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