Primary research categories of respondents:
| Research Category | Number of Investigators |
| Macromolecular crystallography | XTAL (201 investigators or 76.7% of respondents) |
| Scattering from noncrystalline materials | SNM (26 investigators or 9.9% of respondents) |
| X-ray spectroscopy | XAS (24 investigators or 9.1% of respondents) |
| X-ray microscopy | IMG (11 investigators or 4.2% of respondents) |
| Other | (6 investigators or 2.3% of respondents) |
| No primary category | (8 investigators or 3.1% of respondents) |
Total number of responses was 262. Of these, 11 indicated more than one primary category and 8 indicated no primary category. Primary category was assigned as the most frequent use indicated of synchrotrons for experiments (see Table A-2). Those that indicated equal frequency of use in more than one category were included in the analysis for each of those categories. Of those indicating Other, the descriptions were: interferometry; infrared radiochemistry; x-ray standing wave; and detector development.
Table A-1. Work Environment of Structural Biologists
| Current Employer | Number of Investigators |
| University | 187 (71.4%) |
| Government Laboratory | 34 (12.9%) |
| Other (private and nonprofit) | 18 (6.9%) |
| Industry | 23 (8.8%) |
| Total | 262 |
Table A-2. Use of Synchrotrons for Certain Experiments
| Experiment Symbol | Major Use | Occasional | Once Only | Never | |
| Macromolecular crystallography: | |||||
| XTAL | Monochromatic | 109 | 68 | 16 | 69 |
| XTAL | MAD Phasing | 29 | 36 | 25 | 172 |
| XTAL | Laue | 4 | 10 | 19 | 229 |
| Scattering from noncrystalline materials: | |||||
| SNM | Static | 21 | 14 | 8 | 219 |
| SNM | Time-resolved | 12 | 10 | 2 | 238 |
| X-ray Spectroscopy: | |||||
| XAS | Static | 21 | 10 | 6 | 225 |
| XAS | Time-resolved | 1 | 7 | 2 | 252 |
| X-ray Imaging/ Microscopy
IMG |
9 | 5 | 0 | 248 | |
| Other | 5 | 1 | 0 | 256 | |
The results for Table A-2 were obtained by adding the number of people who responded to each type of experiment for each of four possible answers.
Table A-3. Correlation of Size of Research Group with Number of Years
as an Independent Investigator
| First Year as Independent Investigator | Number of Investigators | Number of Staff | Average Size of Research Group | Total Number of Researchers | Average Anticipated 5-Year Change in Size |
| 1992-97 | 75 | 375 | 6 | 450 | +1.9 |
| 1987-91 | 50 | 343 | 7.9 | 393 | +1.2 |
| 1982-86 | 33 | 223 | 7.8 | 256 | +1.5 |
| 1977-81 | 27 | 187 | 7.9 | 214 | +0.8 |
| Before 1977 | 77 | 654 | 9.5 | 731 | -0.5 |
| Total | 262 | 1782 | 2044 |
The results for Table A-3 were obtained by adding the number of investigators who had worked as independent investigators for periods of 5 years at a time. The total number of researchers was obtained by adding the number of postdocs, graduate students, and support staff to the number of investigators for groups of 5 years at a time. This number was divided by the number of independent investigators to find the average size of the research group for each of the periods of time. To find the average anticipated size of research groups in 5 years, that number was added to the total number of investigators, averaged, and the difference between the existing number and the anticipated number was figured.
Table A-4. Correlation of Scientific Discipline with Number of Years
as an Independent Investigator
Number of Investigators
| First Year as an Independent Investigator | XTAL | SNM | XAS | IMG | Other | None | Total |
| 1992-97 | 63 | 2 | 3 | 3 | 2 | 3 | 76 |
| 1987-91 | 43 | 1 | 3 | 3 | 2 | 0 | 52 |
| 1982-86 | 23 | 5 | 5 | 1 | 1 | 0 | 35 |
| 1977-81 | 18 | 4 | 4 | 3 | 1 | 0 | 30 |
| Before 1977 | 54 | 14 | 9 | 1 | 0 | 5 | 83 |
| Total | 201 | 26 | 24 | 11 | 6 | 8 | 276 |
Table A-5. Level and Sources of Research Support
| Annual Research Support | Number of Investigators | Source of Research Support | Number of Investigators | |
| $1K-50K | 37 | NIH | 180 | |
| $50K-150K | 80 | Foundation | 66 | |
| $150K-250K | 45 | NSF | 63 | |
| >$250K | 65 | Industry | 57 | |
| unspecified | 7 | DOE | 40 | |
| No external support | 28 | Other U.S. government | 24 | |
| Canada | 15 | |||
| Investigator's Institution | 14 | |||
| Other International | 6 | |||
| State | 2 | |||
| Other Unspecified | 4 |
Table A-6. Biological Use of Synchrotron Radiation Facilities 1994-1996
Total Days Each Year Reported by Users
| Year | SSRL | CHESS | NSLS | ALS | APS | SRS | LURE | DESY | PhFac | ESRF | Total |
| 1994 | 439 | 277 | 883 | 70 | 0 | 24 | 45 | 23 | 75 | 33 | 1869 |
| 1995 | 547 | 275 | 980 | 280 | 2 | 15 | 55 | 37 | 45 | 48 | 2284 |
| 1996 | 671 | 369 | 1194 | 345 | 110 | 9 | 48 | 53 | 29 | 88 | 2916 |
These results were obtained by adding the number of days each facility was used by year.
Table A-7. Factors Limiting Use of Synchrotron Radiation by Scientific Discipline
A. Too much time between application for beam time and experiment.
B. Can't readily get synchrotron beam time.
C. Insufficient research support to enable travel to the synchrotron.
D. Burdensome requirements for beam time proposals.
E. Key instrumentation for experiment unavailable at synchrotron facility.
F. Insufficient user support at synchrotron facility.
G. Don't need it for my research.
H. Other
I. Too much radiation damage to samples.
J. Sample problems
Number of Respondents
| Factor | XTAL | SNM | XAS | IMG | None | Other | Total (% of respondents) |
| A | 121 | 8 | 4 | 2 | 1 | 1 | 137 (52.3) |
| B | 112 | 6 | 3 | 6 | 1 | 1 | 129 (49.2) |
| C | 44 | 5 | 7 | 0 | 2 | 2 | 60 (22.9) |
| D | 41 | 4 | 4 | 1 | 2 | 1 | 52 (19.8) |
| E | 16 | 4 | 1 | 2 | 1 | 2 | 24 (9.2) |
| F | 16 | 3 | 0 | 1 | 1 | 1 | 22 (8.4) |
| G | 15 | 1 | 0 | 0 | 3 | 2 | 21 (8.0) |
| H | 9 | 2 | 4 | 1 | 0 | 2 | 18 (6.9) |
| I | 3 | 4 | 1 | 1 | 1 | 2 | 11 (4.2) |
| J | 6 | 0 | 0 | 0 | 0 | 0 | 6 (2.2) |
The results for Table A-7 were obtained by adding the number of respondents to each factor limiting use of the synchrotron facilities by each category of investigation. Description of other factors limiting use were: too busy building beamlines; other demands on researcher's time; enough time for data analysis; we have our own line; convenience of staying home; personnel available; analysis time is rate limiting; proprietary research projects; usual experimental limitations; and small group/large time blocks.
Table A-8. Importance of Synchrotron Radiation to the
Investigator's Future Research Plans
A. Critical
B. Very Important
C. Moderately Important
D. Unimportant
| Factors | XTAL | SNM | XAS | IMG | Other | None | Total (% of respondents) |
| A | 127 | 14 | 16 | 10 | 3 | 3 | 173 (63) |
| B | 56 | 6 | 5 | 1 | 2 | 0 | 70 (25) |
| C | 18 | 6 | 2 | 0 | 1 | 1 | 28 (10) |
| D | 0 | 0 | 1 | 0 | 0 | 4 | 5 (2) |
The results for Table A-8 were found by adding the number of responses of each type of investigator by each level of importance of synchrotron radiation in the future.
Table A-9. Relative Importance of Various Features of Synchrotron Radiation Facilities
A. Fast, efficient X-ray detectors
B. High brilliance/intensity/flux
C. Detectors with high spatial resolution
D. Computing and network services
E. Repeated access for long-term projects
F. High energy resolution
G. User-friendly environment
H. Helpful, readily accessible support staff
I. Rapid access for single experiments or feasibility studies
J. User training
K. On-site data processing
L. Good communication, e.g., user group, Web site, documentation
M. Good ancillary facilities, e.g., cold room, biochemistry lab, stock room
N. Intellectually stimulating environment
O. Good housing and convenient services
P. Other
| Feature | Essential | Important | Helpful | Occasionally helpful | Unimportant | No Answer |
| A | 205 | 38 | 7 | 1 | 0 | 11 |
| B | 191 | 55 | 7 | 1 | 0 | 8 |
| C | 157 | 53 | 17 | 12 | 8 | 15 |
| D | 155 | 70 | 18 | 5 | 0 | 14 |
| E | 146 | 76 | 20 | 4 | 3 | 13 |
| F | 139 | 61 | 25 | 9 | 9 | 19 |
| G | 134 | 82 | 36 | 1 | 0 | 9 |
| H | 134 | 89 | 28 | 3 | 0 | 8 |
| I | 130 | 84 | 27 | 6 | 2 | 13 |
| J | 113 | 79 | 44 | 7 | 7 | 12 |
| K | 109 | 85 | 45 | 12 | 0 | 11 |
| L | 84 | 76 | 67 | 20 | 2 | 13 |
| M | 82 | 92 | 55 | 19 | 2 | 12 |
| N | 52 | 48 | 101 | 28 | 19 | 14 |
| O | 49 | 90 | 88 | 13 | 9 | 13 |
| P | 10 | 2 | 0 | 0 | 1 | 249 |
The results for table A-9 were obtained by adding the number of each of five possible responses (essential, important, helpful, occasionally helpful, or unimportant) or no response by each feature of the synchrotron facilities. Descriptions of Other were: stable beam, stable optics out; time slicing; coding system; on-site machine shop; and truly optimal MAD beamlines.
Table A-10. Future Uses of Synchrotron Radiation by Scientific Discipline
A. Crystal structure determination by monochromatic techniques
B. Crystal structure determination by multiwavelength anomalous diffraction (MAD)
C. Determination of multiple crystal structures for proteins provided by site-directed
mutagenesis, or as part of drug/ligand studies
D. Time-resolved structure analysis
E. Non-crystalline diffraction
F. Solution scattering of biomolecules and their complexes
G. X-ray spectroscopy
H. Direct imaging by X-ray microscopy
I. Other
| Use | XTAL | SNM | XAS | IMG | Other | None | Total |
| A | 151 | 6 | 3 | 2 | 1 | 0 | 163 |
| B | 101 | 3 | 1 | 2 | 0 | 0 | 107 |
| C | 95 | 2 | 1 | 2 | 0 | 0 | 100 |
| D | 10 | 11 | 1 | 1 | 0 | 0 | 23 |
| E | 4 | 10 | 1 | 1 | 0 | 0 | 16 |
| F | 2 | 10 | 3 | 1 | 0 | 0 | 16 |
| G | 3 | 4 | 20 | 3 | 1 | 0 | 31 |
| H | 1 | 3 | 2 | 9 | 0 | 0 | 15 |
| I | 3 | 2 | 2 | 1 | 3 | 0 | 11 |
The results for Table A-10 were obtained by adding the number of responses of 1 (very frequently) or 2 (regular) to each type of future use by each scientific discipline. The total use for some items is greater than the number of respondents because some investigators indicated use in more than one scientific discipline. Descriptions of Other were: XIFS, interferometry; resonance x-ray diffraction; infrared, radiochemistry; topography and mosaicity; development of x-ray optics; instrumentation development; and detector software development.
Table A-11 and A-12. Collaborations
A total of 151 researchers collaborated with other independent investigators who do not have expertise in synchrotron science.
Table A-11. Collaborations
| 1994 | 1995 | 1996 | |
| Number of responses | 95 | 109 | 125 |
| Number of collaborations | 293 | 332 | 487 |
Table A-12. Collaborations by Discipline (Number of respondents in parenthesis)
| Discipline | 1994 | 1995 | 1996 |
| XTAL | 127 (62) | 158 (76) | 258 (901) |
| SNM | 41 (8) | 38 (7) | 78 (9) |
| XAS | 106 (16) | 108 (17) | 118 (16) |
| IMG | 16 (8) | 25 (8) | 30 (9) |
| Other | 3 (1) | 3 (1) | 3 (1) |
1One additional researcher reported 230 collaborations!
Table A-13. Publications
| Number of Publications |
| First Year as an Independent Investigator | 1994 | 1995 | 1996 |
| 1992-97 | 32 | 52 | 66 |
| 1987-91 | 68 | 75 | 95 |
| 1982-86 | 43 | 53 | 64 |
| 1977-81 | 47 | 57 | 53 |
| Before 1977 | 109 | 138 | 141 |
| Total | 299 | 375 | 419 |
This survey was administered by Sheryl Martin and Laura Yust of the Human Genome Management Information System at Oak Ridge National Laboratory.