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tripleg_group [2018/09/14 00:23] gastis |
tripleg_group [2018/09/14 09:32] (current) gao |
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- | This is the tutorial written by the ' | + | This is the tutorial written by the ' |
In this tutorial, we will explain step by step how we work on the project [[https:// | In this tutorial, we will explain step by step how we work on the project [[https:// | ||
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**Q3.** | **Q3.** | ||
We use the example from the wiki [[https:// | We use the example from the wiki [[https:// | ||
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1, Find the lines as shown in the picture below: | 1, Find the lines as shown in the picture below: | ||
{{: | {{: | ||
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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:// | 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:// | ||
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, | + | In step 4, we calculate the reaction kinematics for the 15O(a, |
{{ : | {{ : | ||
- | 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 | + | 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 |
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+ | The maximum | ||
+ | For reaching the maximum angular acceptance we need energies above 20MeV/u. | ||
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+ | * all energies are in the lab system. | ||
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+ | {{ : | ||
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- | **Q6.** | + | **Q6.** |
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- | We created the parabola shown in the picture bellow were a second order polynomial function has been fitted on it: | + | |
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{{ : | {{ : | ||
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- | | + | We got our data by varying the field of the quadrupole Q7 in the simplified SECAR model " |
- | + | For getting | |
- | For getting | + | WRITE 6 ' |
- | WRITE 6 ' | + | |
- | + | ||
- | For calculating the emittance we used the following equations: | + | |
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+ | For calculating the emittance we used the following equations: | ||
s11 = P1/ | s11 = P1/ | ||
s12 = (P2 - 2*P1/L)/ 2*L^2 | s12 = (P2 - 2*P1/L)/ 2*L^2 | ||
- | s22 = P3/L^2 - P1/ | + | s22 = P3/L^2 - P1/ |
- | + | where P1, P2, P3 are the fit parameters that we found (see the image above). | |
- | | + | |
- | By using these numbers we get: | + | |
- | + | Using these equations and numbers we get: | |
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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 | ||
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- | **Correction**: | + | **Correction**: |
- | the equation s22 needs to be replaced by s22 = P3 -s11 -2*Ls12)/ | + | the equation s22 needs to be replaced by s22 = P3 -s11 -2*Ls12)/ |
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- | For getting the correct parabola one should plot the quantity K=Gradient*Leff/ | + | For getting the correct parabola one should plot the quantity K=Gradient*Leff/ |
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- | 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 |
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+ | By using more precise fit parameters in the calculation (excel returns rounded values) the number should go closer to 0.3mm*mrad | ||
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+ | The nominal value of epsilon according to the " | ||
- | 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: |
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- | You can perform these calculations using this spreadsheet: | + | |
- | {{ : | + | |