parma, 23 settembre 2010 lhcf status report oscar adriani università degli studi di firenze infn...

Parma, 23 Settembre 2010

LHCf status report

Oscar AdrianiUniversità degli Studi di

FirenzeINFN Sezione di Firenze

Oscar Adriani 23/09/10

Experimental set-upExperimental set-up

Detectors installed in the TAN Detectors installed in the TAN region, 140 m away from the region, 140 m away from the Interaction Point 1Interaction Point 1Here the beam pipe splits

in 2 separate tubes.Charged particle are swept away by magnets We cover up to y

INTERACTION POINT

IP1 (ATLAS)

Detector II

Tungsten

Scintillator

Silicon strips

Detector I

Tungsten

Scintillator

Scintillating fibers

Charged particlesCharged particles

Neutral particlesNeutral particles

Beam pipeBeam pipe

ProtonsProtons

140 m 140 m

n π0

γ

γ8 cm 6 cm


LHCf : Monte Carlo discriminationLHCf : Monte Carlo discrimination

106/107 generated LHC interactions at 7+7 TeV 1 minute exposure@1029 cm-2s-1 luminosity

n


LHCf Operations at 900 GeV06 Dec – 15 Dec 2009

27.7 hours for physics

~5x105 collisions at IP1

~2,800 shower events in Arm1

~3,700 shower events in Arm2

02 May – 27 May 201015 hours for physics

~5.5x106 collisions at IP1 (Statistics x 11 wrt 2009)

~44,000 shower events in Arm1~63,000 shower events in Arm2

Beam Gas significantly reduced wrt 2009


2009 vs 2010

2009 2010

Very big reduction in the Beam Gas / Bunch crossing ratio!!!!Very big increase of the ‘signals/noise’ ratio due to higher intensity


Arm1 Spectra at 900 GeV

MC normalized to the total number of events in the 2 towers,without PID.Only one normalizationfactor common to all models

Preliminary

Only statistical errors are quoted


Arm2 Spectra at 900 GeV

MC normalized to the total number of events in the 2 towers,without PID.Only one normalizationfactor common to all models

Preliminary

Preliminary

Only statistical errors are quoted


LHCf 2010 runs (mainly at 7 TeV)

• Detector shows good performance with stable quality.– Energy scale calibration with the 0 peak!!!!– Good stability < ±1% level. – We started to have some radiation problems in the

last periods.

• Thanks a lot to all LHC people for providing us 100 rad crossing angle!!! – Very important for physics to enlarge the PT

acceptance

• Detectors were removed on July 20, 2010


Acceptance gain due to Crossing Angle

Arm1Arm1

No crossing angle 100 rad crossing angle

A very significant gain in acceptance is clearly visible!


Operation at 7 TeVWithout crossing angle (30/03 – 05/06)With 100rad crossing angle (25/06 – 20/07)

Runs are taken in many different vertical position and with/without Xing angle


7 TeV collisions

Y-view of silicon strip

X-view of silicon strip

Transition curve in towers

1 TeV gamma-ray shower @ Arm2


0 at 7 TeV

Arm2 event display

Silicon layers

Scintillator layers

To

wer

32m

m

25m

m

Robust sample Good energy calibrator

25 mm tower

32 mm tower


Beam position analysis: LHCf vs BPM


M/M=6.3MeV/135MeV=4.7%

0 mass and energy spectrum (Arm1)

Please note the Very High Energy!

Preliminary

Preliminary

Preliminary


0 mass and energy spectrum (Arm2)

M/M=2.3%

Using only data taken before April 13th

Preliminary

Preliminary


Particle ID: L90%


PID study Energy spectra with not PID biasedEnergy spectra with not PID biased

By fitting the L90% distribution with the superposition of 2 components (gamma-rays and hadrons), the efficiency and purity can be estimated from the data themselves.

Before the correctionAfter the correction


Measured Spectra at 7TeV

preliminary preliminary

Gamma-ray likeGamma-ray likeHadron likeHadron like

Arm2Arm2

preliminarypreliminaryGamma-ray likeGamma-ray like Hadron likeHadron likeArm1Arm1

Very high statistics !! only 2% of all data


Arm1/Arm2 Comparison

Red : Arm1Blue : Arm2

Red : Arm1Blue : Arm2

• Same geometrical regions and same runs are selected

• Correction for different livetimes


search

All data taken with zero-crossing angle and low luminosity

In the High Lumi/High Pile Up runs we don’t see (combinatorialbackground)


Luminosity with VdM scan with Front Counter Data

σx & σy are measured in VdM scan (May 9th)

independently from interaction model or detector

Calculate luminosity with this VdM scan

Calculate “FC rate Luminosity” Conversion Factorto be independent from MC

L f revnbN1N2

2 x y


VdM scan May 9th, 2010 FC rate of arm1 / 1000

Beam position - start of scan +0.3mmBeam position - end of scan +0.3mm

Scan FC1 FC2 FC1&2 ATLAS

Scan 005

59.8μm 59.9μm 58.4μm 59.1μm

Scan 006

60.0μm 60.3μm 59.1μm 59.3μm

x measured by FC

Horizontal scan

Lumi measured perfectly compatible with Atlas!

+


Radiation Damage

3%

Dose measured by the dosimeters behind the calorimeters

0 mass peak


LHCf removal• LHCf has completed the basic physics

program at 7 TeV • LHCf has been removed on July 20th,

during a short technical stop (a little bit

)

• Laser calibrations were done for few weeks after the removal (Annealing)

• Test beam is foreseen from October 15 to 28– 3 days main users– 10 days parasitic run


Future activities (I)

2011 – Replace plastic scintillators with Rad Hard

GSO (prepared by Japan side) in Florence Clean Rooms

– Produce 2 new silicon modules to replace partly defective ones + 2 spares

– Modify the silicon layers positions to improve silicon-only energy resoution

– Test beam at SPS to calibrate Arm1&Arm2– Test beam at GSI to intercalibrate the Silicon

Pace3 response with relativistic High Z Nuclei


R&D for the detector upgrade.

Plastic scintillators (EJ260)Plastic scintillators (EJ260) ⇒ ⇒ GSO scintillators GSO scintillators

EJ260

Radiation damage measured by Ion beams

Scintillating Fibers ⇒ GSO bars

MIP peak


New silicon layers arrangement

8 Silicon Layers 6 6 12 12 18 26 34 42 X0


Future activities (II)• 2012

– Install the detectors at RHIC?– RHIC can accelerate:

• p-p up to 250 GeV/nucleon• Ions up to 100 GeV/nucleon• They have already done deuteron-Gold• They could do p-Light ion

– RHIC beam pipe arrangement• Situation similar to LHC• Single beam pipe split in 2 at 20 m from IP• Space available ~ 10 cm• LHCf can fit very well inside!

– 0 can be reconstructed as we are doing in LHC!

• Sqrt(s)min=4 m d/hdet • d=20 m, hdet = 8 cm Sqrt(s)min= 135 GeV

• More news in 2011—> Stay tuned!!!!!!!


Future activities (III)

• 2013-2014 – Re-install Arm1&Arm2 at LHC when the

energy will be raised to 13/14 TeV– Necessity to mantain the Cern

infrastractures:• Control room• Electronics pool material• Safety infrastructures• Racks in underground areas• Team account• Etc. etc. etc.


Conclusion

• LHCf has completed the basic physics program at 7 TeV

• LHCf was removed from TAN on July 20th, 2010• Test beam is foreseen in October 2010 • The detector will be upgraded during 2011 to

improve radiation hardness– GSO will replace plastic scintillator– More energy measurement oriented silicon

arrangement

• RHIC Option for 2012? Stay Tuned!!!!!!!!!!• LHCf will certainly be back in the TAN for the

14 TeV run!


Backup slides


Studies of detector responses

layer

dE

MC (DPMJET3)Measured

Silicon Tracker

LHCf Detector

Beam Pipe

Transition curve for 350GeV/c protonsDetector response for hadrons Detector response for hadrons by beam test data at SPS done in 2007by beam test data at SPS done in 2007

LPM effectLPM effectThe radiation length for high energy particles seems to become longer in the heavy matter. - Confirmation of the LPM effect - Effect to the energy reconstruction and PID etc.

Transition curve for 1.5TeV γ (MC)

presented by SAKO

protons with 350GeV/c and 150GeV/c⇔ LHC: 450GeV+450GeV

Presented by MASE


Alessia Tricomi Alessia Tricomi University & INFN University & INFN

CataniaCatania

The LHCf experiment at LHC The LHCf experiment at LHC ISVHECRI08, Paris 1-6 ISVHECRI08, Paris 1-6 September 2008September 2008

Radiation Damage StudiesRadiation Damage Studies

30 kGy30 kGy

•Expected dose: 100 Gy/day at 10Expected dose: 100 Gy/day at 103030 cm cm--

22ss-1-1

•Fewmonths @ 10Fewmonths @ 103030 cm cm-2-2ss-1-1: 10 kGy: 10 kGy• 50% light output50% light output•Continous monitor and calibrationwith Continous monitor and calibrationwith

Laser system!!!Laser system!!!

Scintillating fibers and scintillatorsScintillating fibers and scintillators

1 kGy1 kGy


Particle Identification

Thick for E.M. interaction (44X0) Thin for hadronic interaction(1.7)

Longitudinal development of shower Longitudinal development of Hadron shower

Definition of L90%

Gamma-rays:L90%<16 r.l. + 0.002 x dE


Results at 900GeV: PID

Gamma-rays:L90%<16 r.l. + 0.002 x dE

QGSJET2

Data

QGSJET2

Data

QGSJET2

Data

QGSJET2

Data

Preliminary


L90%<18X0

Constant cut


RHIC Physics Case

• p-Light Ion– This measurement will allow to directly

measuring the characteristic of the HECR-atmosphere interactions, without having to rely on the approximation usually done to go from the p-p collision to the p-nucleus collision (Glauber approximation).

• p-p – We propose also to run the RHICf experiment

in the p-p collisions, to have the possibility to directly check the validity of the Glauber approximation at 200 GeV center of mass energy by comparing the p-p with the p-LI results.


Beam Position Analysis from the LHC data

Theoretical center

Positive; upward in V outward in H

43m140m

BPMSW

BPMSWIP Offset; bθ

• Beam position (b) and angle (θ) can be determined from the measurements of two BPMSW (beam position monitor)

• Expected position (neutral center) on the LHCf detector at 140m away can be calculated from these numbers

• Analysis done by Simon White


FrontCounter as a good luminosity monitor

• FC is working very well for luminosity monitoring (Very useful monitor for the machine)

• Continuous monitoring w/ independent DAQ now available. See Page1 “LHCf experiment”

• Conversion to “luminosity” from FC rate is now under study by MC

Beam pipe

TANNeutral particles

FCLHCf-CAL

BR

AN

-Sci

ZD

CZ

DC

ZD

CB

RA

N-I

C

Gaussian fit

Arm1

Arm2

Coincidence

Stay all the time

lumiscan

Page1LHCf page


ATLAS online (w/o calibration)

VdM scanning

parma, 23 settembre 2010 lhcf status report oscar adriani università degli studi di firenze infn...

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