Hey Andrew! Thanks for answering! Does someone have experience in minimize energy instabilities in beamlines? Are you sure it's an energy instability and not an intensity one? It's quite rare to see energy instabilities from a well calibrated monochromator. All monochromators should be in a closed loop, if there really are energy instabilities, then it's either mechanical (the encoder or crystal is loose) or the closed loop parameters are wrong for the rotational motor and the mono is slipping out of the closed loop window. Yes, I'm sure. I'm certain most of this problem arises from thermal issues in the monochromator. For example, we control the temperature of our 1st crystal, but for the 2nd one there is kind of control, the tunning between them is not closed-looped through a MOSTAB or something, there is no kind of shielding for the Huber. Thus, I have several reasons to be concerned!
MX2, our new beamline devoted to MX experiments, are facing problems with energy drifts. As far as we could notice, theses drifts are results of the contribution from several sources - possibly electron beam movements, heating of optical elements, etc... Could well be, but these will result in intensity instabilities as opposed to energy ones Yes, this is evident in my data. LNLS is a 2nd generation machine with 4 straight sections available for insertion devices. MX2 is a 2T wiggler-based beamline and produces a peak flux of 10^11 photons/s. What I'd like to know, before start performing calculations, how far should I expect the heating of a non-cooled 2nd crystal affects energy? Does someone know cases of a few eVs drifts? The second crystal will have no effect on energy, it will have a major impact on intensity. We had extreme difficulties in stabilising and sheilding our Khozu second crystal from thermal drifts. We eventually gave up and installed a channel cut mono. The much simplier design is far more easy to work with.... Luck you! I'm in the start of the journey! I guess I'll have to try fix that first! :( Andrew, what kind of approach did you try to stabilize 2nd crystal? If you know someone else who could contribute in someway to this problem, please tell me. Thank you one more time, LS
