Introduction

This document explains the role of the BM29 web pages and how to use them, as well as some of the FAQs (frequently asked questions).

Aim of the BM29 web pages

The idea of the BM29 web page is to supply the user of BM29 with as much information necessary to successfully and safely operate the beamline on his own. The pages should as well serve as a tool to the user to prepare a proposal and later in the perparation phase of the experiment. It is not the role to explain X-ray Absorption Spectroscopy (XAS) as a method, though we have the intention to explain some point which are essential for good quality spectra, but never discussed in textbooks.

The last role is to document the work done on the instrumentation, software, control, sample environment, etc. and in particular to maintain a certain level of knowledge even when staff changes.

What do you have to know as a user

The level of preparation necessary to perform a successful experiment clearly depends again on your general knowledge of XAS and your experience on other facilities/experimental stations. It is not the role of this document, neither of the beamline staff, to teach you to perform an XAS experiment. There are a lot of textbooks on the topic, some of them mentioned here.

Before you come to BM29 to perform an experiment, you should read the web pages and the manuals concerning the equipment that you want to use. There is a whole standard transmission experiment described, which should make you quite familiar with the operation, concepts and programs in use.

Of course, we are there to help you performing your experiment as described below. In particular our role is to help you to start your experiment and to assist you in case of problems. This concerns in the first place of course problems associated with the beamline.

We can not explain you all the soft- and hardware once you are at the beamline. There is a lot of time involved and this time is in the first place lost for your experiment. You are supposed to conduct your experiment on your own and you need to train yourself in order to be able to do so. So please read this pages carefully before coming to the beamline. Although some things may be different from what you find in the pages, either because it takes quite some time to up-date the information or we needed to change the localion of a particular equipment, etc., the principle steps/ operation should not be influenced by this. Again, you need to be familiar with the concepts, more than with a particular computer program or command. It is not our role to do the experiment for a user, and you gain a lot of time if you know already how to operate the system.

Our experience has shown that some things are much easier to learn by doing, to understand the operation by having it demonstrated with the instrument in front of you. But again, it's your time, more than our, and it help a lot to be already familiar with the documentation.

How should you use this document

Of course, we do not expect you to know all aspects of the instrument. The level of preparation necessary to perform a successful experiment clearly depends on your general knowledge of X-ray Absorption Spectroscopy and your experience on other facilities/experimental stations.

We suggest you to start to get a feeling for performing an experiment by having a look on the description of a Standard experiment. After you should inform you in more detail on the specific equipment you would like to use, like the cryostat, oven, etc. If you are not familiar with some of the concepts/programs used, please get more information using the links suggested.

We recomment this well before you come to the ESRF (> 6 weeks), so that there is enough time to sort out possible problems. You are welcome to ask your local contact for advice. It is always good idea to check the possibilities and concepts of the beamline before you want to write a proposal.

You should check the week before coming to the ESRF that there are no changes or news available. During your experiment, the web pages should serve you as an instruction manual and help to solve problems.

What is the role of your local contact / BM29 staff

The BM29 staff is there to help you performing your experiment. This role is in the first place associated to your local contact. For experiments envolving groups coming to the ESRF since some time already, we try to choose the same local contact assuming that the experience of the former experiment helps to have smooth operation. As we try to regroup similar experiments to avoid crystal change in the monochromator, set-up times for high pressure or oven experiment, etc., this may not always be possible though.

We are happy to give our comment on problems that occur with the Physics (or Chemistry etc...) of your samples if we feel that we are able to do so. We are always trying to offer you the beamline in the best possible state for your experiment, taken into account the workload of the staff. On the other side, we have to point out that we are not responsible for the quality of your sample or the data, if problems are not instrument related, but can be traced back to the sample or equipment that you brought to BM29.

Working on an experiment always involves problems and solving of these problems. We will help you to do so if you encounter a problem, both the scientific, as well as the technical staff. But please remember that due to the limited staff and high workload, we can not in particular design sample environments or non-standard electronics for your experiment, (i.e. electronics available at the beamline or from the pool of the ISG (Instrument Support Group)), neither produce/machine it. We are of course able to adapt equipment on-site (like producing an adapter plate to mount equipment on our experimental tables, or an interface cable to drive a motor via our control system). In any case, such questions can be solved beforehand and you can gain time for your experiment if you contact your local contact well before the start of your experiment.

It is not the role of the local contact to analyse your data. Again we are happy if you want to discuss with us concerning the analysis, and give you support to some extent. All work and request which exceeds the standard level of service need to be discussed and agreed with the persons concerned in advance and it is a question of the interests and available time of your contact to give you additional help in the framework of a collaboration.

When and how can I ask the local contact for help

As pointed out, the local contact is not there to perform your experiment for you. After the set-up, you should be able to work on your own. Your local contact will try to solve problems, like set-up, macro programming, electronics, etc. with you.

In case of a problem, you should first try to understand yourself why things go wrong. A lot of things are explained or are going to be explained in the future on the web pages. A classical example is that you have no counts in the detectors. You should check yourself all obvious possibilities before calling for your local contact (like no beam due to re-injection, beam lost, front end closed/failure, problems with the monochromator (Piezo), sample centering (in the case that you have counts in I0 but not I1), etc.).

If you do not understand what is going on or it takes you too much time to find a solution, you can contact your local contact in his office. If you don't have a persons phone number you find it on the contact web page.

After working hours, you can reach your local contact at the beamline portable phone (0688387054). In this case you can contact him for advice till 10 p.m., if no other agreement was arranged. In general we will try to solve the problem over the phone. If it is not possible to solve a problem via phone, your local contact will in general agree to come to help you till 10 p.m. (again, if there was no other agreement).

On weekends you are supposed to work independently. In general the local contact will phone you to ask if everything is fine. In case of problems that you can not solve, you can call him to get help like on normal working days. There will always be a local contact available (an exception being a user group coming to the beamline since years... in this case, there may different agreements, but in any case, the local contact will inform you if he should not be available for some time, etc.). In the case you can not get help, you may try to get help from the floor coordinator (25-25). This is your official help on week-ends anyway, but on most problems concerned with the beamline control, the fastest solution should be to get help from the local contact.

You need the help of a technician

During the preparation of an experiment, please address your requests via the local contact, so that the work of the technicians can be coordinated. Once you are working on the experiment, the technicians will try to solve problems with respect to their time schedule and can be contacted directly. Problem solving of on-going experiments have priority, but again, we are very limited in resources and a request on a Friday afternoon at 4 p.m. is likely to be unsuccessful. There is no support from technicians after working hours (normally 5 p.m.) and on week-ends.

You are not able to contact the local contact

In the case that you can not reach your local contact during working hours on site, check the absence page. Try to contact one of the other staff members who will give you assistance. If this is not successfull, contact the floor coordinator and ask for help.

'Operator specific' information

In addition to the general standard information needed to operate the beamline on a user level, we will try to add over the time more specific information needed to operate the beamline on a lower level system - so to say an operator/local contact level. The idea is to create a documentation that should survive changes of beamline resonsibles (well, we here suppose that the beamline responsible knows about everything at the beamline) and the other staff and to minimise the loss of information/knowledge associated with this.