# Presentation: 763046

## PHENIX Run7 Update

- Mike Leitch, LANL
- PHENIX Run Coordinator
- RHIC/AGS Users Meeting
- 21 June, 2007

- reaction plane

- PHENIX - MJL

- 6/21/2007

## Run7 Chronology

- Originally hoped to start with Nov 1st cool-down and PHENIX planned for:
-  AuAu – 15 wks (1.1 nb-1), pp – 10 wks (32 pb-1)
- Delayed by continuing resolution & meager
-     FY06 level to match
- But PHENIX started anyhow:
- Cosmic rays starting Jan 9th
- “Run7 is on” Feb 1st
- Start of cool-down Feb 8th
- Cryo problems Feb 24th
- Rings cold & with beam Mar 13th
- Start of Physics Mar 27th
- End of Run7 Jun 26th
- 13 wks of physics (Mar 27th – Jun 26th)

- PHENIX - MJL

- 6/21/2007

## PHENIX Physics Goals  for Run7

- Increase statistical & systematic precision of rare signals in AuAu, e.g. J/, jet correlations, etc
- Increase reach in pT, especially with PID from new TOF-West detector (pT > 8 GeV/c)
- Identified particle spectra
- Identified leading particles in jets
- Factor of two or more improvement in Reaction Plane resolution - valuable to many signals
- v2 for J/,  - new
- electrons, hadrons – extended
- Low-mass lepton pairs with the HBD

*simulation*

*Submitted to PRL*

- PHENIX - MJL

- 6/21/2007

## Four New Detector Subsystems for Run7

**TOF-W**

**RXNP**

**HBD**

**MPC-N**

- PHENIX - MJL

- 6/21/2007

## PHENIX Reaction Plane Measurements Now from MPC, RXNP & BBC

- PHENIX Reaction Plane Measurements Now from MPC, RXNP & BBC

**Reaction Plane Detector**

- PHENIX - MJL

- 6/21/2007

## TOF-West Particle Identification

- PHENIX - MJL

- 6/21/2007

## 4.5 Billion Min-bias events

- 711 b-1
- (3 x Run4)
- Projection for Run7 total  ~750 b-1

- PHENIX - MJL

- 6/21/2007

## 16%

**beginning**
**of store**

**end**
**of store**

- from yellow beam

- from blue beam

- Effects of Stochastic Cooling at PHENIX

- Improvement in integrated luminosity for PHENIX with Stochastic Cooling (SC)
**16%**

- PHENIX - MJL

- 6/21/2007

## Slide 9

- PHENIX - MJL

- 6/21/2007

## PHENIX Triggering & fast analysis for Run7

- Level-1 Triggering just Minimum-Bias  (+UPC)
-  5 kHz event rate through DAQ
-  only small fraction of integrated luminosity missed due to rates above the DAQ limit in the 1st 1⁄2 hour or so of stores
- Level-2 filtering in ATP’s producing selected, parallel sample of enriched events for fast processing
-  J/  ; J/  ee; high-pT level-2 triggers
-  10% of raw data size
-  sent to CCF in France via GRIDFTP
-  analyzed in France for fast results
- 10% of min-bias events sent to Vanderbilt for fast analysis of min-bias
-  for physics not provided by level-2 triggers
-  & min-bias events needed for mixing, etc to support level-2 analysis
- Counting house machines for fast HBD analysis

- PHENIX - MJL

- 6/21/2007

## PHENIX Data Acquisition (DAQ)

- DAQ Advances:
-  level-2 code speedup
-  additional buffer box
-  fix SEB memory leaks
-  more compact HBD data format
-  etc

- Present DAQ performance:
-  up to 5 khz event rate & 700 Mb/sec throughput

- PHENIX - MJL

- 6/21/2007

## (plot from Tom Throwe)

- PHENIX - MJL

- 6/21/2007

## PHENIX Shakedown/Cosmic Ray Running

- (Jan & Feb)

- Need Cosmic Ray background measurement for W physics
-  Cosmic/W estimated to be 1/1 for p>=10 GeV, but estimate is unreliable – need measurement!
- Also Cosmic ray in EMCal looks much like high-pT photon

- PHENIX - MJL

- 6/21/2007

## J/’s in AuAu Collisions at PHENIX

- PRL98, 232301 (2007)

- Statistical & systematic precision of new Run7 AuAu data will improve this picture – But will also benefit enormously from new dAu data that can constrain the cold nuclear matter baseline accurately

- J/’s in AuAu Collisions at PHENIX

- PRL96, 012304 (2006)

- PHENIX - MJL

- 6/21/2007

## Expected Results for J/ flow from Run7

- Expected Results for J/ flow from Run7

- PHENIX - MJL

- 6/21/2007

## for ~8% of present Run7 integrated luminosity

**for ~8% of present Run7 integrated luminosity**
**(~16,000 J/******** ******** ******** for present luminosity sum)**

**J/******** ******** ******

- unlike-sign pairs
- like-sign pairs (randoms)

*thanks to Catherine Silvestre*

- PHENIX - MJL

- 6/21/2007

## J/  ee

**J/******** ******** ee**
- for roughly 60 b-1
- scales to 5,000 or more J/ for present luminosity

- thanks to  Ermias Atomssa

- PHENIX - MJL

- 6/21/2007

## 0’s & ‘s

- 0’s & ‘s
- thanks to Justin Franz
- from about 16% of present data

******0**

****

- extended range in pT

- PHENIX - MJL

- 6/21/2007

## Hadron Blind Detector (HBD)

- Dalitz rejection via opening angle
- Identify electrons in field free region
- Veto signal electrons with partner
- HBD: a novel detector concept:
- windowless CF4 Cherenkov detector
- 50 cm radiator length
- CsI reflective photocathode
- Triple GEM with pad readout
*The HBD will improve our S/B**by a factor of ~100*

*Submitted to PRL*

- PHENIX - MJL

- 6/21/2007

## Hadron Blind Detector (HBD)

**electrons**

**hadrons**

- PHENIX - MJL

- 6/21/2007

## Concluding Remarks

- Near 3 times Run4 luminosity (~750b/241b) PLUS new capabilities from new detectors – major advances in our physics should result
- Analysis in progress already thanks to level-2 filtering & mature analysis model
- HBD a very state-of-the-art detector, but lessons learned in Run7 should allow full operation in Run8 & beyond
- Excellent stores when they could be delivered, but too many breakdowns
- Stochastic cooling - a step towards the future
- Low energy (9.2 GeV) running feasible
- Thanks to our CA-D colleagues for all their unending work to keep us & the machine working!
- And of course to all my colleagues on PHENIX who were the ones who really made things work at the counting house

- PHENIX - MJL

- 6/21/2007

## Backup

- PHENIX - MJL

- 6/21/2007

## PHENIX Reaction Plane Detector (RXNP)

**PHENIX Reaction Plane Detector (RXNP)**
- 200GeV Au+Au collisions
- RUN7 - 2007/Mar

- PHENIX - MJL

- 6/21/2007

## Luminosity fraction captured by PHENIX DAQ saturation in red

- Luminosity fraction captured by PHENIX DAQ saturation in red
- Fraction of luminosity for  late April stores (at bottom)
-  97.8% for 4.8 khz DAQ rate
-  for 1⁄2 hr turn-on time

- 6 min

- 21 min

- 18 min

- 16 min

- 32 min

- 26 min

- 0 min

- starts at
- 10 am
- Fri Apr 27th

- PHENIX - MJL

- 6/21/2007

## Improvement in integrated luminosity for PHENIX with Stochastic Cooling (SC)

| date | time | store | cooled | b-1/hr | Zdc
(pk) | FM
(x10-3) |
| --- | --- | --- | --- | --- | --- | --- |
| 5/15 | 2:10 | 8776 | no | 0.9804 | 34.97 | 28.04 |
| 5/30 | 2:10 | 8875 | no | 0.8789 | 32.07 | 27.41 |
| 5/30 | 23:50 | 8879 | no | 0.9746 | 34.85 | 27.97 |
| 5/19 | 14:47 | 8805 | yes | 1.1524 | 35.19 | 32.75 |
| 5/25 | 16:30 | 8849 | yes | 0.9874 | 30.34 | 32.54 |
| 6/1 | 8:00 | 8886 | yes | 1.0530 | 33.24 | 31.68 |

- Store 8879
- (no cooling)

- Store 8886
- (cooling on)

- PHENIX - MJL

- 6/21/2007

## Effects of Stochastic Cooling at PHENIX

- beginning
- of store

- end
- of store

- from yellow beam

- from blue beam

- PHENIX - MJL

- 6/21/2007

## Differentiation of vertex into distinct peaks due to Stochastic Cooling

- T. Roser’s vertex shape

**ZDC vertex (ZDC Wide)**
**BBC vertex (BBC no vertex cut)**
**BBC vertex (BBC ****±****30 cm vertex cut)**

- PHENIX - MJL

- 6/21/2007

## PRDFs

- Raw  data files
- GridFTP to VU
- 30 MBytes/sec

- 1

- 3

- 4

- 2

- nanoDSTs

- Reconstruction
- 200 jobs/cycle

- 45TB and 200 CPUs
- Available for Run7 Reconstruction

- 4.4TB  of buffer disk space

- Dedicated GridFTP Server*Firebird*

- 18 hours/job

- 770 GBytesper cycle

- nanoDSTs
- Reco output to RCFGridFTP 23 MB/sec

- RCFRHIC computing facility

- PHENIX - MJL

- June 13, 2007

## HBD Status 

- We believe we have determined the main cause of the sparking problems with the both detectors:
- Normal GEM spark would cause Lecroy HV to trip
- Mesh also trips leaving large stored energy on filter capacitor
- As GEM voltage goes to zero, large DV develops across gap between top GEM and mesh, ultimately resulting in a large spark
- This spark induces sparks in other GEMs (massive trips) by propagation  of scintillation light
-    There is however a danger in the “One source of all troubles” theory and we are still looking for more possible causes of the problems we had during the run

- from
- T.Hemmick

- PHENIX - MJL

- 6/21/2007

## Pock Marks

**Human eye could see the holes.**
**Holes smaller than pock parks.**
**Pocks almost certainly from mesh********GEM**

- from
- T.Hemmick

- PHENIX - MJL

- 6/21/2007

## Low Energy Running at PHENIX

- 9.19 GeV/nucleon
- PHENIX RXNP trigger
- timed in at full energy
-  expect ~96% efficiency (compared to ~15% for BBC)
- ZDC trigger should be very inefficient due to large Fermi motion wrt longitudinal momentum

-  Wednesday afternoon could run our DAQ with the “blue low-energy clock”
-  But Thursday morning, when beam was in the rings, we could not
-  Presumably due to glitches in the clock (associated with other clock events that were not there on Wednesday??)

- PHENIX - MJL

- 6/21/2007