Report from NA61/SHINE measurements for 7Be + 9Be at CERN/SPS energies

GDR 2010, 30th April, Paris

Roman PłanetaJagiellonian University, Kraków

for the NA61/SHINE collaboration

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run 15012, 150A GeV/cevent 417

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p+p

Be+Be

Ar+Ca

Xe+La

Pb+Pb

p+Pb 13 20 30 40 80 160

2012/14

2014

2015

2011-2012

2009/10/11

energy (A GeV)

13 20 30 40 80 160

Pb+Pb

p+p

C+C

Si+Si

energy (A GeV)

NA61 ion program NA49 (1996-2002)

Data sets recorded and to be recorded by NA61 within the ion program

Detector

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Main upgrades:

TPC read-out - an increase of the data rate by a factor of 10 compared to the NA49 rate

TOF-F detector - acceptance X 2

Projectile Spectator Detector - with a resolution of 1 nucleon

He beam pipe - reduction of the δ-electron background by a factor of 10

Z-detector - measure ion charge for on-line selection of secondary ions

A-detector - measures mass compositionof secondary ion beam

Secondary Be beam: basic idea

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Pb

primary Pb beam

from the SPS

Pb fragmentsfragmentationtarget

fragmentseparator

Fragmentation target (T2) length optimized to the desired fragment production

The beam line is a double spectrometer with 0.04% resolution that helps to separate ion fragments corresponding to a selected magnetic rigidity Bρ

• Degrader (Cu plate where ions lose energy dE/dx ~ Z2) allow to reach required beam purity at lower energies

Secondary Be beam: fragment separator

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T2 target18 cm, Be

Degrader1 cm, CudE/dx ~ Z2

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Projectile and target

9Be target:

• thickness 1.2 cm for most of the runs• only for 75A GeV/c runs the 1.2 and 0.3 cm 9Be targets were

used, interaction probability: 8% and 2%, respectively

7Be projectile:

• long living isotope of beryllium• 6Be unstable, for 8Be T1/2 ≈ 10-16 s

1.2cm * 2.5 cm * 2.5 cm

Time structure of the beam

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• The complete SPS revolution time is 22.7 μsec.• Presently we have 2 injections. An

injection results in a batch.• The batches contain about 3*10+8 ions.• The batches are spaced by 8 μsec.• The batches contain 2 bunches.• The bunches are spaced by 200nsec

inside a batch.

Beam properties measured by Beam Position Detectors (BPD)

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75A GeV/crun 15101

Beam tracks – BPD2 to end of MTPC

40A GeV/crun 15268

Z - detector

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Be/all = 11.2%

Be/all = 6.9% Be/all=4.0%

Quartz Cherenkov detector

A - detector

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scintillator read-out by two PMTs, measures mass and charge of ions (tof and Z2 ) , located 140 meters upstream of the NA61 target

σ(tof) ≈ 100 ps

11C 12C

75A GeV/cRun 15161, target IN

A-det versus Z-det

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7Be

PSD – Projectile Spectator Detector

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44 modules 2011: 32 modules

(16 small and 16 large)

Used in the trigger

Precise measurement of the energy of projectile spectators.• centrality selection (on trigger level)• measurement of event-by-event

fluctuations (to reduce Npart fluctuations)

• Reconstruction of the reaction plane

• Compensating calorimeter• Pb/scintillator (4/1)

sandwich• Modules 10 x 10 x 120 cm3 and 20 x 20 x 120 cm3

Ready in 2011 for the high SPS energies ,to be extended in 2012 for the low SPS energies

Trigger definitions

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Triggers used

Trigger Definition Scaling factor

T1 S1*V0bar*V1bar*V0’bar*Z(Beryllium) 200

T2 S1*V0bar*V1bar*V0’bar*Z(Beryllium)*PSD 1

T4 S1*V0bar*V1bar*V0’bar 2000

T1 – Be beam triggerT2 - interaction triggerT4 – beam trigger

BPD1 BPD2 BPD3

S1 V0 V0’ V1Z-detector Target

Beam

PSD performance

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40A GeV/cRun 15258 special, target INtrigger S1

75A GeV/cRun 15161, target INBeam trigger

150A GeV/cRun 14946, target OUTAll triggers

Beam momentum(A GeV/c) 40 75 150 Etotal (GeV) Resol. ( %) Etotal (GeV) Resol. (%) Etotal (GeV) Resol. (%)2H 80 11.8 150 9.2 300 6.64He 160 8.1 300 7.0 600 6.77Be 280 6.4 525 6.1 1050 4.1

BeBe

BeHe He

He

Correlation of PSD energy versus Z-det

Spectrum of PSD energy for all triggers

d He

Be

75A GeV/cRun 15161, target IN7Be

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W/o Z cutsBeam trigger

Z cuts are appliedBe beam trigger

Energy in PSD

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75A GeV/cRun 15161 target IN

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Energy in PSD

7Be beam trigger

7Be beam trigger

7Be beam trigger

7Be + 9Be @ 150A GeV/c, run 15012

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event 381, low multiplicity

event 417, medium multiplicity

event 515, high multiplicity

TPC tracks

Pb + Pb @ 80A GeV/c

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TPC tracks

7Be + 9Be @ 150A/c GeV

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TPC vertex position

2011 Be run: data statistics

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16.00 21.00 26.00 31.00 36.00 41.000

2000000

4000000

6000000

8000000

10000000

12000000

14000000

Be 40 GeV/c

Pb 80 GeV/c

Be 150 GeV/c

Be 75 GeV/c

16.11 21.11 26.11 31.11 5.12 10.12

2011 Be run: data statistics

• Be+Be at 150A GeV/c : 3.12 M events • Be+Be at 75A GeV/c : 5.09 M events

• Be+Be at 40A GeV/c : 3.39 M events

• Pb+Pb at 80A GeV/c : 141 k events

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Summary

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the data taking for Be+Be interactions at 40A, 75A and 150A GeV/c was completed as planed

performace of all subsystems during the Beryllium run was good

Be+Be measurements for 13A, 20A and 30A GeV/c will be conducted in 2012 performace of our experimental set up for measurements with primary Ar and Xe beams in 2014 and 2015 was tested using Pb+Pb collisions at 80A GeV/c

The NA61/SHINE Collaboration

University of Athens, Athens, GreeceUniversity of Belgrade, Belgrade, SerbiaUniversity of Bergen, Bergen, NorwayUniversity of Bern, Bern, SwitzerlandKFKI IPNP, Budapest, HungaryJagiellonian University, Cracow, PolandJoint Institute for Nuclear Research, Dubna, RussiaFachhochschule Frankfurt, Frankfurt, GermanyUniversity of Frankfurt, Frankfurt, GermanyUniversity of Geneva, Geneva, SwitzerlandForschungszentrum Karlsruhe, Karlsruhe, GermanyInstitute of Physics, University of Silesia, Katowice, PolandJan Kochanowski Univeristy, Kielce, PolandInstitute for Nuclear Research, Moscow, RussiaUniversity of Nova Gorica, Nova Gorica, SloveniaLPNHE, Universites de Paris VI et VII, Paris, FranceFaculty of Physics, University of Sofia, Sofia, BulgariaSt. Petersburg State University, St. Petersburg, RussiaState University of New York, Stony Brook, USAKEK, Tsukuba, JapanSoltan Institute for Nuclear Studies, Warsaw, PolandWarsaw University of Technology, Warsaw, PolandUniversity of Warsaw, Warsaw, PolandUniveristy of Wroclaw, Wroclaw, PolandUniversidad Tecnica Federico Santa Maria, Valparaiso, ChileRudjer Boskovic Institute, Zagreb, CroatiaETH Zurich, Zurich, Switzerland

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Additional slides

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PSD spectrum – calibration of scale

2H-253 GeV

4He- 520 GeV

7Be-1024 GeV

E1n(7Be)=150 GeV

But

E1n(4He)=130 GeV

Why?

The reason is rigidity of beam r=P/Z=const.

P1n(4He)x4/2=P1n(7Be)x7/4

P1n(7Be)x7=P1n(4He)x4/2x4=P1n(4He)x8VIII-th Polish Workshop on Relativistic

Heavy-Ion Collisions 26

He beam pipe

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He

CO2Ar+CO2

30 mm Tedlar

• Measurements show significant decrease of secondary interactions with He beam pipes installed

Without He beam pipes

With He beam pipes

Position of the reconstructed interaction point along the beam directionp+p collisions at 158 GeV