CHESS, in its 22nd year of operations,conducted its 15th annual CHESS Users Meet-ing at Cornell University on June 18 and 19,2002. The meeting highlighted first experi-mental X-ray data from the new G wiggler sta-tions, first X-ray data on multilayers of unusu-ally high energy resolution, and a new kind ofvideo-based beam position monitoring systembuilt upon helium optical luminescence. Inaddition, there were two concurrently runningworkshops, titled “New Technology and In-novative Applications of Small Angle X-rayScattering” (Sol Gruner, organizer) and “High-Throughput Crystallography and Complemen-tary Methods” (Quan Hao and Richard Gillilan,organizers). About 125 individuals attendedthe meeting. This article contains some of thehighlights of the staff reports, invited talks andworkshops (see Figures 1–4).

Staff highlightsSol Gruner, CHESS director, reported that

in the last four years, 1263 different re-searchers worked under 394 unique proposals.On the basis of hours of beam time, CHESSusage has been roughly equally divided be-tween biological and non-biological science.Sol also reported that the organizations atCHESS are growing: there are 34 personsworking at CHESS, 13 in MacCHESS, andthree at G-line, plus about a dozen graduatestudents and approximately a dozen Cornellfaculty members. A new five-year renewal pro-posal was recently reviewed for CHESS and afive-year renewal proposal has been submittedfor MacCHESS.

Maury Tigner, director of the Laboratoryfor Elementary Particle Physics (formerlycalled the Laboratory for Nuclear Studies), de-scribed an anticipated year of activities duringwhich the CESR storage ring would start torun, for the first time, in the 1.8 to 3.7 GeVrange (per beam) for charmed quark studies.About 10 weeks of down time will be neededin early 2003 for the installation of five new

superconducting wigglers into CESR. The re-sultant charm running will be at too low abeam energy for CHESS X-ray users, so peri-ods of dedicated X-ray running and dedicatedhigh-energy physics running are planned. Thefirst dedicated X-ray runs are expected tobegin in January 2003.

Joel Brock, director of the new facultybeamlines at CHESS known as G-line, spokeof the progress using the “backfire” beam fromthe A/G-line wiggler. Since there are both elec-trons and positrons simultaneously orbiting inopposite directions in the storage ring, the wig-gler creates two oppositely directed X-raybeams. One of these beams feeds the CHESSA-stations and the other the G-stations. ErnieFontes (CHESS Assistant Director) and DetlefSmilgies (G-line staff scientist) described thedesign of temporary multilayer optics for G-line and on commissioning experiments ineach of the three hutches (G1, G2, and G3). Abeamline was sketched out in January byFontes, and with used CHESS components,publishable data from G1 were being obtainedby April. The four-month plan was expeditedby the safety committees and everyone atCHESS hustled to complete the setup in recordtime. In parallel, a new motion control anddata acquisition system based on industrialPCs and PCI boards was commissioned by theG-line team and basic instrumentation was in-stalled in all three G-line hutches. It is hopedthat the final G-line optics designed by the G-line group will be fully procured and ready forinstallation during the planned CESR downperiod in 2003.

Quan Hao, associate director for Mac-CHESS, reviewed progress related to the pro-tein crystallography beamlines. At monochro-matic wiggler station F1, a pair of dual ADSCQuantum 4 CCD detectors has been installed(Figure 5). The monochromator has also beenset to an energy 50 eV above the Br K edge, toallow fast SAD (Single-wavelength Anom-alous Diffraction) experiments to be conducted

MEETING REPORTS

CHESS 2002 Users’ Meeting

Vol. 15, No. 6, 2002, SYNCHROTRON RADIATION NEWS2

SRNSynchrotron Radiation NewsISSN 0894-0886 is published bi-monthly.Coden Code: SRN EFR

Heather Wagner, Managing EditorMaureen Williams, Advertising ManagerEd Cilurso, Production ManagerPatrick Hufnagle, Designer

Editorial ServicesSynchrotron Radiation News346 Meadowview DriveCollegeville, PA 19426, USATel/Fax: +1610 409 9082E-mail: srnews@bnl.gov

Advertising ServicesMaureen WilliamsP.O. Box 1547Surprise, AZ 85378-1547, USATel: +1 623 544 1698Fax: +1 623 544 1699E-mail: mwilliams@nni.com

Circulation and SubscriptionsTaylor & Francis Inc.325 Chestnut Street, 8th floorPhiladelphia, PA 19106, USATel: +1 215 625 8900Fax: +1 215 625 8914

The following subscriptions are available:Vol. 15 (2002), six issues.

Personal: €64 EUR, $72 USD, £48 GBP, $120 AUD, ¥13,500 JPY.

Institution: €480 EUR, $528 USD, £360 GBP, $912 AUD, ¥100,800 JPY.

The opinions expressed in SynchrotronRadiation News are not necessarily those of the editors or publishers.

with crystals soaked with bromide salts. Liq-uid nitrogen has been piped to the three crystal-lography hutches for the on-line low tempera-ture cryocoolers. A supercomputer consistingof a 128-processor Linux-based cluster fordata analysis was recently commissioned. As aresult of these and other improvements, the av-erage time of each user visit has dropped to 40hours and the time to collect a data set is typi-cally less than six hours. A FedEx data collec-tion system of mail-in crystallography is fullyimplemented and is in its first year of trial.There were about 140 MacCHESS-relatedpublications in the last year, including a num-

ber of structures making the covers of top-ranked journals.

Alexander Kazimirov, CHESS staff scien-tist, spoke of progress with multilayer optics.He observed that CHESS has more beamlinesrunning on multilayer optics than any other SRlaboratory (5 of 12 stations or 42 percent).CHESS has separate collaborations with AlMacrander’s group at APS and with Osmic todevelop a number of specialized multilayer op-tics that are well matched to the CHESS sourceand its scientific interests. Kazimirov reportedtest results on low-contrast Osmic multilayerswith the number of periods varying from 500to 800. One particular sample, consisting of500 bilayers of a 31.5 Å period on a glass sub-strate, gave a measured reflectivity of 50 per-cent at 8 keV and a bandwidth (fwhm) of 0.29percent for deltaE/E (shown in Figure 6). Suchhigh-resolution multilayers would be very use-ful for crystallography where more flux can beobtained than from a Si 111 type of optic, yetwith enough resolution for protein crystallog-raphy and perhaps even useful enough forvirus crystallography when the developmentwork is finished.

Peter Revesz, CHESS’ new instrumenta-tion staff scientist, showed how visible light lu-minescence from helium gas can be imagedwith a video camera and used for X-ray beamposition monitoring with good vertical resolu-tion (better than 5 microns). Developments arein progress to utilize the same method for hor-izontal beam position monitoring. Construc-tion of new permanent monitors for the F andG wigglers and the F3 bending magnet line isunderway for the summer shutdown.

Charles Sinclair, project manager for theEnergy Recovery Linac project (recently ar-rived from the Thomas Jefferson National Ac-celerator Facility (Jefferson Laboratory), gavean update on the Cornell University plans, incollaboration with Jefferson Laboratory, tobuild a synchrotron light source based on theuse of energy recovery [1]. An ERL light sourcewould provide considerably higher averagebrilliance and far shorter duration X-ray pulsesthan is possible with a storage ring. However,many challenging accelerator physics and

technology issues must be understood and re-solved before a high-brilliance, full-energyERL light source could be built. Cornell Uni-versity is awaiting a final decision on a pro-posal to the NSF to build a prototype 100 MeV,100 mA ERL to explore and develop ERL lightsource technology.

Staff reports were followed by invitedtalks from users. David Allara (Penn State) dis-cussed molecules as electronic materials, theultimate terminus of the race for electronicminiaturization. While single molecule transis-tors were very recently demonstrated, mostmolecular electronics involve studying manymolecules configured as a monolayer on elec-trode surfaces by either self- or directed-as-sembly. Recent work has pointed to a strongrelationship between the details of molecularorganization (i.e. tilt, morphology, etc.) and the

MEETING REPORTS

SYNCHROTRON RADIATION NEWS, Vol. 15, No. 6, 2002 3

Figure 1: At the outdoor CHESS banquet: SolGruner (CHESS director) and his wife Rose-marie Parker. In the background, Jun Wang andRong Huang, both of Cornell.

Figure 2: Gunter Grossmann of Daresbury Lab-oratory speaking about SAXS for macromolecu-lar studies.

Figure 3: Richard Gillilan and Michael Love,both of MacCHESS, discussing a crystallographyposter.

Figure 4: Andy Broadbent (Oxford Danfysik)and Alan Pauling (Cornell) discussing ion cham-bers at the vendor’s booth.

operating parameters of the devices. Synchro-tron radiation is a highly desirable tool forcharacterizing the structure and organizationof these films.

Brian McClain (Harvard) presented thecrystal structure of the rotavirus double-lay-ered particle at 5.5 Å resolution (soon to be ex-tended to 3.8 Å). The particle has an icosahe-dral shape, with 60-fold symmetry, and a totalmolecular weight of about 55 million Daltons,one of the largest high-resolution structuresever determined. McClain and co-workers arealso determining the structure of the triple-layered rotavirus particle, which is the intactform; the outer layer is stripped off when thevirus infects a cell. Rotaviruses include human

pathogens and are a leading cause of diarrheaand death due to dehydration in the ThirdWorld. A vaccine has been developed, but isassociated with adverse reactions when used ininfants. Determination of the double- andtriple-layered virus structures will illuminatethe method of infection by rotavirus and maylead to the development of a better vaccine.

Paul Urayama (Dartmouth) spoke aboutprobing protein substrates using high-pressureX-ray crystallography. Pressures in the rangeencountered in the biosphere are known tohave myriad effects on proteins, but in mostcases the molecular basis of these effects is notunderstood. Urayama and coworkers devel-oped methods to perform protein crystallogra-

phy at up to 2 kbar and then examined the ef-fects of pressure on conformational substatesin myoglobin. It was shown that crystallo-graphic pressure studies can be used to under-stand the substates that occur upon ligandbinding. The methods developed by Urayamaand co-workers are relatively easy to use andgenerally applicable to other proteins. Theymay well catalyze the general study of the ef-fects of pressure on proteins.

Olivier Thomas (Marseilles) presented hislatest high-resolution X-ray diffraction studyof 15 to 100 Å ultra-thin Fe films on GaAs(001) substrates. Such thin films have interest-ing magnetic spin properties and may proveuseful for electronic and memory devices.Grazing-incidence reciprocal space mapsaround the (110) and (200) reflections of Fe,measured at CHESS F3 station, revealed un-usual anisotropy in the in-plane domain sizeand in the in-plane lattice strain in thin filmswith two distinct directions, along [110] and[1–10]. Such anisotropies and their depend-ence on film thickness indicate that an inter-facial magnetic effect is the only possible ex-planation for the uniaxial in-plane magneticanisotropy measured in this system. This resultresolves questions that have puzzled magneticthin-film researchers for more than 15 years.

Workshop on New Technology andInnovative Applications of Small Angle X-ray Scattering

SAXS is the second most commonly usedtechnique (after crystallography) at CHESS.The theme of the SAXS workshop was thedemonstration of new techniques in the studyof large-unit cell materials.

Dr. Adam Finnefrock (Penn) describedwork (in collaboration with the Wiesner andGruner groups at Cornell) that used SAXS todetermine the structure of novel nanoporousorganic-inorganic composites. These materialsare synthesized by using diblock copolymersas structure-directing agents. The copolymerphase is swollen by a small-molecule organo-metallic compound with a strong preferencefor one of the two polymers making up thecopolymer. This provides an effective means

MEETING REPORTS

Vol. 15, No. 6, 2002, SYNCHROTRON RADIATION NEWS4

Figure 5: Installation of a dual Quantum-4 detector system at F1 station by Bill Miller and otherMacCHESS staff members. The two detector assembly, designed by Mike Cook, is capable of inde-pendent rotation by up to 30 degrees, effectively producing a detector with a total (V-shaped) surfacearea of 380 x 190 mm.

of controlling the effective volume fraction ofone of the blocks in the copolymer and allowsfine tuning of the resultant phase. The resultantmaterials form beautiful three-dimensionallyperiodic structures of the “plumber’s night-mare” morphology. The materials can be py-rolized to remove the organic parts, leaving ananoporous metal oxide framework that isamorphous on atomic length scales and crys-talline on the >100 Å scale. These are promis-ing materials for applications ranging frombattery electrodes to filtration matrices [2].Finnefrock explained that the X-ray challengewas to determine the structure on the polycrys-talline samples, even though each randomlyoriented crystallite is uniquely deformed in adirection perpendicular to the plane of the thincast-polymer samples. In order to accomplishthis, Finnefrock had to invent new methods toanalyze and understand the diffraction fromstrained, polycrystalline samples.

Detlef Smilgies (CHESS) described theuse of Grazing Incidence SAXS (GISAXS) toprobe the structure of thin polymer andcopolymer films spin-coated onto silicon sub-strates. GISAXS is a very powerful and rela-tively easy to use method that is generally newto many in the polymer community. Using awide-bandpass multilayer beam at the CHESSD-1 beamline in combination with a CCD areadetector, Smilgies performed GISAXS studies

on: (1) the dependence of the orientation oflamellae formed by symmetric diblock copoly-mers on increasing molecular weight; (2) nano-porous copolymer films formed by UV degra-dation of one of the blocks; and (3) theformation of a lattice of regular silica spheresin a copolymer in which an organic phase isenriched in one of the polymer componentsand the polymer is successively removed bythermal degradation. Smilgies showed thatGISAXS can be obtained on low-contrast sys-tems and he demonstrated that both lateral andperpendicular information about the thin filmstructure can be obtained. Even time-resolvedstudies on a time scale of minutes were possi-ble and first results were presented on the dy-namics of a lamellar film when exposed to sol-vent vapor.

Sol Gruner provided a tutorial on tech-niques for time-resolved SAXS (TR-SAXS),using numerous examples from the work of hisgroup on polymers, solutions of biomolecules,lipid-water dispersions, and biomembranes.The theme of this talk was to present an outlineof the options and decisions that need to bemade to record TR-SAXS data in variousregimes of scattering strength and time-resolu-tion. Examples included when to use one-di-mensional vs. two-dimensional detectors,when multilayer optics are particularly useful,how various custom clocking modes of a CCDdetector can improve the signal strength andtime resolution of the diffraction patterns, andthe use of pixel X-ray detectors for microsec-ond time-resolved applications.

After lunch, the two workshops merged inorder to hear Gunter Grossmann (CLRC Dares-bury Lab) describe the use of SAXS for macro-molecular studies. Dr. Grossmann’s talk is fur-ther reported in the next workshop section ofHigh-Throughput Crystallography & Comple-mentary Methods.

The final speaker in the SAXS workshopwas Ken Finkelstein (CHESS), who describedthe use of anomalous scattering in SAXS. Hefirst summarized basic principles of the method,including how novel X-ray optics allow twobeams of slightly different X-ray energies tocross at the sample and then to be separately

collected with an area detector. By tuning thebeam energies to span a region just below theabsorption edge of a heavy atom in the sample,Finkelstein is able to measure very small dif-ference signals arising from those atoms. Hedescribed using this method to study the sizedistribution of platinum clusters in a zeolitecatalyst support, in collaboration with HarryBrumberger (now deceased), Douglas Hagr-man, and Jerry Goodisman from Syracuse. Healso described a study with Lois Pollack’sgroup (Cornell) on the condensation ofcounter-ion clouds around nucleotide poly-mers in solution.

Workshop on High-Throughput Crystallog-raphy and Complementary Methods

This year’s MacCHESS workshop fo-cused on a variety of methods and technolo-gies aimed at improving the overall throughputof X-ray crystallography. The opening speaker,Rob Thorne (Cornell), discussed his recentwork at CHESS on understanding why flash-cooled protein crystals tend to have high mo-saic spread. This phenomenon causes seriousproblems for viruses and other systems withlarge unit cells. The difference in thermal con-traction between amorphous ice and proteinresults in ice pockets within the lattice thatlead to the formation of microscopic domains.Thorne suggested that careful matching of theexpansion coefficient of the cryoprotectantwith that of the protein lattice could lead tobetter results. X-ray topography was also usedto examine the process of crystal annealing.Microdomains caused by flash cooling can beannealed by warming the crystal to just abovethe water glass transition (150K). Thorne de-scribed a device invented in his lab that canwarm and cool the cryostream rapidly for thispurpose [3].

The second talk of the morning was givenby Zbigniew Dauter (NCI and Brookhaven Na-tional Laboratory) on the use of Single-wave-length Anomalous Dispersion (SAD) for phas-ing protein diffraction data. Anomalousscatterers can either occur naturally in the pro-tein (sulfur, phosphorous or transition metals)or can be introduced (selenium or certain

MEETING REPORTS

SYNCHROTRON RADIATION NEWS, Vol. 15, No. 6, 2002 5

Figure 6: Reflectivity curve from the Osmic low-contrast multilayer with 500 bi-layers and d =31.5 Å. The width of the curve is 14.6 arc sec,bandwidth ∆E/E = 0.29%. Data taken atCHESS A2 station.

halides). Recent advances in both hardwareand software now allow structures to be solvedon a single (peak) wavelength. High multi-plicity in measurements, however, is a key fac-tor for success. Dauter recommended collect-ing peak data first and attempting to solve thestructure on the single wavelength while thenext MAD wavelength is still being collected(the so-called 1-1/2 wavelength method). Re-processing of historical data sets indicates that,in many cases, MAD is not needed. Themethod is well suited for use in high-through-put environments.

Martine Cadene (The Rockefeller Univer-sity) introduced the many uses of mass spec-trometry in protein crystallography. One of theoutstanding barriers to high-throughput crys-tallography is obtaining crystals. When a pro-tein fails to crystallize, it is often possible do apartial proteolysis to locate structurally com-

pact domains. Matrix-Assisted Laser Desorp-tion Ionization (MALDI) is an excellent toolfor following the progress of proteolytic diges-tions. Proteins of up to 50,000 Daltons can beobserved. Cadene presented a special thinlayer method for sample spot preparation thatenhances sensitivity [4]. MALDI mass spec-trometry can also easily distinguish between na-tive protein and selenomethionine derivatives.

Recent innovations in the reconstructionof biomolecular structures from small-anglesolution scattering were discussed by J. GunterGrossmann (CLRC Daresbury Laboratory) ina joint session between the macromolecularand SAXS workshops. X-ray scattering pro-files in the 50 to 8 Å range yield informationabout the overall shape of a protein. Small vol-umes of protein solutions are used at concen-trations similar to conventional crystallogra-phy (10 mg/ml or less). Grossmann presentedexamples with sufficient resolution to observesome conformational changes in proteins dur-ing complexation (nitrogenase and α-crusta-cyanin). Molecular shapes can be reconstructedusing spherical harmonic expansions or beadmodels, the latter being capable of resolvingsome internal structure. Low-resolution mo-lecular shapes have also been used by Gross-mann and Hao to help phase diffraction data.

Art Weaver (AJW Research) showcasedthe new Linux supercomputer he designed incollaboration with Frank Labonte (CHESS andMacCHESS). The 31 diskless dual-processorAthlon nodes are interconnected with aMyrinet 2 Gbit/sec low latency optical switchfor high-speed distributed parallel computing.The nodes run the RedHat 7.1 SMP Linuxkernel. Parallel tests were performed on SnB(Shake-and-Bake phasing), MPI_FSEARCH(molecular replacement) and WebXDS.Weaver phased a selenomethionine epimerasecontaining 70 Se sites in 39 minutes, a task thattook 17 hours on two processors. This singlerack-mounted system, nicknamed Sirius,weighs in at more than 450 Kg (1000 lbs). Thepower consumption is about 8 kW, with a cool-ing requirement of more than 27,000 BTU/hr.Weaver warned future cluster builders to al-ways estimate power consumption and coolingrequirements, and to seriously consider low-

power alternatives such as Green Destiny de-veloped by Los Alamos National Laboratory.Complete details on Sirius, including bench-marks, can be found on the web at staff.chess.cornell.edu/~weaver/sirius.html.

Poster presenters competed for the bestposters in the categories of best science, bestinstrumentation and best graphic design.Members of the workshop executive committeeevaluated the posters during the two meetingdays and presented awards on the final after-noon. The awards for best science and bestgraphic design went to Peter Busch, FriedrichKremer, Christine M. Papadakis (Leipzig),Dorthe Posselt (Roskilde) and Detlef Smilgies(CHESS) for a poster entitled “An X-ray Re-flectivity and GISAXS Study of the Lamellarorientation in Thin Diblock Copolymer films.”Best instrumentation went to: “Pixel Array De-tector for Microsecond Imaging” by Sol Gruner,Mark Tate, Matt Renzi, Alper Ercan of CornellUniversity; Sandor Barna and Giusseppe Rossiof Micron Technologies, Inc.; Eric Eikenberry,Paul Scherrer Institute; Bob Wixted; DonBilderback and Ernie Fontes of CHESS; JinWang, Chris Powell, Andrew MacPhee, YongYue, and Suresh Narayanan, Advanced PhotonSource. Matt Renzi and Alper Ercan receivedthe award for the development team. �

DONALD BILDERBACK, SOL GRUNER, AND RICHARD GILLILAN

Cornell University

References1. D. Bilderback, I. Bazarov, K. Finkelstein,

S. Gruner, G. Krafft, L. Merminga, H. Pa-damsee, Q. Shen, C. Sinclair, M. Tigner, andR. Talman, Synchrotron Radiation News,14, May/June 2001, 12–21. Additional ERLinformation can be found posted at http://erl.chess.cornell.edu/.

2. A. Finnefrock, R. Ulrich, A. Du Chesne, C.Honeker, K. Schumacher, K. Unger, S.Gruner and U. Wiesner, AngewandteChemie Int. Ed. 40 (2001) 1208–1211.

3. S. Kriminski, C. Caylor, M. Nonato, K.Finkelstein and R. Thorne, Acta Cryst. D58459 (2002).

4. M. Cadene and B. T. Chait, Anal. Chem. 72,(2000) 5655–5658.

MEETING REPORTS

Vol. 15, No. 6, 2002, SYNCHROTRON RADIATION NEWS6

#4

Applied Geomechanics

1/6 pg. B&W

Repeat SRN 15.5