The OPAL Discussion Forum

[alexander.brynes AT stfc.ac.uk]

Dear OPAL developers,

I am trying to add an SDDS wakefield file to a TravelingWave element in opal,
using the WAKE element and WAKEF attribute.

A few problems arose with importing the wake file. Once resolved, the
following error arose:

```
Error> *** User error detected by function "Quaternion::rotate()"
Error>     quaternion isn't unit quaternion. Norm: nan
Error>     quaternion isn't unit quaternion. Norm: nan
```
The wake file consists of two columns, z (m) and Wz (V/C). Even with the wake
amplitude set to zero the error still arose.

Could you please assist me in preparing the wakefield file and how to enable
tracking with wakes? I couldn't determine where the error above was arising
from.

Thanks in advance,
Alex