ROGER OTTE REMEMBERED

Roger Otte passed away on December 11, 1997, after a long struggle with multiple myeloma. He was long-time operations manager at the Tantalus storage ring and at Aladdin, until his retirement in 1995. To many students, postdocs, and visitors at Tantalus and Aladdin he was like a father, introducing them to the world of synchrotron radiation and to life around it. He will be remembered by many of us who have me\made synchrotron radiation their career. Here are a few reminiscences from colleagues:

"More than anyone else, Roger was responsible for making SRC 'user friendly' for young scientists."

"Roger was always a gentleman (and a gentle man). I never saw him show any frustration-even when things were not going well."

"During the battle for the survival of Aladdin, Roger was in charge of many things and in particular of completing the shielding. Unfortunately, he suffered a heart attack which put him out of business for a while. This emphasized how much work Roger was doing for the success of the project, and how extremely difficult would have been to replace him. In fact, he was not fully replaced: we had to patch up things but could not match the quality and quantity of his contributions. On the other hand, the health crisis also emphasized Roger's dedication to the project and to his work in general. It was very difficult to keep him quiet for the minimum time required by his situation, and he was back to the front line as soon as he could. I remember how touched we all were by what Roger did: it was a great boost to the morale."

NEW UNDULATOR BEAM LINE BEING INSTALLED

Coordinated by Greg Rogers, a new undulator beam line for high resolution valence photoemission is taking shape. It consists of an electromagnetic undulator and a high-resolution normal incidence monochromator. This project is a joint, NSF-funded effort involving SRC and several users with Juan Carlos Campuzano (University of Illinois-Chicago) as Principal Investigator.

The SRC undulator was transported from PSL to SRC in late January. In situ personnel radiation shielding of the device has been completed. At the present time surveying and alignment, connections of electrical power and cooling, and integration of control circuitry and software are in progress. During March the machine trials are scheduled.

The PRT-SRC 4m NIM beamline is nearing completion. It will have an energy range from 6 to 50 eV with a resolving power up to 3 x 10^4, and throughput up to 3 x 10^11 photons/sec. The grating chamber and slits are currently under testing at McPherson Inc., and are scheduled for delivery in early April '98. Most other components are finished and in position at the SRC, including two beam position monitors which will be used to document the undulator light in the next several weeks. Testing of the beamline will begin in July, and it will be turned over to users in September of '98.

QUADRUPLE COINCIDENCES AT THE DCM

For a complete photochemistry experiment, one would like to detect all the products that a photon creates after being absorbed by a molecule, such as photoelectrons, ions, and molecular fragments. The more of these fragments that can be detected in coincidence, the closer one gets to the ideal experiment.

Adam Hitchcock and coworkers at McMaster University have pushed the field to quadruple coincidences, detecting coincidences between a photoelectron and the three photoions of the carbon-oxygen-sulfur molecule following S 1s core excitation at 2472 eV. For atomic physicists, this is comparable to a quadruple jump at the Winter Olympics. This work is aimed at breaking bonds selectively by excitations from core levels of specific atoms in a molecule.

MAGNETIC LINEAR DICHROISM

For determining the magnetization in thin films element-by-element, magnetic circular dichroism (MCD) bas become the technique of choice in recent years. Markus Schwickert and G. R. Harp (Ohio University) demonstrated magnetic linear dichroism (MLD) in Co, Fe, Cr, and V thin films. The success of this experiment is owed to the very high stability of the flux on the HERMON beamline at the SRC, which allowed measurements of differences smaller than 0.0004 of the absorption signal. The MLD effect scales approximately as the magnetization squared, in agreement with theory, which makes antiferromagnetic samples accessible that cannot be probed by MCD.

COMPUTER HELP DESK ESTABLISHED

A help desk has been established at the SRC to assist with computing and data conversion. It can be reached at 2306 or help@src.wisc.edu. The desk is being staffed by Isaac Pentimaki.

HONORS FOR SRC RESEARCHER

Mike Bancroft, University of Western Ontario chemistry professor, has won the Morley Award from the American Chemical Society. On May 27, 1998, Prof. Bancroft will receive the award, the highest award given by the Cleveland section of the society. A symposium involving his work photoelectron and Mössbauer spectroscopies in inorganic chemistry and geochemistry will be held the same weekend. The award, which recognizes significant contributions to chemistry made by someone within 250 miles of Cleveland, is named for the late pioneering chemist Edward Morley, the founding chairman of the Cleveland Section who made significant contributions to science. The award consists of $2000 and a gold medallion.