1. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter1 Radiation hard Shashlik calorimeter for COMPASS experiment Vladimir Polyakov Institute for High Energy Physics, Protvino

2. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter2 Outline 1.The COMPASS experiment 2.Requirement and motivation 3.Design of spiral Shashlik module 4.MC and beam test results of the Shashlik prototype 5.Mass production of Shashlik modules 6.Conclusion

3. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter3 The COMPASS experiment Common Muon Proton Apparatus for Structure and Spectroscopy 2 nd spectrometer 1 st spectrometer SM1 magnet SM2 magnet 50 m ECAL1 ECAL2 First electromagnetic calorimeter dimension: 4.0 x 2.9 m 2, ; 1500 channels, three types of lead glass blocks 38x38 mm 2, 75x75 mm 2, 142x142 mm 2 ; central hole 1.1x0.6 m 2 ; angular acceptance 180x130 mrad Second electromagnetic calorimeter (GAMS-4000 detector, since 1980 at CERN, NA12 and WA102) dimension: 2.6 x 2.0 m 2, ; 3000 channels ; Spiral Shashlik and lead glass blocks, 38x38 mm 2 ; Muon beam: data taking 2002-2007 Intensity 2x10 8 spill -1 Hadron beam: data taking 2008-2009 Intensity 5x10 7 spill -1

4. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter4 Limitation for ECAL2: Radiation dose 350 days running, 190 GeV hadrons, 5x10 7 /spill, maximal dose – 40 krad ECAL2 before 2008 Total number of channels – 3068, 38.2x38.2mm lead glass blocks ~800 radhard blocks Radiation thickness – ~16 X 0 Radiation hardness – 400 rad for lead glass blocks 3 krad for radhard lead glass blocks Energy resolution – 6%/(E) 2% for lead glass blocks 6%/(E) 4% for radhard lead glass blocks Minimal angle – 0mrad Maximal angle – 40mrad (horiz.) and 30mrad ( vert.)

5. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter5 350 days running, hadron beam 190 GeV, 5.0 10 7 /spill Rad 4000 400 40 Need additional 900 rad hard blocks 2 krad 400rad

6. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter6 Radiation hardness 500 krad Energy range 1÷190 GeV Energy resolution Radiation thickness 23 X 0 Uniformity 1÷2% for angular range 0-40mrad Module size 38.2x38.2 mm 2 Module length 450 mm COMPASS requirements for radhard calorimeter: 1.PWO crystals – very high price, radiation instability for low dose; 2.Shashlik calorimeter – bad energy resolution and uniformity for small angles (up to 50mrad)

7. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter7 ZEUS Shashlik EM-calorimeter; NIM A: 450 (2000) no. 2-3, pp.235-252. ~25%~15% e ±, p,n

8. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter8 Spiral Shashlik module Dimensions38.2x38.2 mm 2 Radiation length17.5mm Moliere radius 36mm Radiation thickness 22.5 X 0 Scintillator thickness1.5mm Lead thickness0.8mm Radiation hardness 0.5 Mrad Energy resolution6.5%/E 1%

9. Calo meeting, 26 October 2010V.Polyakov, Shashlik beam tests9 Spiral Shashlik 1mm 1.4mm 2mm 22.5 0 Sampling – 0.8 mm lead and 1.5 mm scintillator; 4x4 fibers, 4 steel rods; 155 layers 4 types of scintillators and 2 types of lead plates

10. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter10 ECAL2, Run 2003 1000 blocks remove780 radiation hard blocks installECAL2, Run 2008, 64 48 GAMS lead glass blocks, 2 2 blocks central hole 864 Shashlik modules 768 radhard GAMS blocks GAMS blocks 1440 GAMS blocks

11. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter11 ECAL2, Run 2003 1000 blocks remove780 radiation hard blocks install3 types of modules that are used in ECAL2 calorimeter Shashlik modules radhard GAMS lead glass blocks GAMS lead glass blocks

12. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter12 Energy resolution (T9 and H4 beam tests) σ E /E = a/E b c/E σ E /E = a/E b

13. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter13 Uniformity, 4GeV electrons

14. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter14 Uniformity, 70GeV electrons

15. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter15 Profile for 10 GeV photons R M = 36 mm

16. TB, February 2011VP, Shashlik16 0 from real data; Shashlik shows 30% better resolution compared to lead glass

17. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter17 Mass production Radiation hardness of scintillators was measured up to 250 krad Loading test No changes in light yield and attenuation after 4 month of loading with 120 kg Online control: The spread of light yield for scintillators is less than 3% The spread of the thickness of lead is less than 80μk ( 10%) Measurements of light yield and attenuation length for each spiral Shashlik modules Attenuation length > 1.7m Light yield > 400 photoelectrons per MIP Production speed – 200 modules per month

18. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter18 IHEP Scintillator Fasilities www.ihep.ru/scint/index-e.htm

19. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter19 Mould Scintillators

20. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter20 Scintillators

21. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter21

22. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter22 Conclusion The new type of the Shashlik calorimeter were design and developed; 900 spiral Shashlik modules for upgrade of second electromagnetic calorimeter of COMPASS experiment are produced; Spiral Shashlik calorimeter is adequate the requirements of COMPASS;

23. NA62, 21 October 2010V.Polyakov, Shashlik calorimeter23 Spiral Shashlik module