Status of the Calorimeter Working

group activities

GSI, 16th 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 2007

www.usc.es/genp/r3b calorimeter

Total absorption efficiency 80 % (Eg=15 MeV lab R3B)(Eg=2-4 MeV lab EXL)

Very large crystals

Eg sum s(Esum)/<Esum> <10%

g Multiplicity s(Ng)/<Ng> < 10%

DE/E for g 2-3 % @ 1 MeV Scintillation propertiesDetector granularity

DE/E for p (up to 300 MeV)Calorimeter for p

1 % Large crystalsDynamic range

Large dynamical range for detecting p,g

Inner radius ~ 30 cm ( house Si trackers)

UHV compatible for EXL

Affordable cost!!!

Technical Proposal (2005)

Gammas are emitted with energies up to

Elab

= 3.2 ECM

(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

ECM

= 10 MeV(β = 0.82)

Experimental constraints

The forward angular region will be the most delicate part

Calorimeter sectors

ECM = 10 MeV

β = 0.82

Angular distribution Doppler 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 axis14°

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 179.31±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( D E1 ) + g( DE2 )

DE1

D E2

M.Turrion, O.Tengblad IEM

LaBr3(Ce) of 30 mm LaCl3(Ce) of 150 mm

Crystal and photosensors

Forward endcap

LaBr + PM not yet investigated

Two layer detectors IEM, Chalmers

Calorimeter models (GEANT4)Detailed simulations

v1.2 v4.0a 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 S8664-1010

Realistic frustum-shaped crystals:

Lanzhou

Hilger

St. Gobain (France and India)

Scionix

LAAPDs Hamamatsu

2x(10x10) mm2

Materials

Square PMT Photonis(1 per 2 crystals)

RectangularCrystals

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