S800 Documentation

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modes_of_operation [2016/01/19 12:31]
pereira [Focus Mode] 		modes_of_operation [2016/01/19 12:35]
pereira [Dispersion-matching Mode]
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-{{:wiki:focused.png?550|Mask pattern measure in CRDC2 during a reaction setting.}}+{{:wiki:focused.png?750|Ion optics diagram for S800 in focus mode.}}
 ===== Dispersion-matching Mode ===== ===== Dispersion-matching Mode =====
-In the dispersion-matching mode the whole system ([[Introduction#Analysis Line|analysis line]] + [[Introduction#Spectrograph|spectrograph]])  is achromatic in the focal plane (see [[Fig. xxx]]). The analysis line has a 2D focus (in the dispersive //x// and non-dispersive //y// directions ) in the target point and has a high dispersion of about 11 cm/%, limiting the momentum acceptance to ±0.5%. The intermediate image plane has also a 2D focus and a dispersion of 1.5 cm/%. This mode provides the highest possible energy resolution (1 part in 5000 for a 1-mm wide beam spot), since it does not require momentum tracking. +In the dispersion-matching mode the whole system ([[Introduction#Analysis Line|analysis line]] + [[Introduction#Spectrograph|spectrograph]])  is achromatic in the focal plane (see figure below). The analysis line has a 2D focus (in the dispersive //x// and non-dispersive //y// directions ) in the target point and has a high dispersion of about 11 cm/%, limiting the momentum acceptance to ±0.5%. The intermediate image plane has also a 2D focus and a dispersion of 1.5 cm/%. This mode provides the highest possible energy resolution (1 part in 5000 for a 1-mm wide beam spot), since it does not require momentum tracking. 
 Please, be aware that in this configuration, two of the quadrupoles before and after the intermediate image plane (I210TB and 217TB) are strongly focusing, thus requiring unusually higher currents than for a setting in focus mode running at the same rigidity. This may represent a restriction to consider when planning an experiment at high magnetic rigidities (e.g. using a <sup>3</sup>H secondary beam). Please, be aware that in this configuration, two of the quadrupoles before and after the intermediate image plane (I210TB and 217TB) are strongly focusing, thus requiring unusually higher currents than for a setting in focus mode running at the same rigidity. This may represent a restriction to consider when planning an experiment at high magnetic rigidities (e.g. using a <sup>3</sup>H secondary beam).
  
 +{{:wiki:matched60x40.png?750|Ion optics diagram for S800 in dispersion-matching mode.}}
 ===== Monochromatic Mode ===== ===== Monochromatic Mode =====
 __The monochromatic mode is still in development stage__. The motivation is the production of low-energy (5-10 MeV) secondary beams from a high-energy fragmentation beam. The implementation of this mode requires the use of a mono-energetic wedged installed in the intermediate image station. The wedge profile must be built  on a case-by-case basis, considering the specific energy and nuclei in the experiment.  __The monochromatic mode is still in development stage__. The motivation is the production of low-energy (5-10 MeV) secondary beams from a high-energy fragmentation beam. The implementation of this mode requires the use of a mono-energetic wedged installed in the intermediate image station. The wedge profile must be built  on a case-by-case basis, considering the specific energy and nuclei in the experiment. 
  
modes_of_operation.txt · Last modified: 2017/03/03 20:41 by pereira

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