Commission on Small-Angle Scattering

Background history and prospect 

Growing a thriving international community for small-angle scattering through collaboration

by Jill Trewhella*

School of Life and Environmental Sciences, The University of Sydney, Building G08, Camperdown, NSW 2006, Australia.

Correspondence e-mail:

Small-angle scattering emerged as a tool for studying noncrystalline structures from early observations around 1930 that there was a relationship between the extent of the scattering and the size of the scattering object. Andre´ Guinier, a leading figure in the development of the field, noted in his summary findings from the first Conference on Small Angle Scattering in 1958 that the technique would be of value to study ‘submicroscopical inhomogeneities’ and further provided a means of ‘observation [that had] in the past restricted the field of application of the X-ray method.’ In 1965 the first of what became a highly successful series of Small-Angle Scattering (SAS) meetings held approximately
every three years took place in Syracuse, NY, USA, and many of these ongoing meetings published their proceedings and highlights in the International Union of Crystallography (IUCr) Journal of Applied Crystallography. Since the early 2000s, the relationship between the international SAS community represented at the triennial SAS meetings and the IUCr has been strengthened and deepened through formal cooperation and collaboration in a number of mutually beneficial activities that have supported the growth and health of the
field and the IUCr.

Links for full article:

The beginnings (July 1995)

A number of members of the ACA Small-Angle Special Interest Group gathered at the 1995 ACA meeting in Montreal to discuss the desirability of setting up a broader international group to further the interests of researchers in this area. The group determined that forming a commission within the International Union of Crystallography would be the most appropriate method. This led to the designation of a working group to handle the nuts and bolts of the matter. The co-chairs of the working group were D. John Barnes of the USA and Dr. Terence Sabine of Australia.

Spadework (August 1995 - July 1996)

Dr. Barnes established a World Wide Web Site and an Internet listserver as communications tools for reaching out to the broader international SAS community. The listserver permits interested parties to join a mailing list and to post messages to it that are distributed to all subscribers. The web site you are now visiting is a repository for documents pertaining to the Commission.

In late November Dr.Barnes received a letter from the secretary of the U. S. National Committee on Crystallography indicating that this body supported the development of the Commission. Given that there were no formal terms of reference Dr. Barnes decided that contact with other national committees was premature.

Suggestions for individuals to join the working group were solicited and leading international figures in SAS were recruited. Discussions regarding the scope of the proposed Commission's activities were held by electronic mail.

The formal proposal (22 July 1996)

The working group met face to face in conjunction with the 10th International Conference on Small-Angle Scattering in Campinas, Brazil on 22 July 1996. All members except Sabine and Osamura were present. The group prepared a revised draft terms of reference and discussed the next steps to be taken. The result of these deliberations was presented to the assemblage in a special plenary talk. Copies of the new terms of reference were available to anyone who was interested. Those members of the audience who did offer comments indicated enthusiastic support, indicating that the group should pursue its objectives until a full-fledged Commission is established. It should be noted that the 200 or so members of the community who were present at the conference represented a very broad cross-section of the worldwide community of SAS devotees.

Jeff Penfold replaced Julia Higgins on the working group. Julia cited the press of other business in asking to be relieved. The working group proposed that its members be designated as the initial members of the Ad Interim Commission until they are replaced by an election process that is expected to turn over about 1/3 of the membership at each election. The frequency of elections, the duration of terms of office, and procedures for designating the officers of the Commission will be specified as soon as we can examine relevant IUCr documents pertaining to these matters.

Ratification in Seattle (14 August 1996)

Dr. Barnes forwarded the new terms of reference and the proposed membership of the Ad Interim Commission to the responsible parties within the IUCr at the XVII Congress in Seattle. The report was received enthusiastically by the IUCr executive committee, whose chair, Dr. Philip Coppens, had been extremely supportive throughout the early going.The IUCr General Assembly approved the submissions and voted to form a permanent Commission at its meeting on 14 August 1996.


Action by the IUCr Executive Committee (August 15th 1995)

The letter from Dr. Philip Coppens reprinted below sets forth the steps that must be taken to bring this to fruition. Dr. Coppens was most generous in his assessment of the value of the activity and he pointed us to several sources of help.

August 15, 1995   Dr. John D. Barnes Spokesperson, Small-Angle Scattering Working Group Polymer Mechanics and Structure Group Bldg. 224, Rm. A209 NIST Gaithersburg, MD 20899     Dear John,

At its meeting in Lund, Sweden earlier this month the Executive Committee discussed the letter by you and other members of the Small-Angle Scattering Community, indicating your intention to work towards the establishment of a Commission on Small-Angle Scattering within the IUCr.

The Executive Committee wants to express its full support for the aims of the Working Group, and welcomes its intention to form a new IUCr Commission.

The National Committees and Commissions of the Union must be notified at least four months in advance of the General Assembly that a new Commission will be proposed. We request at this time that the Working Group submit a list of names specifying the proposed Chairman, and membership, and a draft terms of reference detailing the aims of the Commission. Anne Cawley of our Chester office will forward you relevant information that should be helpful in formulating the terms of reference.

If the information from you is received in time, the Executive Committee will be able to approve the formation of an Ad-interim Commission, which can subsequently be approved as a regular Commission by the General Assembly in Seattle. Alternatively the Ad-interim Commission could be formed at the time of the Seattle Congress, for final approval in 1999 by the General Assembly in Glasgow.

I hope the above gives you the information needed to proceed. Please do not hesitate to contact Michael Dacombe, Anne Cawley or myself if you have further questions.

Sincerely Yours (signed) Philip Coppens Philip Coppens President, International Union of Crystallography

What is a Commission?

From the sa_scat newsletter of 25 August 1995.

What is a Commission?

Others who know more about these things can jump in and correct me if they wish, but here is my understanding to date:

A Commission of the IUCr is a small group of people who look after the interests of a particular area of interest to crystallographers worldwide. Examples of existing commissions that come immediately to mind include the ones on Neutron Diffraction, Powder Diffraction, Small Molecules, and Journals. There are others, but this list gives you the flavor of the thing.

Why do we have them?

Each Commission lives by its "Terms of Reference." I have reviewed a couple of examples of these and I intend to review some more. There are certain common themes (arranging meetings, maintaining software libraries, etc.). The purposes are certainly worthy and they tend to advance the interests of workers in the field. I think that all of us can appreciate the value of an ongoing forum to facilitate communications.

Who serves on Commissions?

As nearly as I can tell the members of commissions are elected for terms of a fixed duration and there are term limits that guarantee turnover in the membership. There are also issues of diversity that are important to the composition of a commission. Serving on a commission is certainly an honor, and competence is certainly important, but it seems to me that logic dictates that at least some of the members be consummate bureaucrats if a commission is to get its work done.

This brings us to the concrete suggestion that Dr. Coppens made - namely that we nominate a chair and a set of members for an Ad Interim Commission and that we charge this group with developing a consensus on the terms of reference in time for final approval by the time of next year's IUCr Congress in Seattle. Based on suggestions that I have seen it would be appropriate to have somewhere between 5 and 7 members on this Ad Interim Commission. The working group needs to have the roster and a draft terms of reference completed by around 1 December in order to get the issue of final approval on the agenda in Seattle next August. Given the wonders of modern electronic communication this should be possible.

There is a certain amount of spadework involved in circulating the draft terms of reference to the various secretaries of National Committees on Crystallography. I have learned that the U.S. National Committee is affiliated with the National Research Council and that it will be meeting in November.

I see no reason why we cannot put the formation of the Commission on Small Angle Scattering on a fast track, given the warm support that Dr. Coppens has expressed for the efforts that have been made to date. In order to do so we will need to reach out much further than this little listserver is currently able to. We need many more names on the distribution list. The growth to date has been gratifying, but we need much broader international representation and we need more of the movers and shakers in the field.

I urge each of you to send e-mail messages to as many of your colleagues as possible encouraging them to subscribe to this listserver. It might be a good idea to forward some of the propaganda that I have already sent out so that they can appreciate the value of the thing.

I would like to emphasize e-mail as the primary communications medium for the time being because I find Snail Mail to be very inconvenient (and slow). It should not be too difficult to build up the subscription base of the listserver to the point where it becomes sufficiently representative to form the needed consensus on the various issues that will be coming up.

Thank you for your attention.

John D. Barnes
22 August 1996


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