B. Heltsley Ecal DPG Sim Status - 11 Feb 2010 1 Ecal Simulation
Status Ecal Shape Status & validation SLHC Ecal simulation
needs Ecal noise improvement plans 1 st /2 nd Generation APD
Simulation Brian Heltsley Ecal DPG 11 Feb 2010 Slide 2 EE Shape
Validation Historical summary (previously reported) Structural
changes to Ecal code relating to having separate EB & EE shapes
was ready last fall. First stage went into 3_4_0 which had separate
EE shape classes but kept the EB shape for the EE object, so no
real change in behavior. (B. Heltsley) C. Neu extracted EE pulse
shape from EE TB data & this was checked into CMSSW into the EE
class but not published K. Theofilatos extracted the necessary EE
weights from the above that are used in the reconstruction Weights
needed to put into the DB (help from J. Fay, F. Cavallari, )
Coordination along the way from F. Ferri, M. Hildreth, T.
Tabarelli, BUT Validation was plagued by puzzles which it was
thought better to solve than have any doubt Finally B. Gobbo
stepped up to the plate to provide the definitive validation
assurances. B. Heltsley Ecal DPG Sim Status - 11 Feb 2010 2 Slide 3
EE Shape validation Grazie, Benigno! B. Heltsley Ecal DPG Sim
Status - 11 Feb 2010 3 New shape (black) Is different!
RecHit/SimHit is the same! All changes to go into CMSSW_3_6_0_pre1.
Thanks to the Very very many people who contributed to this
completion. Slide 4 SLHC Ecal Simulation What is required of Ecal
Simulation to plan for the SLHC? Chris Neu (U.Va.) organized an
initial meeting of some interested parties C. Neu, C. Jessop, B.
Cox, S. Banerjee, R. Ruchti, B. Heltsley Just getting started Time
slot is tentatively Fridays 14:00 Eastern time, 20:00 CERN time, as
convenient for these participants & open Chris should give an
update in a few weeks B. Heltsley Ecal DPG Sim Status - 11 Feb 2010
4 Slide 5 Ecal Noise Plans Ecal noise simulation to be improved T.
Tabarelli de Fatis has outlined a plan for us in the simulation
group to follow Resurrect the (time-dimension) correlation matrix
code for the barrel Make structural changes to have a separate
correlation matrix for the endcap Adjust other parameters as
necessary so as to match reality as closely as possible; will
require iterative procedure Simulate noisy channels in inner EE C.
Neu & myself to implement, preferably for CMSSW_3_6_0_pre1 or
pre2 Details to follow B. Heltsley Ecal DPG Sim Status - 11 Feb
2010 5 Slide 6 Other matters L1 Emulator Update How to make a L1
spike veto? J. Jackson (Bristol) has implemeted some necessary
tools in CMSSW_3_5_0_pre? Studying different algorithms &
thresholds Work in progress ES gain: preshower gain needs to be
adjusted in the cfg (C.M. Kuo) B. Heltsley Ecal DPG Sim Status - 11
Feb 2010 6 Slide 7 7 5x5 mm 2 APDs initially present in simulation
as shown APD thickness magnified greatly for visualization purposes
actual thickness in simulation is 5 m. Material is Si. Inactive by
default, but Sunanda Banerjee has a private tarball of changes to
make these volumes active and generate SimHits. See Jim Bransons
talk following this one. Slide 8 But is a simple APD good enough?
Perhaps Perhaps not (Jim Branson et al.) If Ecal spikes are related
to APDs, perhaps more detail would help us understand what is
happening Details of APD response and local materials can
potentially make a difference e.g. Protective epoxy coating has
lots of oxygen which has larger neutron cross section. Wont know
unless we try it, so B. Heltsley Ecal DPG Sim Status - 11 Feb 2010
8 Slide 9 The Physical APD B. Heltsley Ecal DPG Sim Status - 11 Feb
2010 9 Top 100 has ~20% Boron Slide 10 Notes on real APD Two active
layers Different thicknesses & gains Epoxy coating on front
Bulk inactive Si on back & sides Top 100 m formed by Boron
implantation & diffusion at ~20% concentration 2 stable
isotopes of Boron (Z=5) 11 5 B 5 has 80% abundance, J P =3/2 10 5 B
5 has 20% abundance, J P =3 + 10 B + n 7 Li (0.84 MeV) + (1.47 MeV)
has =3840 barns for thermal neutrons. drops with increasing neutron
energy as 1/velocity Can GEANT simulate any of this? Sunanda
Banerjee investigating B. Heltsley Ecal DPG Sim Status - 11 Feb
2010 10 The Real Thing Technical information courtesy of Yuri
Musienko & Jim Branson Slide 11 Tentative 2 nd Generation APD
B. Heltsley Ecal DPG Sim Status - 11 Feb 2010 11 Picture from
iguana 3_5_0_pre5 Thicknesses magnified for visualization purposes
Plastic Capsule 4mm Ceramic case 1.6mm Bulk Silicon 400 Epoxy 200
Non-depeleted Si 0.1 Sensitive 5 Si Less sensitive 45 Si Crystal
APD Geometry Implementation by B. Heltsley Slide 12 Other views B.
Heltsley Ecal DPG Sim Status - 11 Feb 2010 12 Crystal Side View,
magnified thicknesses Crystal Front View, Correct thicknesses Slide
13 APD Names & materials Numbered from 01-17 # different barrel
crystal shapes Even though identical, must have different names
because they reside in differently-named mother volumes EAPD_nn:
sensitive volume (higher gain): Si (add Boron?) EATJ_nn: sensitive
volume (lower gain): Si (After The Junction) EGLU_nn: Epoxy: C
(54%), H (13%), O(33%) EBSi_nn: Bulk Si ECER_nn: Ceramic (?)
package: Si(30%), O(48%), K(6%) Using Borosilicate_Glass until
actual composition is known EAND_nn: Non-Depleted layer: Si (add
Boron?) ECAP_nn: PEEK Capsule: C (54%), H (13%), O(33%) B. Heltsley
Ecal DPG Sim Status - 11 Feb 2010 13 from
CMSCommonData/data/materials.xml Slide 14 Modified files
Geometry/EcalCommonData/ data/ebalgo.xml
interface/DDEcalBarrelAlgo.h src/DDEcalBarrelAlgo.cc
src/EcalBarrelNumberingScheme.cc These 4 files are in
/afs/cern.ch/user/h/heltsley/public/apdbkh Builds in
CMSSW_3_5_0_pre5 Slight mods will be needed for pre6 due to DDD
changes by Michael Case Feedback appreciated Sunanda has adapted
his code to return depth=1 & depth=2 for the 2 APD layers
(crystal has depth=0) See next talk for status of testing B.
Heltsley Ecal DPG Sim Status - 11 Feb 2010 14
