SoLID Magnet Options (and unstudied calorimeter thoughts) Paul E. Reimer 28 January 2011 Physics Division Argonne National Laboratory

Magnets under consideration or “The usual suspects”  Babar  CLEO  ZEUS  CDF 28 January 2011 Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 2

BaBar 28 January 2011 Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 3 Superconducting coil Flux Return

BaBar 28 January 2011 Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 4  Original SoLID MC used BaBar Magnet  Baffles are designed assuming BaBar field  Probably not available –Will likely go to Italy

CLEO 28 January 2011 Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 5

ZEUS Magnet Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 6 28 January 2011 F. Corriveau, NIM A326 (1993)

ZEUS Magnet Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 7 28 January 2011 Superconducting coil Flux Return

ZEUS Magnet Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 8 28 January 2011

CDF magnet 28 January 2011 Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 9 F. Abe, NIM A271 (1998) Flux Return Superconducting coil

CDF 28 January 2011 Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 10  CDF Magnet has a slightly longer bore than BaBar (move target downstream in magnet)  Flux return not applicable to SoLID  Presently available after Tevatron run ends in October –There are some proposals at Fermilab which are considering using this magnet of the CLEO Magnet

Magnet Comparison BaBarCLEOZEUSCDF Cryostat Inner Radius 150 cm 86 cm150 cm Length345 cm350cm245cm500 cm Central Field1.49T1.5T1.8T1.47T Flux Return Iron Yes No Cool IconYes No Variation in Current density with z? Yes?? Varying current density 25% more current at ends No AvailableProbably Not????Probably 28 January 2011 Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 11

Calorimeter Thoughts Paul E. Reimer 28 January 2011 Physics Division Argonne National Laboratory

Calorimeter in Solenoid Flux Return  How to get the light from the calorimeter to a photosensitive detector? –APD’s –Light Guides out of field region –Use flux return for calorimeter 28 January 2011 Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 13 PMT in >10 G Calorimeter

Calorimeter in Solenoid Flux Return Open Questions:  What does magnetic field do the shower? –My guess is that charged particles in the EM shower will curl up causing the shower to become shorter and wider  How does magnetic field affect resolution in Energy and in space? Is this a strong function of field strength or direction?  What resolution do we need? [Pb:SciFi at ~1:1 gives 4.5%/sqrt(E)]  Is Iron dense enough?  How does the fiber affect the Magnetic flux return? –My guess is that we use and “effective” μ which is about half that of Fe. Require detailed MC; Have contacted D. Hertzog about simulations.  How do we cost this? –D Hertzog—driving cost is amount of fiber—Fe less dense than Pb thus need more fiber. 28 January 2011 Paul E. Reimer, SoLID Collaboration Mtg, Magnets Options 14 PMT in >10 G Calorimeter