How to see the beam in the storage ring

I have written some times about how a synchrotron works (underlining that I am not a physicist and what I write is what I understood from the explanation of other people). Also I have wrote about how can we saw the beam or its effects: visible beam, first xrays or fluorescent screens

But there is another way to see the beam: using an scope.

Today I have ask to know a little bit more what we can see from an scope that we are reading the signal:

vncviewer of an Agilent DSO80804B

But, 2 questions: who this signal is get and what does this mean?

This signal is get from a Fast Current Transformer (FCT) located in sector 02:

Very close to the dcct that is giving us the current of the beam in the machine status. This FCT is an inductor surrounding the vacuum chamber and what we see in the scope is the inducted current by the primary current given by the electron bunches.

In the scope picture we can see the bunches in one turn (about 900ns). But a bunch is not one of this eleven groups in the signal. They are composed by bunches.

May can help to see that by plots taken with taurus:

Equivalent to the vnc, but getting the data from a tango device server.

Zooming on one of this groups:

With this last picture we can see the bunches themselves. The bunches are separated by 2ns, and the linac is shutting in groups of 32 consecutive bunches and a gap of 24ns.

Also I have ask why this groups of bunches have different shapes like:

This 3 examples has been taken over different times during today's start up of the machine. This shapes can be explained because fine configuration or how the equipments works and their efficiency. In the best case, in a world of the theory, this groups would be absolutely squared.