm SiTel-4: z = 1122 cmSTF72: z = 1058 cm SiTel-5: z = 2118 cm

π ± π ±

1.8 x 103

1 x 103

Best Scintillator Z position To understand which is the best Z position for the Scintillator,

I have computed the ratio:

R = Φ(WithCry)/ Φ (NoCry)Obtaining the position of the high ratio of π ± fluence in the two cases.

z

Φ(With)/Φ(No)

The best position for the Scintillator:

- Z=1100 cm from the SiTel-1

- The same Z of the SiTel-3

- X =10 cm from the beam axis

Polystyrene Trigger UpstreamΦ of π ±

ΔZ = 1 cm ΔZ = 5 mm

ΔZ = 1 mm

- Polystyrene - ρ = 1.06 g/cm3

- A = (5 x 5) cm2

- Z = 0- 9 cm before SiTel-1

7.5 x 102

5 x 102

2.5 x 102

Conclutions• The Crystal increases the numbers of π ±, as result

of the Nuclear Interactions• The best position for the Scintillator is:

X= 10 cm with respect to the beam axis

Z = 1100 cm from the SITel-1• The “Air effects” are evident • The Upstream Polystyrene Trigger produces

perturbations on the beam:

- thickness of 5 mm may be ok ?

Future prospects

• Simulations with Lead Ions beam: - work in progress…

• Integration of additional components on the H8 line: triggers, different crystals, detectors etc..

• Implementation of additional geometry details

12 March 2013 - CERN

THANK YOU

SPARE