Status of the Calorimeter Working group activities GSI, 16 th October 2007

NUSTAR CALORIMETER Working Group Coordinator : D. Cortina R3B (D.Cortina) / EXL (J.A. Scarpaci) Created in : February 2005 after the NUSTAR collaboration Goal: Find synergies between the different calorimeters in NUSTAR (R&D, Desing phase, but also common front to negociate with providers) List : 41 members, 21 Institutions, 10 countries, Meetings - February 2005 GSI, Darmstadt (Germany) - June 2005 Valencia (Spain) - Informal meeting, September 2005, Orsay (France) - September 2005 Santiago de Compostela (Spain) - February 2006, IPN Orsay (France) - September 2006, Krakow ( SPIRAL) *

Last year activities  R3B/EXL collaboration working group, Milan October 2006  CWG meeting, Nustar week, GSI March 2007  Prototype definition videoconference, May 2007  CWG meeting, Lund June 2007  Working progress videoconference, September 2007  CWG meeting, GSI October  calorimeter

Total absorption efficiency 80 % (E  =15 MeV lab R3B) (E  =2-4 MeV lab EXL) Very large crystals E  sum  (E sum )/ <10%  Multiplicity  (N  )/ < 10%  E/E for  MeV Scintillation properties Detector granularity  E/E for p (up to 300 MeV) Calorimeter for p 1 %Large crystals Dynamic range Large dynamical range for detecting p,  Inner radius ~ 30 cm ( house Si trackers) UHV compatible for EXL Affordable cost!!! Technical Proposal (2005)

Gammas are emitted with energies up to E lab = 3.2 E CM (for β = 0.82 ~ 700 A. MeV) ✗ A huge crystal length is required for full energy absorption The angular distribution of the emitted gammas is peaked in the forward direction. ✗ allows a certain optimization of the angular coverage E CM = 10 MeV ( β = 0.82) Experimental constraints The forward angular region will be the most delicate part

Calorimeter sectors E CM = 10 MeV β = 0.82 Angular distributionDoppler shift BARREL FORWARD ENDCUP

R&D working group activities  General design studies (R3B) barrel: IPNO,USC forward endcup: IPNO,USC  R&D on Crystals and photosensors barrel: IPNO,USC, Lund forward endcup: Madrid  Simulations (R3B) full calorimeter : USC partial : Lund, Madrid

R&D working group activities  Mechanical structure cell structure: IPNO,USC, TU-Vigo general mechanical support NN  Prototypes barrel: IPNO,USC, Lund forward endcup: Madrid  Electronics NN  Slow control and monitorisation NN

General design: R3B Calorimeter models (CAD) v1.2 v4.0a v4.0b v4.0c USC, IPN

General design: R3B Calorimeter models (CAD) Inner radius 30 cm Few crystal shapes Garantees DE/E~ 3% (due to polar angular resolution) H. Alvarez, USC v5.0 Last accepted version for the barrel design

Crystal and photosensors !?

Crystal and photosensors BARREL CsI(Tl) + PM IPNO (0,0,0) z x Beam axis 14° Target 1450mm R3B Calorimeter 2.2T Magnet ~300 Gauss at PM level  PROBLEM Good energy resolution Shielding needed to work with PM

Crystal and photosensors CsI(Tl) + LAAPD USC Very good energy resolution Variation of APD gain with temperature  monitorization needed

Crystal and photosensors CsI(Tl) + PD LunD Moderate energy resolution Very high threshold  problem to register low energy gammas

Crystal and photosensors CsI(Tl) + PD LunD excelent energy resolution for 180 MeV protons Huge contribution of nuclear interactions and multiple scattering Uppsala, TSL, GWC, B-line (Blue hall): Energy ±0.80 MeV.

the estimated final energy is proportional to the energy deposited in each layer  need to be proven from measurements and simulations E Ë=  f(  E 1 ) + g(  E 2 )  E 1  E 2 M.Turrion, O.Tengblad IEM LaBr3(Ce) of 30 mmLaCl3(Ce) of 150 mm Crystal and photosensors Forward endcap LaBr + PM  not yet investigated Two layer detectors IEM, Chalmers

Calorimeter models (GEANT4) Detailed simulations v1.2v4.0a v4.0b H.Alvarez USC Allowed very valuable information - geometry  efficiency and granularity - tracking algorithm tests etc etc….

Barrel Prototypes CsI(Tl) + LAAPD Hamamatsu 2x S

 Realistic frustum-shaped crystals: Lanzhou Hilger St. Gobain (France and India) Scionix  LAAPDs Hamamatsu 2x(10x10) mm 2 Materials

Square PMT Photonis (1 per 2 crystals) Rectangular Crystals Barrel Prototypes

In 2008, construction of a prototype of 18 Xtals [CsI(Tl)] with 9 square PMT Simulation and Tests of the prototype with different thickness of material in between the crystals depending on mechanical and physics considerations. Barrel Prototypes

Time schedule (R3B) Info from 2006  extension of ~ 1 years

Conclusions  Good way towards the definition of the barrel design CsI(Tl) + PM /LAAPD First detectors (realistic size) will be mounted next weeks Prototypes ready around summer 2008 Different facilities are considered to perform in beam test with these prototypes  Detection in forward sector is still a real challenge We need to investigate in detail the proposed solutions and/or find alternatives Urgent to address this problem within next year  Technical man power is needed mechanical structure electronics and slow-control is not yet addressed  We are lacking the support of big laboratories Not yet urgent today but mandatory for the construction phase