JINA-CEE ION OPTICS SUMMER SCHOOL: JIOSS 2018

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tripleg_group [2018/09/14 00:30]
gastis 		tripleg_group [2018/09/14 09:32] (current)
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-This is the tutorial written by the 'triple G' group! We chose to study the 15O+4He radiative capture reaction using SECAR.+This is the tutorial written by the 'triple G' group! 
  
 In this tutorial, we will explain step by step how we work on the project [[https://wikihost.nscl.msu.edu/JIOSS/lib/exe/fetch.php?media=project_for_the_jina_ion_optics_for_recoil_separator_school_v4.pdf|here]] In this tutorial, we will explain step by step how we work on the project [[https://wikihost.nscl.msu.edu/JIOSS/lib/exe/fetch.php?media=project_for_the_jina_ion_optics_for_recoil_separator_school_v4.pdf|here]]
- 
  
  
 **Q3.** **Q3.**
 We use the example from the wiki [[https://wikihost.nscl.msu.edu/JIOSS/lib/exe/fetch.php?media=dispersion.zip|Dispersion]] as a starting point and do the following: We use the example from the wiki [[https://wikihost.nscl.msu.edu/JIOSS/lib/exe/fetch.php?media=dispersion.zip|Dispersion]] as a starting point and do the following:
 +
 1, Find the lines as shown in the picture below: 1, Find the lines as shown in the picture below:
 {{:dispersion_ele.png?direct&400|}} {{:dispersion_ele.png?direct&400|}}
 +
 In the picture above, each of the commands (DL, DP, MQ ...) represents an ion optics element. (For a complete reference of the commands used in the cosy script, one has to refer to the manual). Here in the step 3 of [[https://wikihost.nscl.msu.edu/JIOSS/lib/exe/fetch.php?media=project_for_the_jina_ion_optics_for_recoil_separator_school_v4.pdf|this project]], what we want is very simple:a drift, 45-degree dipole magnet with a 1 meter bending In the picture above, each of the commands (DL, DP, MQ ...) represents an ion optics element. (For a complete reference of the commands used in the cosy script, one has to refer to the manual). Here in the step 3 of [[https://wikihost.nscl.msu.edu/JIOSS/lib/exe/fetch.php?media=project_for_the_jina_ion_optics_for_recoil_separator_school_v4.pdf|this project]], what we want is very simple:a drift, 45-degree dipole magnet with a 1 meter bending
 radius and a drift. So we modify this part of the script as shown in the picture below: radius and a drift. So we modify this part of the script as shown in the picture below:
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 **Q4.** **Q4.**
  
-In step 4, we calculate the reaction kinematics for the 15O(a,g)19Ne reaction at 57MeV (~3MeV/u) in the lab system. +In step 4, we calculate the reaction kinematics for the 15O(a,g)19Ne (Q=3528.47MeV) reaction at 57MeV (~3MeV/u) in the lab system. 
 {{ :3mev15o.png?direct&400 |}} {{ :3mev15o.png?direct&400 |}}
  
-The energy spread in this case is about +-2% (maximum energy acceptance of SECAR is +-3.1%), and the angular spread is ~ +-10mrad (maximum angular acceptance of SECAR ~ +- 25mrad). At this energy the reaction products fit in our systems acceptance without any problem. However, at lower beam energies the energy spread becomes larger. The estimated minimum energy for fitting the acceptance is ~0.5MeV/u in the lab system.+The energy spread in this case is about +-2% (maximum energy acceptance of SECAR: +-3.1%), and the angular spread is ~ +-10mrad (maximum angular acceptance of SECAR: +- 25mrad). At this energy the reaction products fit in our system without any problem.  
 + 
 +The maximum energy that we can go until we reach the maximum energy acceptance of SECAR is ~8.2 MeV/u. 
 +For reaching the maximum angular acceptance we need energies above 20MeV/u. 
 + 
 + 
 + 
 +* all energies are in the lab system. 
 + 
 + 
 +{{ :gammas19ne.png?direct&400 |}}
  
 -------------- --------------
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- **Q6.** +**Q6.** 
          
 {{ :parabola.png?direct&400 |}} {{ :parabola.png?direct&400 |}}
      
      
-  We got our data by varying the field of the quadrupole Q7 in the simplified SECAR model "emittance_script.fox" (link: [[download_the_tutorial_files|]]).+We got our data by varying the field of the quadrupole Q7 in the simplified SECAR model "emittance_script.fox" (link: [[download_the_tutorial_files|]]).   
 +For getting  Xmax we used the command: 
 +WRITE 6 'VMAX' VMAX(RAY(1));
      
-  For getting  Xmax we used the command: +For calculating the emittance we used the following equations:
-  WRITE 6 'VMAX' VMAX(RAY(1)); +
-   +
-  For calculating the emittance we used the following equations:+
   s11 = P1/L^2     s11 = P1/L^2  
   s12 = (P2 - 2*P1/L)/ 2*L^2   s12 = (P2 - 2*P1/L)/ 2*L^2
-  s22 = P3/L^2 - P1/L^4    +  s22 = P3/L^2 - P1/L^4     
-   +where P1, P2, P3 are the fit parameters that we found (see the image above). These equations were derived using the supporting materials from here: [[download_the_tutorial_files|]]
-  where P1, P2, P3 are the fit parameters that we found (see the image above). These equations were dirived using the supporting materials from here: [[download_the_tutorial_files|]]+
  
  
-  Using these equations and numbers we get:  +Using these equations and numbers we get:  
 + 
   epsilon = sqrt (s11*s22 - s12*s12) = 2.19e-7 m*rad = 0.219 mm*mrad   epsilon = sqrt (s11*s22 - s12*s12) = 2.19e-7 m*rad = 0.219 mm*mrad
      
- **Correction**:  +**Correction**:  
-  the equation s22 needs to be replaced by s22 = P3 -s11 -2*Ls12)/L^2  +the equation s22 needs to be replaced by s22 = P3 -s11 -2*Ls12)/L^2  
-   + 
-  For getting the correct parabola one should plot the quantity K=Gradient*Leff/Brho on the horizontal axis. +For getting the correct parabola one should plot the quantity K=Gradient*Leff/Brho on the horizontal axis. 
-   + 
-  By repeating the process using the above corrections we got: epsilon=0.45mm*mrad  +By repeating the process using the above corrections we got: epsilon=0.47mm*mrad  
-  By increasing the quality of the fit the number should go closer to 0.3mm*mrad + 
-  +By using more precise fit parameters in the calculation (excel returns rounded values) the number should go closer to 0.3mm*mrad 
 + 
 +The nominal value of epsilon according to the ".fox" file is: epsilon=XX*AX= 0.001*0.0002 = 0.2 mm*mrad 
  
-  The nominal value of epsilon according to the .fox file is: epsilon=XX*AX= 0.001*0.0002 = 0.2 mm*mrad  +You can perform these calculations using this spreadsheet: {{ :tripleg_emit.xlsx |}}
-    +
-    +
-   You can perform these calculations using this spreadsheet: +
-{{ :tripleg_emit.xlsx |}}  +
    
  
/srv/thewikis/JIOSS/data/attic/tripleg_group.1536899421.txt.gz · Last modified: 2018/09/14 00:30 by gastis

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