WP 2 activities SVD Christoph Schwanda HEPHY Vienna

WP 2 activities – SVD Christoph Schwanda (HEPHY Vienna) For the Belle II SVD group JENNIFER Consortium General Meeting September 22, 2016, QMUL, London UK

Components of the Belle II SVD VXD requirements • Fast – to operate in high background environment • Better resolution at IP – to compensate reduction of boost wrt. Belle I • Radiation hard (up to 100 k. Gy) • Self-tracking capable – to track particles down to 50 Me. V in p. T Outer CF shell Carbon fiber (CF) cone End flange End rings Ladders PXD (independent sub-detector inside SVD) Beam pipe 2

SVD ladders L 6 Ladder FWD module (Kavli IPMU) FWD Layer Ladders (spares) DSSDs / ladder 6 16 (4) 5 5 12 (3) 4 4 10 (2) 3 3 7 (2) 2 Origami +z L 5 Ladder Origami ce (HEPHY) Origami -z L 4 Ladder BWD 47 FW/BW + spares (4) BWD module (TIFR) L 3 Ladder (Melbourne) Cooling pipe FWD module (Pisa) Cooling pipe BWD module (Pisa) Cooling pipe 3

SVD silicon sensors Sensor thickness = 300 -320μm DSSD (Double-sided Si strip detector) thickness: 320 mm e sid p n-s (ot ide s he trip r si (la de r ) (sm ge) 6 all) 0 m 40 m mm ip r t s 5 m 12 m Trapezoidal sensor (Micron) Strip numbers and pitches 768 768 p-strip pitch 75μm 50… 75μm # of n-strips 512 768 512 n-strip pitch 240μm 160μm 240μm thickness: 300 mm mm # of p-strips 126 Rectangular Trapezoidal (Large) (Small) 41 mm ip str e) ide sid p-s ther (o • 3 types of DSSD sensors Sensors Rectangular sensor (HPK) trip n-side s 61 mm 4

APV 25 – front end readout ASIC APV 25 chip • Specifications – – APV 25 chips in ladder # of input channels: 128 ch. shaping time: 50 nsec radiation hardness: > 1 MGy max heat dissipation: 0. 4 W • necessity of cooling – Within acceptance thinned to 100 mm for reduction of the material budget APV 25 5

“chip on sensor” concept ORIGAMI flex (Si sensor is under the flex) Sensor under ORIGAMI (n-strips) n-strip signals p-strip signals n n APV 25 n-strip signals APV 25 Sensor from other side (p-strips) p-strip signals Flex circuit (ORIGAMI flex) is glued onto sensor n -side on an isolation foam APVs are placed directly onto the ORIGAMI flex Wire bonding with Al wires. to minimize the analog path length (capacitive noise) • Sensor strips and ORIGAMI flex are connected with Al wire-bonding (φ25 mm). 6 flip APV 25

CO 2 ladder cooling CO 2 cooling pipe in final setup (CAD) Cooling pipes attached on ladders cooling pipe Softtherm • 2 -phase (liquid and gas mixture) CO 2 cooling system APV 25 chips Softtherm 86/125 – Efficient and low mass cooling – Simple control of coolant temperature (only with pressure) – Small pressure loss in the pipe • Thin stainless tube (OD: 1. 6 mm, thickness: 0. 1 mm) used to minimize material thermal-conductive dielectric pad. 7

Distributed SVD assembly @HEPHY (Austria): • Layer-5 assembly @KEK (Japan): Ds to IPMU S S D W B / FW • FW and BW DSSD assembly TIFR (India) • Assembly sites are reviewed by the SVD QC group to guarantee compliance of the local production • All parts (quality grade, location) are tracked in a construction data base ladders to KEK @Univ. of Pisa (Italy): • Layer-6 assembly • Layer-4 assembly by TIFR yer-3 Assembled La FW/BW DSSDs to HEPHY @Kavli IPMU (Japan): Assembled Layer-5 ladders to KEK • SVD assembly • SVD installation @Univ. of Melbourne (Australia): • Layer-3 assembly 8

Ladder quality assurance • 1. Mechanical precision measurement with CMM – Control reference point possitions on DSSD sensors in 3 -dimensions • 2. I-V curve measurement I-V curve – Confirm the sensor functionality for biasing. • 3. b-source (Sr 90)/laser measurement Hit map Noise map Cluster size distribution S/N ratio distribution 9

Ladder production status • Now all the ladder assembly sites are in mass-production stage BW FW • FW/BW DSSD – BW: 100% completed – FW: 93% completed Layer-3 • Layer-3 Ladder – 5 out of 7+2 ladders (56%) completed • Layer-4 Ladder Layer-4 – 3 out of 10+2 ladders (25%) completed • Layer-5 Ladder – 4 out of 12+3 ladders (27%) completed • Layer-6 Ladder Layer-5 – 3 out of 16+4 ladders (15%) completed • Completion of the ladder production by Nov. 2017 is expected Layer-6 10

SVD assembly at KEK • SVD assembly at KEK is the final step to complete construction of SVD • Prototypes of all mount tools are available • We will finalize the tools by February 2017 Ladder mount tool CO 2 pipe attachment tool Softtherm attachment tool 11

Beam test at DESY in April 2016 SVD ladders SVD+PXD in the box Solenoid magnet PXD SVD + PXD detector setup Apr 2016 • 2 -5 Ge. V/c e- beam at DESY • Simultaneous operation of SVD layers L 3 to L 6 • SVD + PXD combined setup D insert SVD+PX into magnet e- beam Beam test setup (@ DESY T 24/1 hall) 12

Ladder Performance for Tracking (DESY results) Tracking event display SVD ladders reconstructed track • Excellent SVD performance was confirmed during the April 2016 testbeam @ DESY Residual distribution Layer-3 p-strips preliminary Layer-3 n-strips preliminary Consistent with expectation DSSD hit inefficiency (= 1 -efficiency) Layer-5 p-strips preliminary Layer-5 n-strips preliminary Single hit efficiencies above 99% 13

Summary • SVD ladder construction is now in full swing – Expect to finish by November 2017 • SVD assembly at KEK – Procedures are now being finalized – Final assembly at KEK will start in February 2017 • SVD will be ready for integration with PXD by the end of 2017 • Full BEAST phase 2 geometry has been successfully tested in DESY in April 2016 14

BACKUP 15

Ladder Anatomy (L 6 ladder) DSSDs • 2 small rectangular (L 3) • 2 -4 large rectangular (L 4 -6) • 1 trapezoidal (L 4 -6) Origami hybrid APV 25 Readout ASIC of the strips PA 0 PF 2 PF 1 Origami hybrid Flexible circuit to transmit detector signals to the ladder ends PA 1 PA 2 AIREX PB 2 Flex. PA (PA/PF/PB) Flexible circuit to transmit detector signals to the APV 25 PA 0 Flexible circuit glued on the Origami hybrid to transmit n-side detector signals to the APV 25 DSSD PB 1 Rib AIREX Thermal insulator between the DSSD and APV 25 16

Ladder production schedule End of L 3 production: Sep 2016 End of L 6 production: Nov 2017 17