Pile up

Speaker : All (Wei Xie convenor)


Talk time : 13:30, Duration : 00:20

Progress on (d)efficiency

Speaker : Willie


Talk time : 13:10, Duration : 00:20

The slides are at

http://www.star.bnl.gov/protected/spin/wleight/TUP/080307/

General updates on proposal, review etc

Speaker : All


Talk time : 13:00, Duration : 00:10

Software Status

Speaker : Jonathan and Vi Nham


Talk time : 00:40, Duration : 00:10

SSH Key Management

Under:

Overview 

An SSH public key management system has been developed for STAR (see

Tools

Under:

This is to serve as a repository of information about various STAR tools used in experimental operations.

Diffusion and Delta Electrons in the FGT Simulator

In order to get the most realistic performance possible out of the FGT Slow Simulator, all important physical effects have to be incorporated.

Shall the US contingent plan on making a trip to Nantes to discuss the proposal, an MOU, and/or system tests?

Speaker : Jim


Talk time : 00:13, Duration : 00:01

When to send the last Shipping Crate

Speaker : Jim


Talk time : 00:11, Duration : 00:07

Helen Caines to chair a small committee to look at to re-install the SSD.

Speaker : Jim


Talk time : 00:05, Duration : 00:05

Proposal

Speaker : Howard


Talk time : 00:00, Duration : 00:05

New embedding framework status

Speaker : Andrew Rose, Lee Barnby et al. ( LBNL, BHAM,... )


Talk time : 12:45, Duration : 00:10

Overview of farm status

Speaker : Jerome Lauret ( BNL )


Talk time : 12:55, Duration : 00:05

Mainly a rundown of issues described in http://www.star.bnl.gov/HyperNews-star/pr

Production estimates

Speaker : Lidia Didenko ( BNL )


Talk time : 12:30, Duration : 00:15

 Trigger      #events    CPU/evt (3.0 GHz)    Timescale for production

Production plans

Speaker : Jerome Lauret, James Dunlop ( BNL )


Talk time : 12:00, Duration : 00:15

Calibration, dE/dx overview for Run VII

Speaker : Yuri Fisyak, Gene V. Buren ( BNL )


Talk time : 12:15, Duration : 00:15

Modeling dead time behavior for the new SSD readout architecture

Speaker : Micheal


Talk time : 00:20, Duration : 00:20

I report on a modeling calculation for the dead time behavior of the new SSD readout system using 1 and multiple buffers at the
input of the RDO.

Material Balance Histograms

Under:

.

Description of the slow simulator procedures for the BEMC

BSMD

The SMDs can be simulated in one of two modes.  In a rewrite of the slow simulator I call them kTestMode and kSimpleMode.  kTestMode doesn't do anything interesting, so let's focus on kSimpleMode.  Here are the steps to generate an ADC:

  1. ADC = energy deposit * sampling fraction(eta) / calib
  2. ADC += mRandom.Gaus(pedMean, pedRMS)
  3. ADC *= mRandom.Gaus(1.0 + calibOffset, calibSpread)
  4. force ADC between 0 and maxADC

The energy is then calculated from this ADC is the usual way:  energy = (ADC - pedMean) * calib.  Remember the BEMC calibration coefficients are stored as GeV/ADC.

BTOW - BPRS

The simulators for these two detectors have some additional modes (kPrimaryOnlyMode, kPrimarySecondaryFastMode, kPrimarySecondaryFullMode).  Here's the setup for the kPrimaryMode:

  1. photoElectrons = energy deposit * (MIP photo electrons / MIP energy deposit)
  2. smear using Poisson distribution
  3. ADC = photoElectrons * sampling fraction(eta) * (MIP energy deposit / MIP photo electrons) / calib
  4. follow steps 2-4 of simple simulator to add pedestals, smear calibration, and check for valid range

The other two modes also take the secondary photostatistics from the PMT amplification into account.  I'll focus on the full mode, as it's slightly easier to understand:

  1. build a set of secondary electron conversion coefficients (1 / dynode) using the relative voltage distribution among the dynodes and an approximate value for the total PMT amplification.
  2. Loop through dynodes and at each step
    1. nElectrons = mRandom.PoissonD( mSecondaryCoeff[i] * nElectrons + mDynodeNoise );
  3. ADC =  nElectrons * mTotalDynodeGain *sampling fraction(eta) * (MIP energy deposit / MIP photo electrons) / calib
  4. follow steps 2-4 of simple simulator above

The mTotalDynodeGain in step 3 is the inverse of the product of the secondary electron conversion coefficients.

Tunable Parameters for BEMC slow simulator

sampling fraction -- each sampling fraction is a 2nd order polynomial in eta.  Here are the values currently being used:
BTOW = 14.69 - 0.1022*eta + 0.7484 * eta^2
BPRS = same as BTOW (pams/emc/inc/samplefrac_def.h includes different number)
BSMDE = 118500.0 - 32920.0*eta + 31130.0*eta^2
BSMDP = 126000.0 - 13950.0*eta + 19710.0*eta^2

Here are the numbers for BPRS from pams/emc/inc/samplefrac_def.h:
#define P0BPRS  559.7
#define P1BPRS -109.9
#define P2BPRS -97.81

max ADC value -- BTOW(3500), BPRS(220), SMDs(900)

Calibration offset (0.0) -- shifts all calibration coefficients during generation of ADCs.

Calibration spread (0.0) -- smears ADCs with a Gaussian.  A spread of 0.15 for the BTOW has been used in recent analyses.

The following params are only used by the slow simulator for the BTOW and BPRS:

MIP photo electrons -- BTOW(63.0), BPRS(6.0)
MIP energy deposit -- BTOW(19.8 MeV), BPRS(2 MeV)

The ratio of these two is used to translate the energy deposit from GEANT into a number of photoElectrons which is then fed into the StPmtSignal simulator.

approximate PMT amplification (1.5e+6).  Does NOT affect overall gain, which is a separate input parameter.  Basically only determines some widths in the PMT simulator.

relative dynode voltage distribution {2.,2.,1.,1.,1.,1.,1.,1., 2., 3., 4.}

cathode noise (0.0) A probability for a thermal electron (or the average number of thermal electrons per pulse) to spontaneously emerge from the photocathode within the ADC gate.

dynode noise (0.0) A probability for a thermal electron (or the average number of thermal electrons per pulse) to spontaneously emerge from a dynode within the ADC gate. This probability is assumed to be the same for all dynodes.

For these 2 detectors one can choose between simple, fast, and full simulators.  The only difference between full and fast is that at high numbers of photo electrons the PMT simulator switches to Gaussians instead of Poisson distributions.  We've been inadvertently running the fast simulator for some time now due to a flip in indices in the simulator code, but according to V.Rykov's documentation the two are in good agreement.  The simple simulator is the one used by the SMDs; no accounting for secondary photostatistics is done, so the ADC value is basically (energy deposited * sampling fraction * gain), plus pedestal noise and calibration smearing.