Prototype sPHENIX Calorimeters

1. Prototype sPHENIX Calorimeters John Haggerty Brookhaven National Laboratory

2. The sPHENIX Experiment • Major upgrade to the PHENIX Experiment at RHIC • Primary purpose is to measure jets in heavy ion collisions • Measure jet energy using calorimetry • Good solid angle coverage (|h|< 1, Df=2p) • Provide a basis for a future detector at eRHIC • Study nucleon structure and QCD in nuclei over a broad range of x and Q2 using deep inelastic polarized ep and eA collisions

3. Magnet HCAL EMCAL Solenoid

5. Calorimeter Requirements • Large solid angle coverage (± 1.1 in h, 2p in f) • Moderate energy resolution • EMCAL ~ 15%/√E • HCAL ~ 75 %/√E (single particle), ~100 %/√E (jet) • Compact (for EMCAL  small RM, short X0) • Physically small (dense) – occupies minimal space • High segmentation for heavy ion collisions • Hermetic • Projective (approximately) • Readout works in a magnetic field • Low cost

6. EMCAL Tungsten-SciFi Accordion SBIR Tapered thickness pure tungsten metal plates with scintillating fiber layer glued in between ~ 10 cm 18 X0 2 W plates/layer  0.6 X0 sampling Pure tungsten metal sheets (r ~ 19.3 g/cm3) Thickness: 2x1.0 mm Epoxy (~ 0.1 mm) Scintillating fibers 1.0 mm X0 = 5.3 mm RM = 15.4 mm

7. EMCAL prototype • Test of simpler “tilted plate” design • 1 mm W + 1 mm scintillator

8. 3x3mm SiPM Towers are formed by Light Collection Cavities White reflecting epoxy between plates 22 mm 3D printed light collection cavities 8x8 tower readout board with 2x7 light collection cavities

9. Light Yield From Fibers Light yield from prototype measured with cosmic rays and PMT readout 500 g/MeV energy deposit in scintillator 8 % sampling fraction  40 x 103g/GeV (Edep in calorimeter) Light Collection Factor (2%)  800 g/GeV SiPM PDE ~ 0.25  200 p.e./GeV  7%/√E contribution to energy resolution

10. sPHENIX Hadron Calorimeter 60 cm 3.5 labs 30 cm 1.5 labs 4 inner and 4 outer plates joined together to form one section • Steel plates with scintillating tiles parallel to beam direction • Steel serves as flux return • Steel plates are tapered •  Sampling fraction changes with depth • Divided into two longitudinal sections • Measure longitudinal center of gravity to correct for longitudinal fluctuations • Plates tilted in opposite directions to avoid channeling

11. HCAL Readout Scintillating tiles with WLS fibers embedded in grooves Fibers read out with SiPMs T 2x11 scintillator tile shapes 8 readout fibers per tower Outer readout SiPMs + mixers 2x11 segments in h (Dh =0.1) 64 segments in f (Df=0.1) 1408 x 2(inner,outer) = 2816 towers Inner readout (~10x10 cm2) Outer Inner

12. HCAL Scintillator Tiles Manufactured in Russia White reflective coating (chemical etching) WLS fiber embedded in grove in tile (top and bottom)

13. Light Collection for HCal

14. HCAL Tile Measurements at the University of Colorado Light output and uniformity measurements of scintillating tiles Top fiber Bottom fiber S.Beckman Light Yield ~ 18 p.e./”mip” (measured with 90Sr)

15. HCAL prototype

16. Beam Test of the Combined EMCAL/HCAL Prototypes Scheduled to take place in the MT6 test beam at Fermilab in Feburary 2014

17. sPHENIX

18. HCAL Prototype Construction at BNL

19. Readout Electronics EMCAL Prototype readout board HCAL Readout Electronics System

20. Electronic chain test

21. Calorimeter beam test

22. Summary • PHENIX is planning a major detector upgrade to replace its existing Central Arm Spectrometer with a new calorimeter system consisting of an electromagnetic and hadronic calorimeter • These new calorimeters will enable a detailed systematic study of jets produced in heavy ion collisions at RHIC to study the QGP near its transition temperature • Both calorimeter designs are well under way and prototypes of both calorimeters are currently under construction • A combined test of both prototype calorimeters is planned to take place at Fermilab in February of next year