JINA-CEE ION OPTICS SUMMER SCHOOL: JIOSS 2018

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tripleg_group [2018/09/14 00:10]
gastis 		tripleg_group [2018/09/14 09:32] (current)
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-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]] +This is the tutorial written by the 'triple G' group!  
-In step 2, we chose the 15O+4He radiative capture reaction to study. 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:+ 
 +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.** 
 +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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    SB 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.025 0.0 0.0 0.0    SB 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.025 0.0 0.0 0.0
          
-4, After changing the beam energy spread, run the script again, we get the following result:+ After changing the beam energy spread, run the script again, we get the following result:
 {{::x_motion.png?direct&400|}}.  {{::x_motion.png?direct&400|}}. 
 Again, the result looks reasonable. Again, the result looks reasonable.
 5, In step 3c, we also need to calculate with the first order matrix elements the position of ions using. This can be done by the equation that we mentioned above. We write it down here again: 5, In step 3c, we also need to calculate with the first order matrix elements the position of ions using. This can be done by the equation that we mentioned above. We write it down here again:
      x1 = (x|x)x0 + (x|a)a0 + (x|y)y0 + (x|b|b0 + (x|l)l0 + (x|δk)δk0      x1 = (x|x)x0 + (x|a)a0 + (x|y)y0 + (x|b|b0 + (x|l)l0 + (x|δk)δk0
-6, In step 4, we calculate the reaction kinematics for the 15O(a,g)19Ne reaction at 57MeV (~3MeV/u) in the lab system. + 
 + 
 + 
 + 
 +**Q4.** 
 + 
 +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 |}}
  
 -------------- --------------
      
-  Tuesday, 11-Sep+   
 + **Q5.**  
 + 
 +Bibliography for the 15O(p,g)19Ne reaction: [[http://iopscience.iop.org/article/10.1086/507083]]
  
      
-  We completed part 6. We created the parabola shown in the picture bellow were a second order polynomial function has been fitted on it +**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: 
-  For getting  Xmax we added the line: +WRITE 6 'VMAX' VMAX(RAY(1));
-  WRITE 6 'VMAX' VMAX(RAY(1)); +
-  right before the command "ENDPROCEDURE;" in the "emittance_script.fox" file.  +
-   +
-  For calculating the emittance using the quadrupole variation method, we used the following equations:+
      
 +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   [Correction: s22 = (P3 -s11 -2*Ls12)/L^2 but plot Vmax^2 vs K=Gradient*Leff/Brho ] +  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). + 
-   + 
-   +Using these equations and numbers we get:  
-  By using these 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
      
-  The nominal value of epsilon according to the .fox file is: epsilon=XX*AX= 0.001*0.0002 = 0.2 mm*mrad  (which is very close to the value determined with the method above). +**Correction**:  
-    +the equation s22 needs to be replaced by s22 = P3 -s11 -2*Ls12)/L^2  
-   You can perform these calculations using this spreadsheet: + 
-{{ :tripleg_emit.xlsx |}}  +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=0.47mm*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  
 + 
 +You can perform these calculations using this spreadsheet: {{ :tripleg_emit.xlsx |}}
    
  
-   Wednesday, 12-Sep 
        
-   Thursday, 13-Sep+**Q7.** 
 1, Change the effective length of Q2, the resolving power degraded slightly.  1, Change the effective length of Q2, the resolving power degraded slightly. 
 2, To restore the optimum resolving power, change the field strength of Q2 accordingly. We don't do it by hand, we use the FIT tookit to do that for us. 2, To restore the optimum resolving power, change the field strength of Q2 accordingly. We don't do it by hand, we use the FIT tookit to do that for us.
/srv/thewikis/JIOSS/data/attic/tripleg_group.1536898237.txt.gz · Last modified: 2018/09/14 00:10 by gastis

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