ATLAS Tile Hadron Calorimeter at UIUC Dave Petersen, North Park University Working under HEPG Prof. Steve Errede

What, Who and Where? A Toroidal Large Hadron Collider Apparatus (ATLAS) Detector Over 30 countries involved, from Armenia to the United States (over 30 U.S. institutions are participating) To be built at CERN, near Geneva, Switzerland

What is the LHC? A proton will be colliding with another proton Will achieve energy of 14 TeV, most energetic collider in the world

ATLAS: A Five Story Detector Red line is the beam pipe Pink is the tracking detector Gray is the Solenoid Magnet Yellow is the Electromagnetic Calorimeter Green is the Hadron Calorimeter Gray tubes are muon torodial magnet Blue is the muon detector

What is UIUC doing for ATLAS? UIUC is one of 5 institutions working on the Scintillating Tile Hadron Calorimeter –Produce ~200 full-size Submodules –Test ~3,000 Photomultiplier Tubes

What is a Module? 64 Full Modules required for TileCal Each Module is composed of 8 full-size submodules, one half-size and one quarter- size.

How does the TileCal work? Steel absorbers separated by tiles of scintillating plastic When the Hadronic shower, hits the scintillating tiles, they emit light in an amount proportional to the incident energy Fiberoptics connected to the tiles carry the light to PMTs

Production of Submodules UIUC wants to finish production by May of 2002 Currently have 49 complete Looking to improve efficiency of operations-one of the biggest problems is the cleaning of the plates that has to be done by hand Over 10 miles of steel required for 192 submodules

Quality Steel from the Czechs Notice the grease on these plates Every single plate must be washed by hand There are 192 spacers plates and 32 master plates per submodule that must be washed

Stamped, Not Laser-Cut Spacers are.004 in. thinner than design qualifications The TileCal design calls for submodules must be within.002 in. So we place.004 in. stickers on each individual spacer before we glue

Gluing Takes a little over 2 hours to stack and glue one submodule Use glue machine which requires over 8,000 lines of code Prof. Errede desires to break the 2 hour barrier (his own version of the 4 minute mile)

Quality Control After welding, various measurements must be taken to ensure that each submodule meets the design requirements We must also check each individual slot for the tiles to make sure the tiles will fit

Analysis of Quality Control Here is a 3D graphical view of the average submodule heights broken up by points

Painting - In order to rustproof Toxic paint from the Czech Republic is used to “rustproof” the submodules Takes over 3 days to dry Excess paint must be ground off

Chaotic Paint? Here’s what the rustproof paint does to the steel after 3 days

Ready to Ship These submodules are ready to go to Argonne, where they will be assembled into a full module

Quality Control After welding, various measurements must be taken to ensure that each submodule meets the design requirements We must also check each individual slot for the tiles to make sure the tiles will fit

3 Kinds of Measurements Height Perpendicularity Bolt Holes

QC Man Claremont suggests a designated QC Man

QC Analysis Graphs up the wazoo!!

QC - Height Design Height = mm All within design tolerances

QC - Height QC Sheet

QC - 3D Model Tack Weld Final Weld Load plate causes sloping Final weld causes shrinking at the corners

QC - Perpendicularity QC Sheet

QC - Perpendicularity UIUC Submodules tend to be perpendicular at all points

QC - Bolt Holes /- 0.2 mm Design Separation for Bolt Holes from one weld bar to the other is /- 0.2 mm 110 +/-0.2 mm Design Bolt Hole Height on each weld is 110 +/-0.2 mm

QC - Bolt Holes Weld bars pulled in after final weld UIUC tends to produce submodules that have weld bars which are slightly off center - about 0.2 mm below the center of the submodule

Production Status 62 done, only 130 more to go!!

What will ATLAS show us? The measurements taken using ATLAS will hopefully help explain these theories –Higgs Particle and Field –Grand Unified Theory

Higgs Particle and Field Higgs field is almost indistinguishable from empty spaceHiggs field is almost indistinguishable from empty space All of space is filled with this field, and that by interacting with this field, particles acquire their masses.All of space is filled with this field, and that by interacting with this field, particles acquire their masses. Particles that interact strongly with the Higgs field are heavy, while those that interact weakly are light.Particles that interact strongly with the Higgs field are heavy, while those that interact weakly are light.

Grand Unified Theory Physicists hope to unify the weak, strong, and electromagnetic interactions

PMT Testing UIUC will perform test on the PMT’s that will measure –PMT Performance –PMT Rate Dependence –PMT Drift/Stability/Aging Studies UIUC will receive testing boxes shortly

Test Each PMT Twice Using LabView, UIUC will test each Hamamatsu R-7787 PMT twice, once in the Dark box and once in the Light box –Test 1 will use DC Light Test 20 PMTs per 2 days –Test 2 will use Pulsed Light Test 20 PMTs per day

What I’ve Learned Multi-national project has just as many disadvantages as advantages Lab Machinists are a rare kind of people (see next slide) Hands-on physics is for me

Thanks To Dr. Steven Errede Dave Forshier Henri Cordier And Fred Cogswell, who when left the project gave this farewell