Tracking News in ILD Paul Colas CEA Saclay

Tracking News in ILD Paul Colas, CEA Saclay Magnet Vertex detector FTD and ETD TPC Software (without forgetting, in fine, the tracking calorimeter and muon system)

Introduction LOI and DBD Recent developments and optimization in progress We now have a realistic (though unofficial) estimate of the schedule (S. Komamiya, Lepton-photon 2015) : Start 2016? 2018? 2033 ? 04/11/2015 Tracking news in ILD 2

t 0 = Ground Breaking After Y. Sugimotos 2033? The yoke and the solenoid have to be assembled on surface site very early (start Y 3) The remaining of the tracker is for end of Y 8 04/11/2015 Tracking news in ILD 3

Magnet Curves tracks, allowing p measmnt : p (Ge. V) = 0. 3 B (T) R (m) dp/p² ~ s (sagitta) / Bl² A Magnetic field necessary to limit the pair background in the detector. The mask provides a q cut The magnet a p. T cut Takashi Maruyama 04/11/2015 Tracking news in ILD 4

ILD SUPERCONDUCTING MAGNET Note LC-DET 2012 -081 (June 2013) F. Kircher et al. 3 parts - SC solenoid - SC anti DID (Detector Integrated Dipole) - Yoke Main parameters SC solenoid - nominal field: 3. 5 T - design field: 4 T - warm bore: 3. 44 m - length: 7. 35 m At 4 T - max. field on conductor: 4. 6 T - current: 22. 4 k. A - stored energy: 2. 3 GJ - density of stored energy: 13 k. J/kg Anti –DID (B. Parker) - max. dipole field: 0. 035 T - inner radius: 4. 16 m - total length: 6. 8 m

Anti DID Recent evolution : - Quadrupole re-design might allow reducing the crossing angle (14 10 -12 mrad) (B. Parker at Oshu, 9/2014) - Anti-DID might be around the beam pipe - Disaligning the two halfs of the solenoid might play the role of the anti-DID. 04/11/2015 Tracking news in ILD 6

• Costing (F. Kircher, H. Videau, C. Clerc): 131 k. ILCU • Re-inforced-conductor development (CERN): in progress (B. Curé, CERN) • Field measurement to be planified 04/11/2015 Tracking news in ILD 7

Vertex detector General Layout (DBD) 3 pairs of pixel layers CMOS option 04/11/2015 Tracking news in ILD 8

Vertex detector technologies 3 technologies actively studied for ILD : FPCCD, DEPFET and CPS • Fine Pixel CCD : 6 x 6 µm² pixels slabs under study. Tolerance to n should be OK. Double-sided prototyping stated • DEPFET : R&D driven by BELLE-2 PXD (2018) • 1 st complete ladder functionnal 50 x 55/85 µm² • Pilot production of sensors gives the yield • Power cycling validated, but without B field • Micro-channel cooling under development • CMOS Pixel Sensors (Monolithic Active Pixels) • Driven by ALICE ITS and CBM-MVD (>2020) • 2 year experience of phys. Run at STAR-PXL • Fast. Effic. , resol. , noise measured on 6 chips • 2 -sided ILD ladder concept with 1 -2 µs time stamping achievable 04/11/2015 Tracking news in ILD 9

CMOS pixels effic, resolution, noise (vs threshold/noise) M. Winter 04/11/2015 Tracking news in ILD 10

Micro-Channel Cooling on ultra-thin Silicon sensors 6 W H 2 O Micro-channel pattern in handle wafer Standard etching procedure Low cost mono-phase fluid: H 2 O Peek tube 3 D-printed adaptor Low volumetric flow (~1 l/h) and low pressure (< 1 bar) are enough to dissipate the heat in the front end Good agreement with the FE simulation inside an error area of 10% Thermal Figure of Merit (TFM) of ~ 1 K·cm 2/W See talk in Vertex/Tracking session on Tuesday Advanced vertex detector cooling concepts: from air flow to micro-channel cooling M. A. Villarejo, I. Garcia (IFIC Valencia)

Vertex detector technologies TECHNOLOGY + - FINE PIXELS CCD (Tokyo) High granularity → precision, bkg rejection Read once by train : risk of saturation at high lumi or high beam bkg DEPFETS (Germany, Spain) High level of integration → material budget BELLE 2 user community Difficult trade-off between speed and spatial resol. Non-industrial technology Extension to large area (BELLE 2 x 20) Industrial technology (low cost, high evolution potential) STAR and ALICE/ITS experience Best speed/resol trade-off Techno evolution not controlled, delicate design Behaviour in high B field to be assessed (Lorentz forces) CMOS PIXELS (Strasbourg) 04/11/2015 Tracking news in ILD 12

Silicon Tracker To extend the TPC in the low-angle region and to provide a precise point at large radius on the track, preferably with time stamp. 04/11/2015 Tracking news in ILD 13

SIT, SET, ETD Layout (Si Int/Ext Tracker) 165 309 04/11/2015 371 645 Tracking news in ILD 14

FTD Layout (Forward Tracking Disks) The ALICE ITS might be a model for pixellised disks 04/11/2015 Tracking news in ILD 15

R&D on microstrips: ILGAD • • • RD 50 Sensors material dominant contribution to the material budget. Internal signal amplification in the sensor allows for thinner sensor preserving the SNR. Developing strip-like Low Gain Avalanche Detectors (reach-trough avalanche photodiode with n++ / p+/p-/p+ structure) with typical signal gain < 20 with reduced excess noise. Amplification observed in pad and strip like LGAD with segmented amplification region and electron readout To cope with spacial non-uniformities in the amplification: new prototypes with non-segmented amplification region Inverted-LGAD (with hole readout) Manufacturing run @ CNM ongoing. PAD layout Electron readout 04/11/2015 Tracking news in ILD See talk by I. Vila at Wednesday afternoon tracking session 16

RD on FE Readout ASIC and pulsed power One channel analog front-end (AMS 180 nm) to be submitted in January 2016 Radiation tolerance assessment of supercapacitors Successfully tested up to 2. 3 MRad Bias generators 04/11/2015 Slow control Tracking news in ILD 17

TPC All R&D in LCTPC world-wide collaboration www. lctpc. org 04/11/2015 Tracking news in ILD 18

EUDET TEST FACILITY AT DESY PCMAG: B < 1. 2 T, bore diameter: 85 cm Electron test beam: E = 1 - 6 Ge. V moving support structure Beam and cosmic triggers LP Field Cage Parameter: length = 61 cm inner diameter = 72 cm drift field: E ≈ 350 V/cm (25 k. V total) made of composite materials: 1. 24 % X 0. Modular End Plate in Al 7 module windows → size ≈ 22 × 17 cm 2. DESY 04/11/2015 Tracking news in ILD 19

TPC 2 x 2. 3 m length 3. 6 m diameter Self-supporting field cage Structure experienced on the Large Prototype 04/11/2015 Tracking news in ILD 20

TPC endplate possible layouts One can have 8 ‘wheels’ of module with the size of the Large Prototype, or less wheels with larger modules Four wheels, 84 modules x 2 Three wheels, 55 modules x 2 Advantage of large modules : fewer different kinds of modules to be produced, alignment easier, less cracks. However size is limited by HV stability 04/11/2015 Tracking news in ILD 21

TPC mechanics New ‘lightweight’ endplate for the Large Prototype (Cornel) to be tested soon Deflexion O(150 µm) @ 3 mbar 04/11/2015 Mechanical calculations to be re-started: - hanging model - Deformations under weight and pressure Tracking news in ILD 22

Evaluation of track distortions due to space charge effects of positive ions : design and implementation of a program to do analytic evaluation using Green’s function can be seriesexpanded in terms of modified Bessel functions! D. Arai and K. Fujii 4. Ion Disk Effect

Effects of Positive Ions and Ion Gating at ILC Solved the Poisson equation for the simulated ion density distribution with proper boundary conditions and then estimated the distortion of drift electron trajectory by the Langevin equation (D. Arai and KF) Primary Ions OK Secondary Ion disk Not OK For the secondary ions from the amplification, we need an ion gate device for the ion feed back ratio of >10 -3 (measured both for the triple GEM and Micromegas) at the gas gain of 1, 000. wire gate The current options of the ion gate are limited: The traditional wire gate is expected to work, but introduces mechanical complications to the MPGD modules. We also need to check Ex. B effect. Thin GEM gate offers the electron transmission of only 50%@ 1 T → 30% loss in the point resolution (Japanese LC TPC group). Try a larger geometric aperture with new fabrication method? K. Fujii @ FKPPL/TYL 2013, June, 2013 GEM gate New way? 24

TPC Large prototype Tests at DESY Asian double GEMs and German GEMs Micromegas March 2015 04/11/2015 Tracking news in ILD 25

TPC TESTS • Target resolution achieved by all MPGD technologies • Distortions rather under control so far, but need more studies • A new ceramic frame under study for the DESY 3 -GEM. • A new resistive material selected for charge spreading (Diamond-like carbon) • 2 P CO 2 cooling tested and electronic integration carried out for the 7 -module Micromegas option. • Electronics at reach, but too early to start design. Simulations, instead, are necessary to determine the parameters and optimize cost and power consumption. Also, association with other subdetectors has to be studied. (train-based reconstruction) 04/11/2015 Tracking news in ILD 26

Grid. Pix progress Wafer-based post-processing to add a protection layer and a mesh on pillars on top of the chips (107 chips at a time) March 2015, there was a successful test with 3 modules (96 chip each) partially equipped : 160 chips! This shows that this technique is applicable to large areas This opens the way for ultimate d. E/dx resolution 04/11/2015 Tracking news in ILD 27

Software Kal. Test Versatile Kalman filter : various measurement surfaces Segment-wise helical track model : for non-uniform B-field (Bo Li, K. Fujii) Planar 1 -dim. meas. surface（Si Strip） Turbine blade shape meas. surface（Fwd. Si） Conical surface （Beam Pipe） Planar 2 -dim. meas surface（VTX pixel） Cylindrical meas surface （TPC） 04/11/2015 Tracking news in ILD 28

Abstract Track Reconstruction Framework (i. Marlin. Track/i. Marlin. Trk. System) : Finished i. Marlin. Track & i. Marlin. Trk. System for ILD Its application to ILD simulations as demonstrated in physics studies for DBD : Finished Collaboration with S. Aplin and F. Gaede

Software Talks and Papers Talks: 1. Steve Aplin, “ILD Tracking”, LCWS 2011, Granada, 2011 -9 -28. 2. Bo Li, “Marlin. TPC track reconstruction for a full modular end plate”, LCTPC Collaboration Meeting 2012, DESY, 2012 -3 -26. 3. Keisuke Fujii, “Positive Ion Effects”, LCTPC Collaboration Meeting 2012, DESY, 2012 -3 -26. 4. Frank Gaede, Steve Aplin, “New C++ Tracking in i. LCSoft”, KILC 2012, Daegu, 2012 -4 -25. Frank Gaede, Steve Aplin, Robin Glattauer, “The New C++ Tracking Code in i. LCSoft”, LCWS 2012, Arlington, 2012 -10 -25. 6. Bo Li, Keisuke Fujii, “Track fitting in non-uniform magnetic field with a segment-wise helical track model”, LCTPC Collaboration Meeting 2013, DESY, 2013 -6 -1. 7. Bo Li, Keisuke Fujii, Yuanning Gao, “Track fitting in non-uniform magnetic field with segmentwise helical track model”, LCWS 2013, Tokyo, Japan, 2013 -11 -13. Paper: 1. Bo Li, Keisuke Fujii, Yuanning Gao, “Kalman-filter-based track fitting in non-uniform magnetic field with segment-wise helical track model”, Computer Physics Communications 185 (2014) 754– 761.

Summary and conclusions The magnet is a critical issue : it has to be fabricated first, and is is rather expensive and complicate. The rest of the tracker is in rather good shape. There is no rush to finalize electronics and cooling, the design can benefit from more R&D. Despite limited (or fragmented) funding and uncertainties on the future, engineered R&D continues, to be ready for a TDR when necessary. Still many questions are open, and there is a strong need for simulation. A train-based reconstruction should be started. Thanks to J. Kaminski, K. Fujii, M. Winter, A. Ruiz, I. Vila, M. Vos, … and AIDA 04/11/2015 Tracking news in ILD 31