forward hadron upgrade in the next run scj for the llnl crew
TRANSCRIPT
Forward Hadron Upgrade in the Next Run
SCJ
for the LLNL crew
The Physics PitchThe Physics Pitch
PHENIX AA centrality derived from ZDC/BBC+glauber Hard processes proportional to Nbinary
Soft processes proportional to Npar pA centrality same basic idea
Npar –1 = Nbinary= Use grey/black tracks Normalization to pp differs by factor of 2
Best example of physics from pA centrality is E910 PRL 85 (2000) 4868 PRC 60 (1999) 024902
Best physics case for PHENIX may be J/ Others: high pt, Cronin effect, strangeness, etc.
NbinaryNpart
Need to measure grey/black nucleons for centrality measurement
ZDC is Insufficient
Simple model results from last time Centrality () is most
directly related to the number of grey nucleons
Black neutron relation is smeared
Et and multiplicity provide very little leverage
ZDC measures black nucleons (by design)
Grey neutrons significantly covered by rings
Black and grey protons separated and measurable
Grey protons look most promising
Difficulties Large multiple scattering
between bending magnet and upgrade in DX-D0 interconnect wall
Change of DX-D0 interconnect wall? Not this year.
Measure total energy, not individual protons?
Simulations ongoing Phototubes are above ZDC.
Geometry of grey neutron measurement is difficult
Geometry for protons is easy
ZDC
FHC
Scroungacal December meeting: suggestion to scrounge a
calorimeter for quick measurement next year The problem: if we run dA next year when is the earliest time we
could do it again? 2 or 3 years? Can we really wait that long till we have a serious dA centrality
comparison run? Could be a big payoff to put something in quick.
Results: Large Fe calorimeter at FNAL (S. Pordes)
Traveled to FNAL last month to save it from the scrap heap. Small Cu calorimeter at BNL (C. Woody)
Looking into it this week E864 Pb calorimeter (J. Sandweiss)
Still looking into it …
E609/683 – Jets at FNAL fixed target (400 GeV protons)
Segmented Pb-Sci and Fe-Sci calorimeter Segmentation radiation
depth (6-8 I) and LSci/LFe dependent on position relative to beam
Construction started in 1982 (IEEE NS-29, `82)
Data collection ended 10 years later
EE
EELECTRONS
EE
EHADRONS
%35
%70
Scheduled for the scrap heap
Unused for 10 years. Stephen Pordes (Deputy Head
of the Particle Physics Division) tried to quickly scrap it in early December.
Mike Heffner and SCJ road trip to FNAL in January.
Calorimeter sitting outside for a few weeks, but most components look ok.
Finer segmentation modules are shielded from the elements.
Worries re: FNAL calorimeter Scintillator (Rohaglass 2003) a little
yellow E683 experts [Don Lincoln (FNAL) and
Marj Corcoran (Rice)] assure me it’s ok.
Glue joints btw wavelength shifter bars and light guides
Phototubes EMI S/N 9837B
10 stage Bi-alkali photocathode 5cm envelope
Photocathode deposited on a mica substrate slightly removed from the end window to eliminate Cerenkov light from showering particles. (Cerenkov Light trapped by total internal reflection – cannot reach cathode)
All of these problems seem surmountable – luckily we only need a fraction of the modules to be salvageable.
Scintillator
WLS
10cm
phototube
light pipe
Light reflected 90o at polished 45o cut
Worries part 2 C. Woody pointed out radiation
hardness problem with plastic scintillator Serious problem start: 100’s
krad 10’s Mrad Run geant4.4 with simple Fe-
Sci calorimeter. Look at energy deposition in scintillator as a function of upstream interaction length.
Results: Assume 100 million dA
events. Every event fully fragments
the nucleus All protons hit one of the
calorimeter modules ~ 1krad
Other calorimeters
Cu calorimeter from Woody. 4 modules ~physical size of black
proton region. Looking into details this week.
E864 calorimeters from Sandweiss Pb-Sci fiber 10cm x 10cm face 750 modules
EE
E %34%5.3
Next
Check out Cu calorimeter this week Learn more about 864 calorimeter this week Mike and I travel to FNAL on Friday to begin
testing of Fe-Sci modules Road trip to BNL in March.
Serious simulation in Geant. How muddied is the signal by multiple-scattering? Have geometry files from Alexei in hand. Results by
next month.
Decision on calorimeter by March
People, DAQ, and $$’s People
~1-2 FTE physicists SCJ + fraction of Jane/Mike/Ron
1 tech-month Stand & other hardware construction
1 DAQ Expert for 1-2 Months DAQ
Relatively simple needs – shouldn’t stress the DAQ Specifics unclear to me -- need to bring ourselves up to speed on the
DAQ requirements. $$’s
LLNL grant: LLNL physicists, small hardware purchases, few thousand $’s for DAQ hardware, and 1 tech-month
BNL: Physical space XXX: DAQ expert Anything extra: ??
Schedule
If you’ve been listening to this talk, you know the schedule as well as I do.
ID Task Name Duration
1 Simulations 2 mons
2 Calorimeter testing 1 mon
3 Final Choice of Detector 0 days
4 Ship to BNL 2 wks
5 Hardware construction 2 mons
6 Testing 2 mons
7 Integration with DAQ 2 mons
8 Calibration 1 mon
9 Run III Starts 1 day
3/14
2/10 2/17 2/24 3/3 3/10 3/17 3/24 3/31 4/7 4/14 4/21 4/28 5/5 5/12 5/19 5/26 6/2 6/9 6/16 6/23 6/30 7/7 7/14 7/21 7/28 8/4 8/11 8/18February March April May June July August