1. Stephan Haensel - 6th SiLC Meeting - Torino Silicon Envelope for the Large Prototype TPC @ DESY Stephan Hänsel Institute of High Energy Physics, Vienna 6th SiLC Meeting - Torino

2. Stephan Haensel - 6th SiLC Meeting - Torino Contents Introduction Overview of the Experiment Silicon Envelope Cosmic Setup Outlook First Prototype

3. Stephan Haensel - 6th SiLC Meeting - Torino Introduction The SiLC collaboration will participate at the Large Prototype TPC (LPTPC) at the EUDET facility at DESY II. SiLC will design, build and install position sensitive detector modules around the LPTPC made of silicon microstrip sensors that can be used as telescope. The design will allow an easily exchange of the modules to enable tests of different sensor- and chip- designs. This setup will also help to verify if a silicon envelope for a future linear collider TPC is reasonable.

4. Stephan Haensel - 6th SiLC Meeting - Torino EUDET facility at DESY II a bremsstrahlung beam is generated by a carbon fibre inside the e + /e - synchrotron DORIS II the photons get converted to e + /e - -pairs with a metal plate the beam is selected in sign and spread out into an horizontal fan with a dipole magnet the final beam gets cut out of this fan with a collimator typical momentum of electrons reaching beam line T24: 1 to 6 GeV/c, spread ~ 5%, divergence ~ 2mrad

5. Stephan Haensel - 6th SiLC Meeting - Torino Top view of the Setup (Drawing from: http://www-flc.desy.de/tpc/) ID of magnet inner bore 850 mm measured minimum 846 mm SiLC detectors2 x 35 mm clearance inside of SiLC 780 mm extra clearance 2 x 5 mm OD of field cage 770 mm field cage wall2 x 25 mm ID of field cage 720 mm radial dimensions:

6. Stephan Haensel - 6th SiLC Meeting - Torino A PCMAG coil built by KEK was already installed in the DESY test beam are T24 in December 2006 and in July its field was measured. Magnet and TPC the TPC field cage design was made on the basis of smaller prototypes the end-plate will contain a number of ’windows’ into which pad panels will fit  different readout systems (GEMs, Micromegas, …) will be tested  two thin layers of glass-fibre reinforced plastic, honeycomb Nomex as spacer (Pics from K.Dehmelt) B max ~ 1,25 T

7. Stephan Haensel - 6th SiLC Meeting - Torino Silicon Envelope four silicon modules will be installed: -two in front and two behind the TPC, with respect to the e - -beam  two independent support structures are needed -on each side:  one horizontal module consisting of two daisy-chained sensors  and one vertical module consisting of one sensor movable support system is needed because it must be possible to scan the TPC -the TPC and the magnet will move relative to the beam TPCMagnet Beam Rails Module - the sensors have to stay inside the beam line  sensors must be movable orthogonal to the beam and along a curved rail  this movement must be coupled with the movement of the TPC and the magnet  in addition the two sides have to move independently from each other

8. Stephan Haensel - 6th SiLC Meeting - Torino 2D Layout Magnet Beam 1 Sensor Module 2 Sensor Module radial dimensions: magnet inner bore425 mm measured minimum423 mm SiLC detectors 35 mm on radius clearance inside SiLC390 mm  it is possible to build an envelope which only needs 25 mm on radius  would give an essential 5 mm clearance to surroundings sliding carriage TPC Sensor Readout based on APV25 (CMS-hybrids) IEKP Karlsruhe will provide the readout system it is foreseen to replace parts of the CMS readout system with newly developed electronics containing the SiLC readout chip in the future

9. Stephan Haensel - 6th SiLC Meeting - Torino Modules Sensors single sided AC coupled sensors from Hamamatsu Japan size: 91.5 x 91.5 mm, thickness: 320 μm 1792 readout strips with a strip pitch of 50 μm first setup: only 768 channels can be read out  the readout sensitive area is reduced to 38,4 x 38,4 mm² (only the intersecting readout area of the two modules on top of each other is interesting) sensor details -> Talk of T. Bergauer: “Silicon Strip Sensor R&D and results from HPK sensor measurements”

10. Stephan Haensel - 6th SiLC Meeting - Torino Modules Front-End Hybrids including Pitch Adapter Start up: hybrids leftover from the CMS Tracker End Cap module production will be used  already assembled and bonded Later on: replacement with newly developed FE chips

11. Stephan Haensel - 6th SiLC Meeting - Torino Modules Intermediate Pitch Adapter to connect a pitch of 143  m (CMS-R2) with a pitch of 50  m (new HPK) 2 different PA ordered: ILFA GmbH  4-layer printed circuit board (PCB)  two layers of Cu-lines with 100 μm pitch glued staggered and shifted on top of each other Helsinki Institute of Physics (HIP), Academy of Finland  Aluminium on quartz

12. Stephan Haensel - 6th SiLC Meeting - Torino Modules Isoval ® 11 Frame Isoval ® 11 is a composite of resin epoxy reinforced with a woven fibreglass mat high rigidity low mass insulator easy to mechanically process modules are not glued but get clipped to the frame with 3 mm thick Isoval ® 11 pads which get screwed to the frame -> easy exchange of modules to enable tests of different sensors and FE chips

13. Stephan Haensel - 6th SiLC Meeting - Torino Modules HV Kapton Foil deliver the HV bias voltage to the sensor backplane isolate the sensor backplane from the carbon fibre profiles modified leftovers of the CMS sensor recuperation campaign are used  they contain already RC circuits to stabilize the HV line Wire Bonds standardised ultrasonic wire bonding with a Delvotec 6400 automatic bonding machine aluminium wires: 25 μm diameter including 1% silicon

14. Stephan Haensel - 6th SiLC Meeting - Torino Modules Carbon Fibre Beams backbone of each module consists of two carbon fibre T-beams for such a low quantity it’s not affordable to order perfect profiles from a company  SECAR Technologie GmbH provided rectangular beams  not maximised in terms of radiation length and rigidity  two such beams get glued together with a thin film of araldite glue to form a T-beam which is rigid enough to support the sensors, pitch adapter and the front-end hybrid

15. Stephan Haensel - 6th SiLC Meeting - Torino Moveable Support System two aluminium sliding carriage for the silicon modules get build by IEKP Karlsruhe –movement of the two diagonally arranged frames, containing the silicon modules, independently in both, phi and in z direction phi-direction: curved rails mounted at the outside of the magnet and at the beginning of the magnets bottleneck z-direction: the sledges move along two round rods via a threaded rod Rails

16. Stephan Haensel - 6th SiLC Meeting - Torino Cosmic Run I beam shutdown at DESY in the first half of 2008  the test beam will not be available before August 2008 in the meantime: perform first tests with cosmics TPC cosmic setup is expected to be finished in Feb. 08 we will participate at the Cosmic Run  gain experience in operating the readout systems of the silicon modules and the TPC together  join the experiment right from the beginning (Drawing from K.Dehmelt)

17. Stephan Haensel - 6th SiLC Meeting - Torino Cosmic Run II design of the silicon envelope has to be changed:  modules will be installed at the top and bottom of the TPC which interferes with the support plates of the TPC  sliding carriage for the cosmic run silicon envelope only needs to be moveable in z-direction  no changes are needed on module level very rough estimation expects only about 20 Muon coincidences per day in the intersecting readout areas of all four silicon sensors  readout of 768 sensor strips lead to a small sensitive area of only 38,4 mm width per module

18. Stephan Haensel - 6th SiLC Meeting - Torino Outlook first prototype (broken CMS-R2 hybrids, dummy sensors and dummy intermediate pitch adapter – next slide) was already shipped to IEKP Karlsruhe -> they will soon build the sliding carriage the needed space for the envelope has to be fixed in agreement with the TPC support structures  quite narrow in cosmic setup  no interference in final setup it has to be defined were the envelope support can be fixed  most probable at the outside of the magnet and the beginning of the magnets bottleneck via curved rails the intermediate PA are ordered but not delivered and tested HPK sensors already passed QA tests APV readout system details will be determined in Jan. 2008  Everything looks promising towards a start of the cosmic run in the first quarter of 2008!  The cosmic run is a great possibility to make first experiences with the modules, the readout system and a simplified module support system.

19. Stephan Haensel - 6th SiLC Meeting - Torino First Prototype broken CMS-R2 hybrids, dummy sensors and dummy intermediate pitch adapter, Stephan Haensel - 6th SiLC Meeting - Torino

20. BACKUP Slides

21. Stephan Haensel - 6th SiLC Meeting - Torino 3D Layout TPC Magnet Beam Rails 1 Sensor Module 3D Layout 2 Sensor Module Stephan Haensel - 6th SiLC Meeting - Torino

22. HPK Sensors (6 needed for this setup) Will be delivered in the end of September. - single-sided AC coupled SSD - Sensor size: 91,5 x 91,5 mm² (± 0,04 mm) - Wafer thickness: approx. 320 μm - Resistivity: such that depletion voltage: 50 V < V depl < 100 Volt - Leakage current: < 10 μA per sensor - Biasing scheme: poly-Silicon Resistor with 20 MW (± 5 MW) - Number of strips: 1792 (= 14 x 128) - Strip pitch: 50 μm pitch, no intermediate strips - Strip width: 12.5 μm - Dielectric Structure: Oxide (SiO2) + Nitride (Si3N4) between p+ and aluminium strips. (Thicknesses like for CMS) - 2 bond pads on each side of the strip (CMS size) - 1 probe pad on each side of the strip (contact to p+) Wafer Layout 91,5 x 91,5 mm