TTF calculation / energy gain bug ?

[jlalleme]

Hello,
After a long period without using GenDTL, I am back on it > Trying to design a DTL for He2+ (3727 MeV, charge 2) ... from 8 to approx 30 MeV.
I got something till the end but running TraceWin, I figured out the E gain was not the one expected and found a TTF pretty low.

checking further, for the first cell I got:
Lc 5.6 cm (correct, beta lambda at 2 MeV/u and 352.2 MHz)
for E0 3.3 MV/m, TTF 0.37 (quite low!!!) for a charge 2 and phase -30 deg makes it Egain around 0.12 MeV as in the file (column dW) while output energy is 8.24 MeV (column W)....

Now, trying to have the same design (still running full DTL) but with charge 1 and half the mass (1863 MeV) and half the input energy (4 MeV).
The first cell results are:
Lc 5.6 cm still OK.
E0 kept 3.3 MV/m, TTF 0.67 (twice as before and values that makes more sense) and column dW 0.11 MeV and output energy W 4.11 MeV are in line....
My question is the following:
Should we always consider running a charge 1 particles scaling the mass accordingly ? As it looks like this "feature" (limitation) is coming from DTLFish ?

[Didier]

Dear JB,

Could you send me your GenDTL result file, that'll help me.

Regards,

Didier

[jlalleme]

Dear Didier,
Was just a first shot, trying the get similar geometries and power.
Now running a case with lower E0 to get less power consumption.
Attached the two output files. Charge 2 ran with 3.726 GeV mass and charge 1 ran with 1.863 GeV.
Thank you for the help !
Else, I can apparently make it thru with charge 1 !!!
Cheers,
JB

[Didier]

JB,

Sorry for my mistake, but that’s not what I needed to rebuild the whole chain, I need your gdtl file (GenDTL’s ini file).

Regards,

Didier

[jlalleme]

Re,
You mean the .gdtl file ?
I have overwritten the initial one... Here is a similar one giving the same calculation error.
Merci,
JB

Had to add a .txt extension to make it thru.

[Didier]

Dear JB,

I'm so sorry but your cel.txt file is missing, perhaps could you use the button "Send projet" in "Options" page.

Regards,

Didier