LCLS User Documentation

The goal of this documentation is to provide a single source of information for all stages of the LCLS experiment. Since the first experiments at LCLS, documentation has been written across a variety of locations. As a result, while there is a lot of good information out there, it can sometimes be hard to find, and it is not uncommon to run across an older, out-of-date, version. This current endeavor intends to simplify the search process by compiling all the available information on relevant topics into a single website. Where appropriate, additional references will also be listed at the bottom of the page.

How to read this documentation

This resource is organized into three categories of pages. While the documentation can be read in any order, this organization is intended to better highlight pieces of information relevant to each of these stages of the experimental process.

1. 'Before your experiment' pages
   This first category includes more in depth information about the theory behind various tools (both hardware and software) available at LCLS. Logistical considerations, such as how to setup SLAC Unix computing accounts, are also covered.
2. 'During your experiment' pages
   This second category of pages is meant to serve as a resource during the beamtime itself. Checklists and step-by-step guides are favored to provide concise, useful reminders which can be read quickly during the experiment.
3. 'After your experiment' pages
   The final category of pages is more analysis oriented and should be a helpful resource when reprocessing data. This again includes explanations of the tools and algorithms, as well as tips and tricks from the accumulated experience of LCLS users and staff.

Finally, certain pages may be divided into two (or more) sections. While initially this documentation may be heavily focused on data analysis and software, it is the hope that the scope grows to include instrument controls, and other aspects of the experiment. It makes sense to include this complementary information on the same page for certain topics - the divisions are then intended to make filtering the information easier.

How to contribute

When deciding to create this documentation, a decision was made to move away from the Confluence platform where other LCLS documentation has been hosted. A driving motivation for this decision was the desire to emphasize the review process. Major changes and new page entries are only incorporated after review by another person other than the page/change author. This serves many purposes but two above all:

• Pages are subject to review by a third-party for readability. This helps to ensure that the information, as presented, is comprehensible to scientists who may not be subject-matter experts on the particular topic.
• Communication and interaction with the user community is facilitated. Feedback, requests, and contributions are possible and encouraged from the wider community.

As this documentation is hosted through GitHub, the review process is managed through the creation of Pull Requests. If you would like to make a contribution please clone the repository, create a new branch, and open a pull request. By assigning reviewers you can ensure that certain members of the team read your contribution. Feedback and requests can also be submitted by creating an Issue in the repository.