1. OSU meeting, 04/24/2003 Richard Kass1 Limited Streamer Tube Project Overview Richard Kass Ohio State University Introduction (why, who, what….) The big picture (will leave detailed discussions for tomorrow) tubes installation electronics Ongoing prototype tube work Summary

2. OSU meeting, 04/24/2003 Richard Kass2 Dec. 2002

3. OSU meeting, 04/24/2003 Richard Kass3 Key LST Project Goals Good efficiency to detect muons and K L ’s must fit in the present barrel structure thickness of detector limited to “22mm” Long Term Reliability last until the end of BaBar Installable during summer shutdowns 1/3 in 2004 2/3 in 2005

4. OSU meeting, 04/24/2003 Richard Kass4 The Initial LST Team * M. Andreotti, D. Bettoni, R. Calabrese, V. Carassiti, A. Cotta Ramusino, G. Cibinetto, E. Luppi, M. Negrini, L. Piemontese INFN Ferrara T. Allmendinger, K.K. Gan, K.Honscheid, H. Kagan, R. Kass, A. Rahimi, C. Rush, Q. Wong, M. Zoeller Ohio State University C. Fanin, M. Morandin, M. Posocco, M. Rotondo, R. Stroili, C. Voci INFN Padova M. Loveterre, E Robutti, S Passaggio, S Capra, C Patrignani, S Minutoli INFN Genova G Piredda, C. Voena, F. Ferroni, S. Morganti, L. Cavoto INFN Roma R. Baldini, A. Calcaterra, P. Patteri, A Zallo, U. Denni, INFN Frascati L. Cavoto, R. Fernholz, C. Lu, J. Olsen, W. Sands, A.J.S. Smith Princeton University * As of Feb BaBar Meeting We welcome new groups!

5. OSU meeting, 04/24/2003 Richard Kass5 LST Building Blocks Tubes: The basic building block Each tube is ~2  10  375 cm A tube forms the gas volume (IsoB/Ar/CO 2 ) Anode wires are ganged together in a tube 16 wires/tube double layer small cells 8 wires/tube single large cell Resistive graphite coating on inner walls Do not readout anodes, use cathode strips ~2000 tubes in system Modules: Groups of tubes Tubes (e.g. 6) glued together form a module ~400 modules in system

6. OSU meeting, 04/24/2003 Richard Kass6 Propose double-layer of wires in small cells (9x8mm) Readout of x and y coordinates from outside strips Small Cell Tube Design Single layer of 9x9 mm cells limited to  ~90% by geometry  Need 2 layers of wires to obtain efficiency > 95% Questions of long term reliability of 9 x 9 cells Thickness of double layers ~23mm will use 9x9’s where gap is only 22 mm Will not readout the anode wires

7. OSU meeting, 04/24/2003 Richard Kass7 Double Layer Design

8. OSU meeting, 04/24/2003 Richard Kass8 Single-layer of wires in a large cell (15x17 mm) Readout of x and y coordinates from outside strips Large Cell Tube Design Reliability expected to be much higher for large cell less sensitive to mechanical imperfections Failure rate of MACRO tubes 0.1% in ten years ZEUS high initial mortality, 5%, then 2 % in 7 years Possibility to power HV on each or only 2 cells Will not readout the anode wires 15x17mm cells

9. OSU meeting, 04/24/2003 Richard Kass9 The LST building blocks Base Design: z-strips 38.5 mm wide 96/layer, 6912 total  -strips 42.5 mm wide 2 strips/tube 4074 total 10986 channels of electronics

10. OSU meeting, 04/24/2003 Richard Kass10 LST DETECTOR LAYOUT Exploded view of the composite detector module.  strip readout board shown

11. OSU meeting, 04/24/2003 Richard Kass11 ~ 0.9mm W G 1 2 3 4 E 2 mm 1: PET 190  m with copper lamination machined in strips of width W and separation gap G; G = 2 mm, W = 36mm for the Z strips, W = 36mm or 40mm for the  strips according to the version of LST. 2,3: PET 250  m 4: PET 50  m with solid copper lamination Composite readout strip plane

12. OSU meeting, 04/24/2003 Richard Kass12 Installation of the Z-strip plane decoupled from the modules Zstrip readout plane is installed before the modules corner pieces are removed Zstrip connectors located at the backward end of the Z plane will not block insertion of the modules from forward end of the IFR Z IFR BACKWARD IFR FORWARD signal connectors z plane fabricated from 3 boards

13. OSU meeting, 04/24/2003 Richard Kass13 Z-Strip Plane Inserted into Gap before modules THE Z-STRIP PLANE SLIDES INTO THE GAP A TOOLING FOR HOLDING AND MOVING THE FOIL IS NEEDED Installation

14. OSU meeting, 04/24/2003 Richard Kass14 Modules Are Inserted Into Gap After Z-Strip number of tubes/modules/gap varies… Installation

15. OSU meeting, 04/24/2003 Richard Kass15 An Individual Module Can Be Extracted From the Detector Unlike the Present RPC System De-Installation

16. OSU meeting, 04/24/2003 Richard Kass16 Electronics Front End Electronics (Ferrara, Genova, Ohio State ) Conceptual Design for Front End complete High Voltage (Ohio State, Padova) Conceptual design for OSU system complete Evaluating CAEN system recycle high voltage system from LVD Data acquisition system Use present RPC system

17. OSU meeting, 04/24/2003 Richard Kass17 Front End card: block diagram

18. OSU meeting, 04/24/2003 Richard Kass18 Layout of the readout crate

19. OSU meeting, 04/24/2003 Richard Kass19 First OSU HV Prototype (5 ch) 6kV Dc/Dc HV Op-Amp 15 V In 0-5 kV Out Current Monitor Protection Floating 5V Supply Current Monitor Outputs

20. OSU meeting, 04/24/2003 Richard Kass20 Tube Prototypes 1) pre-prototype double layer tubes (9x9=>9x8 mm) 2) “standard” cells: 9 x 9 mm tubes 3) “small” cells: 9x8 mm double layer tubes 4) “large” cells: 15x17 mm single layer tubes Four different types of tubes are under study baseline Very detailed studies of each tube geometry: voltage plateau mechanical stability signal quality shielding issues

21. OSU meeting, 04/24/2003 Richard Kass21 LST Prototypes First prototype (two 9x8 profiles) was built in order to test the readout scheme To do this old 9x9 profiles were machined down to 9x8 mm Readout scheme successfully tested Efficiency measured, about 96% The first double-layer prototype! ConfigurationEfficiency Both side ON96.5% 1 side ON – same side 92.8% 1 side ON – opposite side 91.2% Voltage Plateau narrower than expected  Prototypes have been opened up and examined Problem traced to inadequate Q/C, rough edges in machined profiles (actual tubes will be extruded)

22. OSU meeting, 04/24/2003 Richard Kass22 “standard” 9x9 mm tubes LST Protypes Ordered 20 standard 9x9 tubes re-establish production quality 10 with Au-coated wires 10 with Ag-coated wires Plateau measurements in progress, first results are very good silver wire similar good results for gold wire

23. OSU meeting, 04/24/2003 Richard Kass23 LST Prototypes “small” cells Prototype pre-production of 9x8 mm cells two profiles in a single cover Order for dies and all components placed Expect the tubes early May Goal: Have these tubes tested by Elba meeting

24. OSU meeting, 04/24/2003 Richard Kass24 LST Prototypes large-cell single layer prototype Dies ordered for 15 x 17 mm cell Graphite coating machine modifications built This is not standard technology for Pol.Hi.Tech Fabricate parts necessary to complete prototype designed and ordered Expect to be able to test prototypes in early June

25. OSU meeting, 04/24/2003 Richard Kass25 Pol.Hi.Tech. will assemble and test tubes Tube Construction and Assembly Tubes will be manufactured and assembled in Italy Focus on quality control Inspection of Comb Shape Profiles Inspection of graphite coating Surface resistivity monitor wire stringing proceedure Inspection of end caps Test for gas leaks HV conditioning Long Range Test and Plateau measurement Add Additional Checks as necessary

26. OSU meeting, 04/24/2003 Richard Kass26 Module Assembly Tubes will be glued together to make modules Assembly sites at Princeton and OSU Focus on quality control Inspection of Shipping Boxes Tube Resisitance and Capacitance Measurement Leak Test?? Burn in Procedure (~1 week) Signal Shape Test Plateau Curve (>300V) Tube Efficiency Scan Test with Radioactive Source Inspect  strips Module burn in test (~1 weeks) Add Additional Checks as necessary

27. OSU meeting, 04/24/2003 Richard Kass27 What Do We Have To Do? 1. Refine Cost estimate, WBS for IFC 2. Design cables and understand compatibility with RPC FEC 3. Prototyping 1. Test present prototypes 2. Visit PolHITech to discuss manufacture procedures 3. Aging of PVC 4. Double and/or single layer 5. Decide geometries to order   strip design 7. Z strip design 8. Obtain standard 9x9 with high resistivity 9. Make drawings for dies, mandrils 4. Understand finances for prototype costs 5. Order prototypes 6. Test prototypes 7. Order tubes Pre-production

28. OSU meeting, 04/24/2003 Richard Kass28 production Design set Q/A up Follow construction at Polytech Test tubes at PolHi Tech Ship to OSU and Princeton FEC design FEC design review Test FEC prototype FEC production Crates FEC testing FEC Q/A Design and fabricate Assembly Fixtures Material Handling, Equipment, and procedures Receive and test tubes at assembly sites Assemble modules Full system test in US Ship to SLAC Data Base setup What Do We Have To Do? z strip construction, QC  strip construction, QC HV System HV Distribution Monitoring, Controls (Gas System, HV, environment, etc) Simulation Monitoring electronics Cabling Gas system design Gas system fabrication Ship stuff to SLAC Receive, test, store modules at SLAC Installation fixtures Installation plan and procedure Plan for replacements, repairs Many important tasks still not covered!  Opportunities for new groups.