JINA-CEE ION OPTICS SUMMER SCHOOL: JIOSS 2018

User Tools

Site Tools

Trace:
tripleg_group

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision 		Previous revision
tripleg_group [2018/09/14 00:33]
gastis 		tripleg_group [2018/09/14 09:32] (current)
gao
Line 1: Line 1:
-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:
Line 40: Line 41:
 **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 |}}
  
 -------------- --------------
Line 66: Line 77:
   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 dirived 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 derived 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 increasing the quality of the fit the number should go closer to 0.3mm*mrad +By repeating the process using the above corrections we got: epsilon=0.47mm*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: +By using more precise fit parameters in the calculation (excel returns rounded values) the number should go closer to 0.3mm*mrad 
-{{ :tripleg_emit.xlsx |}}  + 
 +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 |}}
    
  
/srv/thewikis/JIOSS/data/attic/tripleg_group.1536899583.txt.gz · Last modified: 2018/09/14 00:33 by gastis

Page Tools

Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Share Alike 4.0 International
CC Attribution-Share Alike 4.0 International Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki