The OPAL Discussion Forum

[douguoliang <douguoliang AT impcas.ac.cn>]

Hi, all

I'm using 3D electric field to simulate the straight-sector cyclotron. But I found that there is a certain difference between the energy gain and the design value.

Before that, the 3D E-field files is exported from CST. The peak voltage value in the model is 160kV, so I set the ESCALE to 0.75 to make it consistent with the design peak voltage of 120kV. And I also have set the right PHIINT.

From the OPAL's output ,I can get the energy gain per turn. And from the CST, I can get the gap voltage by the curve integral(Figure 1). I found that from OPAL's output that the energy gain per turn is less than the energy of the CST gap voltage. So, I convert the energy gain per turn into the gap voltage actually felt by the particles according to the particle charge and gap numbers. We can see that the trends are consistent but there is a difference of about 10kV between them(Figure 2) .

I checked the 3D E-field file before input OPAL and the 3D electric field file at t=0 output using DUMPEMFIELDS command. But there is nearly no difference between them(Figure 3,4,5). 

So I don't know what is the reason for such a difference, can anyone help me to answer it?

The all figures are in the attachment.

Best regards, 

Guoliang Dou

	douguoliang
douguoliang AT impcas.ac.cn

Attachment: attachment.zip
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