Predicting PEP-II Accelerator induced backgrounds with LPTURTLE

Predicting PEP-II Accelerator induced backgrounds with

LPTURTLE

TPPP023

Roger Barlow – Manchester and Cockcroft

Witold Kozanecki – CEA/DSM/DAPNIAPatrick Roudeau & Achille Stocchi –

LALTed Fieguth – SLAC

Stephanie Majewski - Stanford

Collimators

HER LER

PEP-II Regions Map

LER

Collimator Studies

Gray dots hit the ring harmlessly.

Black dots hit the ring near the IP

Gap in the middle survive

Tightening the far collimators

and moving the upstream

collimator downstream will minimize background

The ones that hurt

Radiative Bhabhas

MC from Burkhardt and Kleiss

87.57

6.56

5.5

4

3.532.5

21.51

0.5

4.55

HER Radiative Bhabhas

32.5

2 1.51

0.5

LER Radiative Bhabhas

-7.5 -5 -2.5 0 2.5 5 7.5

0

10

20

30

-10

-20

-30

m

cm

M. SullivanFeb. 8, 2004API88k3_R5_RADBHA_TOT_7_5M

3.1 G

eV

3.1 G

eV

9 GeV

9 GeV

PEP-II Radiative Bhabhas

Dose is all

in horiz plane

Beam Gas: Coulomb and Bremsstrahlung

Need for importance sampling in the simulation to avoid poles and inefficiency

Regions in z and

Where do they come from? Regions

Z and azimuth for HER and LER