Pair Spectrometer

== Pair Spectrometer v10.0 (doc) 
== Pair Spectrometer v9.3 pdf 
== Pair spectrometer proposal: Version presented to the Sept08 collaboration meeting
== Pair Spectrometer draft 9 first real Draft to Photon beam group
== Pair Spectrometer draft 7 with Jim's reordering
== Pair spectrometer draft 6 Hrachya's original version

Pair spectrometer overview

Excel file with track calculations

pair spectrometer spreadsheet

Proposed magnet BNL Type: 30D72.

(Power supplies are also available)

Drawings

==30D72 drawing d12-m-224-6-1
==30D72 assembly drawing
==30D72 top core
==30D72 bottom core
==30D72 drawing d12-m-228-5-1
==30D72 drawing d12-m-229-5-1

Pictures

water power connections
Water Power
ISO view
Pole
Pole
Both halves
top half end
coils1
coils2

GEANT Simulation

Pair Spectrometer's geometry implemented in the GEANT simulation.

The top plot corresponds to the elevation and the bottom plot corresponds to the plan views.

Energy resolution of 24 FSF (top) and 6 WSF (bottom) counters estimated with the GEANT simulation. The converter thickness corresponds to $5x10^{{-3}}X_{0}$ . The contribution from the beam spot size (~ 4 mm at the converter) to the energy resolution dominates for the high-energy bins of the WSF counters.

Photon energy spectrum measured by the pair spectrometer. The plot is obtained by requiring a coincidence between the FSF and WSF counters and contains 24 x 6 = 144 energy bins. The coincident rate corresponds to a high-luminosity run ( $10^{8}$ photons/sec in the coherent peak ) using Aluminum converter with the thickness of $5x10^{{-3}}$ radiation lengths.