Dear all,
as most of you have heard, known deteriorations force us to plan a factory repair
of the G10 and G11 gyrotrons at some point. The decision has been made to send
G10 back at the beginning of January 2026 and to install the new gyrotron (due to arrive
in December) in its place - in practice then this means our gyrotron inventory will not change,
except
    - 
the new G10 will have to be commissioned and this cannot be guaranteed to be 
    completed by the start of operations in 2026, but will nevertheless be faster than
    if we had to debug all the infrastructure that is being put in place for G12; we can tentatively
    aim for early March
    - we shall no longer have limitations in X3 power on G10

We expect the repaired gyrotron to be back sometime in the summer. Our intention would be to
send G11 to Thales at the start of the longer opening planned for the TBLLD installation, tentatively
set for late summer, although this is not confirmed at the present time. In that case, in practice we can 
expect to have an actual increase in X2 and X3 power (and good reliability for all gyrotrons) around early 2027. 
(As a reminder, a fourth dual-frequency gyrotron is then also expected for late 2027.)

For the remainder of the current campaign, please keep in mind the current limitations for X3-10:
- maximum power 480 kW for 2-s pulse
- at 500 kW, pulse length limited to 370 ms
- at 610 kW, pulse length limited to 300 ms
- at 730 kW, pulse length limited to 230 ms
- at 810 kW (maximum allowed), pulse length limited to 210 ms
and remember that if G11 is in use during the same time window, it will have the same power
as G10.

    Stefano

-- 
Dr. Stefano Coda
Swiss Federal Institute of Technology
EPFL SB SPC, Station 13, CH-1015 Lausanne, Switzerland
Tel.    (+41) 21 693 3463
E-Mail  Stefano.Coda@epfl.ch