Status of the Cylindrical‐GEM project for the KLOE‐2 Inner Tracker Danilo Domenici (INFN-LNF) on behalf of the KLOE-2 collaboration Villa Olmo, Como – 6 th October 2009

KLOE-2 Highlights 10/01/2016 Villa Olmo, Como D. Domenici - LNF2 KLOE-2 is going to continue and improve the KLOE physics program at the upgraded DaΦne machine with a focus on K S η and η’ rare decays, neutral kaon interferometry, lepton universality test and γγ physics End of 2009: roll-in of KLOE for 1 year of data-taking Spring 2011: upgrade of KLOE with new Calorimeters (QCALT, CCAL, HET) and a new Inner Tracker based on the GEM technology for a 2-3 years of data-taking The project has been approved and funded by INFN Other 4 talks presented in this Conference (Gonnella, Schioppa, Miscetti, Martini)

The KLOE Detector 10/01/2016 Villa Olmo, Como D. Domenici - LNF3 Multi-purpose detector optimized for K L physics Huge, transparent Drift Chamber in 5.2 kGauss field of a SC coil Carbon fiber walls, stereo wires, 2 m radius, 4 m long, He/CO 2 gas mixture Momentum resolution: σ(p T )/p T ~ 0.4% Pb-Scintillating Fiber Calorimeter with excellent timing performance 24 barrel modules, 4 m long and C-shaped End-Caps for 98% solid angle coverage Time resolution: σ T = 54 ps / √E(GeV) ⊕ 50 ps Energy resolution: σ E /E = 5.7% / √E(GeV) Drift Chamber Calorimeter

Need for an Inner Tracker 10/01/2016 Villa Olmo, Como D. Domenici - LNF4 Simulation results for a π track from K S → ππ Δp IT0.6 mm0.9 mm 1.2 MeV/c 1.9 mm No IT 1.7 mm2.2 mm 1.6 MeV/c 4.9 mm Sensitivity on CPT violation parameters on K 0 interference (αβγ) KLOE measurement (σ Δt = τ s ) KLOE-2 prevision (σ Δt = 0.25 τ s ) Factor of 10 improvement of present error feasible with 20 fb -1 (100 fb -1 needed witout IT)

The Inner Tracker 10/01/2016 Villa Olmo, Como D. Domenici - LNF5 IT to be inserted inside KLOE Inner radius 127 mm (20 τ s ) to preserve K L -K s interference region Outer radius 215 mm to safely install inside the DC IT to be inserted inside KLOE Inner radius 127 mm (20 τ s ) to preserve K L -K s interference region Outer radius 215 mm to safely install inside the DC

Inner Tracker Numbers 10/01/2016 Villa Olmo, Como D. Domenici - LNF6 5 independent tracking layers σ rφ = 200 µm and σ Z = 500 µm spatial resolutions with XV strips-pads readout 700 mm active length 1.5% X 0 total radiation length in the active region with Carbon Fiber supports Realized with fully Cylindrical-GEM detectors

The Cylindrical-GEM 10/01/2016 Villa Olmo, Como D. Domenici - LNF7 Conversion & Drift Transfer 1 Transfer 2 Induction Cathode GEM 1 GEM 2 GEM 3 Anode Read-out 3 mm 2 mm Gas Electron Multiplier (F. Sauli, CERN, 1997) Thin (50 μm) metal coated kapton foil, perforated by a high density of holes (70 μm diameter, 140 μm pitch) With 400 V between the two copper sides, a 100 kV/cm electric field is produced into the holes acting as multiplication channels for electrons produced in the gas by a ionizing particle Triple-GEM 3 mm 2 mm Cathode GEM 1 GEM 2 GEM 3 Anode Read-out Cylindrical Triple-GEM C-GEM Prototype 150 mm radius (Layer 1) x 352 mm active length 1538 strips with 650 µm pitch only along Z C-GEM Prototype 150 mm radius (Layer 1) x 352 mm active length 1538 strips with 650 µm pitch only along Z

Manufacturing the Prototype 10/01/2016 Villa Olmo, Como D. Domenici - LNF mm 960 mm Full sensitive Ultra-light detector Full sensitive Ultra-light detector Large GEM foil Vacuum bag Cylindrical GEM Cylindrical cathode

The GASTONE ASIC 10/01/2016 Villa Olmo, Como D. Domenici - LNF9 Dedicated FEE chip for the KLOE-2 Inner Tracker Low power consumption and high integration requirements 4 different blocks: charge sensitive preamplifier shaper leading-edge discriminator (with programmable thr.) monostable to stretch the digital signal for trigger Sensitivity (pF)20 mV/fC Z IN 400 Ω (low frequency) C DET 1 – 50 pF Peaking time90 – 200 ns (1 -50 pF) Noise (erms)974 e e - /pF Baseline restoreryes* Channels/chip64* ReadoutLVDS/Serial Power consum.≈ 0.6 mA/ch GASTONE board ver.1

C-GEM Prototype Performance 10/01/2016 Villa Olmo, Como D. Domenici - LNF10 Performance measured at PS testbeam with GASTONE digital Readout Electronics and external Drift Tubes Tracking System Spatial Resolution  (GEM) =  (250µm) 2 – (140µm) 2  200µm Spatial Resolution  (GEM) =  (250µm) 2 – (140µm) 2  200µm Efficiency ε = 99.6%

XV Strips-Pads Readout 10/01/2016 Villa Olmo, Como D. Domenici - LNF11 X pitch 650 µm V pitch 650 µm 1000 µm 40° Peculiar XV readout designed for the cylindrical geometry X Strips for rφ coordinate V Strips at 40° formed by Pads connected by internal vias Crossing of X and V gives Z coordinate Readout extensively studied in Magnetic Field in a TB at SPS

Simulation of Magnetic Field Effect 10/01/2016 Villa Olmo, Como D. Domenici - LNF12 Ar/CO 2 =70/30 B=0.5 T Lorentz angle α L = 9° 700 μm Electron avalanche in a Triple-GEM (3/2/2/1 mm) with 0.5 T field. The result is both a displacement (Lorentz angle) and a spread of the charge 8 mm Dedicated 10x10 cm 2 planar chambers built to study the readout

Test Beam at SPS with Goliath 10/01/2016 Villa Olmo, Como D. Domenici - LNF13 Test Beam Parameters Gas: Ar-CO GEM Gain: 2x10 4 FEE: 22 GASTONE boards Trigger: 6 scintillators with SiPM SPS H4 beam π GeV/c SPS H4 beam π GeV/c beam GOLIATH Dipole (up to 1.5 T) 5 planar GEMs

Magnetic Field Measurements 10/01/2016 Villa Olmo, Como D. Domenici - LNF14 1: Displacement of the charge 2: Spread of the charge KLOE field Since we have a digital readout the spread of the charge also affects the efficiency, which can be recovered increasing the gain B = 0 value

Large GEM Prototype 10/01/2016 Villa Olmo, Como D. Domenici - LNF15 1.5x2.5 cm 2 pad readout PCB 70x30 cm 2 Triple-GEM planar prototype for quality and uniformity test Cathode PCB GEM3 GEM2 GEM1

Large GEM Prototype 10/01/2016 Villa Olmo, Como D. Domenici - LNF16 A very large tensioning tool has been designed. The frame gluing will be performed by using the “vacuum bag” technique, tested in the construction of the CGEM With the usual 1 kg/cm, finite element simulation (ANSYS) indicates a maximum gravitational+electrostatic sag of the order of 20 μm Meters Load Cells Jaws

Detector Parts 10/01/2016 Villa Olmo, Como D. Domenici - LNF17 FR4 support for FEE QCAL Kapton readout circuit with connectors Gastone Boards and HV connectors Carbon-fiber support for readout circuit Gas in/out

Conclusions 10/01/2016 Villa Olmo, Como D. Domenici - LNF18 The KLOE experiment has been approved for a new run starting at end-2009 In 2011 a new Inner tracker will be inserted for a fine vertex reconstruction The IT is realized with the innovative technique of fully Cylindrical GEM detectors A (almost) full-size prototype has been built and successfully tested under different conditions (X-rays, Cosmic-rays, Beam-test) The peculiar XV readout has been tested in Magnetic Field with dedicated 10x10 cm 2 chambers A large (70x30 cm 2 ) planar chamber is under construction to test the uniformity over a large area The design of the final detector and the integration with the beam-pipe and the calorimeters has started