what does dp/Pmax>100% mean?

[Zhaoliangchao]

Dear Didier,

When I track a RFQ after a BEND in envelop mode, dp/Pmax>100% appears after some cells(like element 36,45). At the same time, dW-W<0,what does a
negative W mean?
And 2 curves are plot ion the phase-energy space in blue and black. What do they mean?

[Didier]

Dear Zhaoliangchao,

1 - In envelope mode, only transverse transport is relevant in RFQ cell element. That can be used especially to calculate the transverse input matched beam. Indeed envelope mode is not able to simulate the longitudinal space in a RFQ (it's just not possiblein envelope mode to create longitdinal emittance from CW beam). That can be done only in multiparticle mode.

2- The black curve corresponds to acceptance, but same remark, it's only relevant in multiparticle mode.

Regards,

Didier

[Zhaoliangchao]

Dear Didier,

Another problem happens when I use multiparticle mode with partran. A filed map is used to import the RFQ field. In this way, I can verify my design of a real RFQ. There is no problem in envelop mode and I do not have Toutatis yet.