BaBar:The Detector

Richard F Boyce 21 October 2003

The BaBar Flux Return at Kawasaki in Japan

A cross-section showing the BaBar sub systems: Flux Return, Solenoid,

Barrel Calorimeter, DIRC, Drift Chamber, Vertex Detector,

and the Endcap Calorimeter

e-

END D OOR FLUX RETURNPL ATE SEGMENTATION(9)20MM THK PLATES(4)30MM THK PLATES(4)50MM THK PLATES(1)100 MM THK PLATE

CABLES

L MAGNETC

FCAL

FORWARD END PLUG

Q5

FLOOR

COUNTERWEIGHT

Q4Q2

CA BL ES

DEWAR

D.C.ELECT.

DIRC

REMOVABLEHORSESHOE

C

DIRCELECT.

HORSE COLLARASSEMBLY

e

STAND-OFFBOX

+

D.C.ELECT.

SVT

STATIONAR Y WEDGE

C

Q4Q5

DIRCELECT.

CURTAIN WALL

RESISTIVE PLATECHAMBERS IN GAPS(19)PLANESIN BARREL(18)PLANESIN END DOORS

CYLINDRICAL RESISTIVEPL ATE CHAMBER

BARREL CALORIMETER

DIRC PMT SHIELD

DRIFTCHAMBERCABLES

1555

Q2

FLUXRETURN

SUPERCONDUCTING SOLENOID

CABLES

DRIFT CHAMBER

2295

CA BL ES

RPC Layer 18 is trapped behind 2 flux bars

RPC HV and gas lines are hidden behind the corner plates

The flux return barrel assembly started with the cradle

Each sextants weighed more than 50 tons and had to be split into two sections

The second section of the bottom sextant is added to the assembly

This is a picture of the section filled with RPC’s and ready for assembly

Notches were HV and gas lines are run

Side sextant being assembled

Top sextants being added

Bottom and side sextants assembled

Flux bar trapping RPC Layer 18

Notch for HV and gas lines

Arch added to stiffen the structure for earthquake loads

Instrumented Flux Return ready for the other sub systems

Earthquake isolators to limit the lateral forces

The superconducting solenoid comes out of the plane

And goes into the barrel

Next add thebarrel calorimeter

The DIRC with its water tank is added at the backward end of

the barrel

DIRC water tank which holds photomultiplier tubes

The Drift Chamber is added

Bill SandsDrift Chamber

This is the Vertex Detector and Final Focus Magnets with the cover off

About 15 feet

Top view of the Endcap Calorimeter being added at the forward end

Finished detector with platforms and services