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Message ID: 484     Entry time: Sun Nov 27 12:30:41 2016
Author: AE, PV 
Subject: Energy loss in Degraders and Implantation for runs 1028 and 1033 

Implantation profile in AIDA

    BigRIPS file 1028 (Attachment run1028.png):  Degrader setting: 3 mm Pb(fix) + 0.8 mm W(variable) + 2 mm Al(variable)

    BigRIPS file 1033 (Attachment run1033.png):  Degrader setting: 3 mm Pb(fix) + 0.8 mm W(variable) + 2 mm Al(variable) + 1 mm Al(fix)

    BigRIPS file 1012 is in https://elog.ph.ed.ac.uk/AIDA/478 Degrader setting: 3 mm Pb(fix) + 1.3 mm W(variable) + 2 mm Al(variable)

    Observation: Some Mg isotopes (38, 40) is implanted in last DSSD or out the DSSD stacks. We may need to add more degrader!

 

Equivalent thickness of W, Pb and Al degraders

   The measured implantation profiles agree with LISE estiamtes for the equivalent change in implantation depth for W, Pb and Al. These were estimated with LISE by comparing change of range in Si for 1mm   degrader of each material (see attachments). Note that W produces a larger change in range than Pb (higher density; according to LISE database).

     1 mm Al: 1.15 mm in Si

     1 mm W: 5.40 mm in Si

     1 mm Pb: 3.05 mm in Si

The current configuration (run Mg401033) gives:

    3 mm Pb + 0.8 mm W + 3 mm Al  = 16.9 mm Si

Probably our best alternative (unless we can go in and rearrange fixed degraders) is:

   3 mm Pb + 1.3 mm W + 3 mm Al = 19.6 mm Si: move implantation depth 2.7 mm upstream

Here is a spreadsheet where you can play with the numbers and create test your own solution to the puzzle: https://docs.google.com/spreadsheets/d/1QJp8t98sT3pExAQb3xtHtAvk4TUDVO6alhbLIaNtx8A/edit?usp=sharing

 !!! We did change degrader for the 3mmPb+1.3mmW+3mmAl setting at 22.16 (from AIDA run 26_0); see elog entry https://elog.ph.ed.ac.uk/AIDA/483

Attachment 1: run1028.png  28 kB  | Hide | Hide all
run1028.png
Attachment 2: run1033.png  27 kB  | Hide | Hide all
run1033.png
Attachment 3: 0mm.JPG  168 kB  Uploaded Sun Nov 27 19:11:57 2016  | Hide | Hide all
0mm.JPG
Attachment 4: 1mmPb.JPG  162 kB  Uploaded Sun Nov 27 19:12:06 2016  | Hide | Hide all
1mmPb.JPG
Attachment 5: 1mmW.JPG  166 kB  Uploaded Sun Nov 27 19:12:15 2016  | Hide | Hide all
1mmW.JPG
Attachment 6: 1mmAl.JPG  162 kB  Uploaded Sun Nov 27 19:12:15 2016  | Hide | Hide all
1mmAl.JPG
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