S800 Documentation

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
====== Introduction ======
The S800 ((D. Bazin, J.A. Caggiano, B.M. Sherrill, J. Yurkon, and A. Zeller, Nuclear Instruments and Methods in Physics Research B 204, 629 (2003) )) is a superconducting spectrograph used for reaction studies with high-energy radioactive beams produced at the [[http://www.nscl.msu.edu|NSCL Coupled-Cyclotron Facility (CCF)]] and the [[http://www.nscl.msu.edu/exp/devices#a1900|A1900 Separator]] ((D.J. Morrissey, B.M. Sherrill, M. Steiner, A. Stolz, and I. Wiedenhoever, Nuclear Instruments and Methods in Physics Research B 204, 90 (2003) ). It was designed for high-precision measurements of scattering angles (ΔΘ=2 msr) and momentum (p/Δp=2×10<sup>4</sup>), and large momentum and solid-angle acceptances (ΔΩ=20 msr, Δp/p=6%). The S800 layout shown in the next figure depicts the two parts of the S800: the analysis line and the spectrograph. 

{{:wiki:s800_layout.png|Layout of the S800}}

=== Analysis Line ===

The analysis line extends from the object position to the target station, with a total length of 22 m. It includes four 22.5° dipoles, five quadrupole triplets, and two vertically steering magnets, assembled in two segments with configurations QQQ-H-DD-QQQ (segment 6) and QQQ-DD-H-QQQ-QQQ (segment 7) symmetrically oriented around an intermediate image plane. The maximum rigidity is 5 Tm, although it depends on the tune of the quadrupoles. The acceptances of the analysis line depends on the optical mode.


=== Spectrograph ===
The spectrograph consist of two quadrupoles, a sextupole and two big dipoles assembled in a QQ-S-DD configuration (segment 8) that spans vertically from the target station to the focal plane, with a total length of 18 m. The figures of merit of the spectrograph are summarized in the next table and figure below. Achieving the nominal angle and momentum resolution require the control of different conditions such as object size (less than 0.5 mm), target thickness, uncertainty of the incident angle on the target, intensity, and whether or not the incoming beam needs to be tracked. 


^ Momentum Resolution (p/Δp)      | 2×10<sup>4</sup> |    
^ Momentum Acceptance             | 5.8%             | 
^ Angle Resolution                | 2 msr            |
^ Solid Angle Acceptance          | 7º×10º or 20 msr |
^ Momentum Dispersion (x/δ)       | 9.5 cm/%         |   
^ Angle Dispersion (y/b)          | 0.9 mm/mrad      |   
^ Magnification(x/x)              | 0.74             | 
^ Focal Plane Size (x × y)        | 55 cm ×15 cm     | 
^ Maximum Rigidity                | 4 Tm             | 
^ Detector Position Resolution (x)| 0.3 mm           |
^ Detector Position Resolution (y)| 0.3 mm           |
^ Weight                          | 250 tons         |
^ Length Analysis Line            | 22 m             |
^ Length Spectrograph             | 18 m             |




{{:wiki:Resolutions.png?700|Energy and Angle resolutions of S800}}
S800 Documentation

User Tools

Site Tools

Page Tools
