We're learning as we go at FACET but it's clear that a good beam time procedure helps the operators know what to deliver and helps the experimenters to focus on achieving results. The more experience we gain at running, the more we understand what constitutes a good procedure. So you can expect the "answer" to this to change as we learn.
All procedures need to be headed with the expected date and time of the beam time.
The procedure needs to be sent to Vitaly, Mark and Christine. The procedure will be reviewed and discussed with the experimenters if necessary (and it is usually necessary!). If approved, the procedure will be forwarded by Vitaly or a designee to Jerry Yocky who instructs the operators on how to prepare the beam.
1. A clear definition of what constitutes that the beam is ready for delivery to a given experiment.
This is a set of requirements on the
a) beam (charge, orbit, spot size, bunch length) and
b) required available diagnostics/hardware (TCAV…).
With regards beam parameters, explain what parameters are the critical ones. Give a tolerance where possible and indicate what is really essential to get any progress at all in the experiment and what is desirable to get the best data.
If you need it, ask for it, but if you don’t, don’t.
We do not want to get in a habit of saying we need something and then saying “well, I guess that’s good enough, we’ll take it”. At the same time we don’t want to hold off an experiment tuning on a parameter that isn’t really needed.
Although not needed within the document, be prepared to justify the requirements from a physics perspective.
2. A simple description of the measurements to be made, devices/parameters to be changed and rough durations.
Think of this as what you will go over with the operator before starting the measurements, e.g. “We will be measuring ___. To do this we will change ___. While we do this we need ___ to be monitored/held fixed. This will take approximately ____ hours.”
If the measurements require changing phases, magnets, waist locations etc it should be clearly listed.
3. A plan for the experimenters themselves.
This is an outline/plan to help the experimenters be ready to take data efficiently and is an extended version of (2). This document is for you the experimenters. Although this document will benefit from review and discussion with FACET management (Vitaly, Christine, Mark), in the end this is ‘for you’.
4. A definition of success.
This should define what subset of analysis will be completed quickly to understand what has been accomplished.
This analysis is important to present at the 8 o’clock meeting held at MCC as well as to communicate what has been seen with management and operations.
Think of this as a plot(s) or image(s) that are not (necessarily) ready for publication but can illustrate the data. This last point is important for two reasons:
1. Guide what changes, if any, are needed from the accelerator and
2. Discuss how much more beam time, if any, is needed to move forward or complete the measurement.
Please be somewhat specific as to the date/time analysis will be ready as that would help us schedule a meeting if one is required.