Search Results

Advanced search parameters have been applied.
open access

Closing remarks: A prespective from the advanced synchrotron light source conference on the vacuum design of advanced and compact synchrotron light sources

Description: The scope and breadth of the conference are reviewed from the personal perspective of the author. The need for additional desorption data and more rapid development and testing of proptotype vacuum system components for the next generation facilities are highlighted.
Date: January 1, 1988
Creator: Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

In-situ reactive of x-ray optics by glow discharge

Description: We have developed a method of in-situ reactive glow discharge cleaning of x-ray optical surfaces which is capable of complete removal of carbon contamination. Our work is the first to successfully clean an entire optical system in-situ and characterize its performance at short wavelengths (as low as 10 /angstrom/). The apparatus required is quite simple and can easily be fitted to most existing UHV (ultra high vacuum) mirror boxes of monochromators. The advantages of this technique over previou… more
Date: January 1, 1987
Creator: Johnson, E. D. & Garrett, R. F.
Partner: UNT Libraries Government Documents Department
open access

In-situ reactive glow discharge cleaning of NSLS distributed ion pumps

Description: Based on our experience with the in-situ cleaning of optical systems by reactive r.f. glow discharges and the conditioning and preparation of distributed ion pump (DIP) elements, we have sought to develop strategies for recovering from severe vacuum accidents by restoring DIP elements of storage rings such as those at the NSLS in-situ. In this paper we will describe a series of experiments conducted in a test apparatus to condition a so called ''egg-crate'' DIP in-situ, (this older type element… more
Date: January 1, 1988
Creator: Johnson, E. D. & Chou, T. S.
Partner: UNT Libraries Government Documents Department
open access

Briefing paper for the proposed ultraviolet free-electron laser (UV- FEL) facility at Brookhaven National Laboratory

Description: The proposed Brookhaven National Laboratory ultraviolet free-electron laser (UV-FEL) user facility will provide picosecond and sub-picosecond pulses of coherent ultraviolet radiation for wavelengths from 300 to 75 nm. Pulse width will be variable from about 7 ps to {approx} 200 fs, with repetition rates as high as l0{sup 4}Hz, single pulse energies > 1 NJ and hence peak pulse power > 200 MW and average beam power > 10 W. The facility will be capable of ``pump-probe`` experiments utilizing the F… more
Date: July 15, 1992
Creator: Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

Concepts for UV-FEL optics

Description: Brookhaven National Laboratory has developed a design for an ultra-violet free electron laser facility utilizing a seeded amplifier approach. Since the accelerator is a single pass device, resonator and outcoupler mirrors which are a difficult aspect of oscillator FEL designs are not required. The result is a source of high peak power VUV radiation with the mode structure, bandwidth and frequency stability of the input seed laser. The accelerator provides pulses of radiation at up to 10 kHz, so… more
Date: November 1, 1993
Creator: Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

Scientific opportunities for FEL amplifier based VUV and X-ray research

Description: It has become increasingly clear to a wide cross section of the synchrotron radiation research community that FELs will be the cornerstone of Fourth Generation Radiation Sources. Through the coherent generation of radiation, they provide as much as 12 orders of magnitude increase in peak power over the third generation storage ring machines of today. Facilities have been proposed which will extend the operating wavelength of these devices well beyond the reach of existing solid state laser tech… more
Date: December 31, 1994
Creator: Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

Briefing paper for the proposed ultraviolet free-electron laser (UV- FEL) facility at Brookhaven National Laboratory

Description: The proposed Brookhaven National Laboratory ultraviolet free-electron laser (UV-FEL) user facility will provide picosecond and sub-picosecond pulses of coherent ultraviolet radiation for wavelengths from 300 to 75 nm. Pulse width will be variable from about 7 ps to {approx} 200 fs, with repetition rates as high as l0{sup 4}Hz, single pulse energies > 1 NJ and hence peak pulse power > 200 MW and average beam power > 10 W. The facility will be capable of pump-probe'' experiments utilizing the FEL… more
Date: July 15, 1992
Creator: Johnson, E.D. (comp.)
Partner: UNT Libraries Government Documents Department
open access

Ultraviolet free-electron laser (uv FEL) facility at Brookhaven National Laboratory

Description: The proposal for a Ultraviolet Free-Electron Laser Facility UV-FEL grew from the realization that neither existing lasers or synchrotrons, nor the third generation synchrotron radiation sources now under construction address all of the needs of scientists interested in the ultraviolet region of the spectrum, particularly with respect to the combination of continuous wavelength selection, high peak power and short pulse duration. Several workshops have been held at BNL and elsewhere which explor… more
Date: December 31, 1992
Creator: Johnson, E. D. & Sutherland, J. C.
Partner: UNT Libraries Government Documents Department
open access

Ultraviolet free-electron laser (uv FEL) facility at Brookhaven National Laboratory

Description: The proposal for a Ultraviolet Free-Electron Laser Facility UV-FEL grew from the realization that neither existing lasers or synchrotrons, nor the third generation synchrotron radiation sources now under construction address all of the needs of scientists interested in the ultraviolet region of the spectrum, particularly with respect to the combination of continuous wavelength selection, high peak power and short pulse duration. Several workshops have been held at BNL and elsewhere which explor… more
Date: January 1, 1992
Creator: Johnson, E. D. & Sutherland, J. C.
Partner: UNT Libraries Government Documents Department
open access

Report from the NSLS workshop: Sources and applications of high intensity uv-vuv light

Description: A workshop was held to evaluate sources and applications of high intensity, ultra violet (UV) radiation for biological, chemical, and materials sciences. The proposed sources are a UV free electron laser (FEL) driven by a high brightness linac and undulators in long, straight sections of a specially designed low energy (400 MeV) storage ring. These two distinct types of sources will provide a broad range of scientific opportunities that were discussed in detail during the workshop.
Date: December 31, 1990
Creator: Johnson, E. D. & Hastings, J. B.
Partner: UNT Libraries Government Documents Department
open access

Periscope Pop-in Beam Monitor.

Description: We have built monitors for use as beam diagnostics in the narrow gap of an undulator for an FEL experiment. They utilize an intercepting screen of doped YAG scintillating crystal to make light that is imaged through a periscope by conventional video equipment. The absolute position can be ascertained by comparing the electron beam position with the position of a He:Ne laser that is observed by this pop-in monitor. The optical properties of the periscope and the mechanical arrangement of the sys… more
Date: May 7, 1998
Creator: Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

Kinematic mounting systems for NSLS beamlines and experiments

Description: Methods for kinematically mounting equipment are well established, but applications at synchrotron radiation facilities are subject to constraints not always encountered in more traditional laboratory settings. Independent position adjustment of beamline components can have significant benefits in terms of minimizing time spent aligning, and maximizing time spent acquiring data. In this paper, we use examples taken from beamlines at the NSLS to demonstrate approaches for optimization of the rep… more
Date: January 1, 1991
Creator: Oversluizen, T.; Stoeber, W. & Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

Report from the NSLS workshop: Sources and applications of high intensity uv-vuv light

Description: A workshop was held to evaluate sources and applications of high intensity, ultra violet (UV) radiation for biological, chemical, and materials sciences. The proposed sources are a UV free electron laser (FEL) driven by a high brightness linac and undulators in long, straight sections of a specially designed low energy (400 MeV) storage ring. These two distinct types of sources will provide a broad range of scientific opportunities that were discussed in detail during the workshop.
Date: January 1, 1990
Creator: Johnson, E. D. & Hastings, J. B. (eds.)
Partner: UNT Libraries Government Documents Department
open access

NSLS source development laboratory

Description: The National Synchrotron Light Source (NSLS) has initiated an ambitious project to develop fourth generation radiation sources. To achieve this goal, the Source Development Laboratory (SDL) builds on the experience gained at the NSLS, and at the highly successful BNL Accelerator Test Facility. The SDL accelerator system will consist of a high brightness short pulse linac, a station for coherent synchrotron and transition radiation experiments, a short bunch storage ring, and an ultra-violet fre… more
Date: September 1, 1995
Creator: Ben-Zvi, Ilan; Blum, E. & Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

Beamlines at synchrotron radiation facilities: The link between the user and the machine

Description: At this point in time the literature is full of excellent review articles which describe the operating principles of optical systems for utilizing the unique radiation provided by synchrotron storage rings. In general, the perspective provided by this body of work is that of the end user-experimenter cum optics designer. Nominal design specifications of the accelerator are usually assumed, and the impact of operation in a performance envelope which may represent either degraded or enhanced mach… more
Date: December 1, 1991
Creator: Johnson, E. D.; Hulbert, S. L. & Berman, L. E.
Partner: UNT Libraries Government Documents Department
open access

Recent advances in soft x-ray scattering instrumentation at the national synchrotron light source

Description: For the study of condensed matter systems x-ray scattering experiments are often the best choice as they have several desirable features including complete conservation of momentum in the incident and detected particles, well characterized initial and final electronic states, and insensitivity of photon transport to external electric and magnetic fields (as compared to photoelectrons for example). To extend these techniques to the soft x-ray region ({Dirac h}v < 1keV) the lack of suitable detec… more
Date: January 1, 1991
Creator: Johnson, E. D.; Kao, Chi-Chang & Hastings, J. B.
Partner: UNT Libraries Government Documents Department
open access

Beamlines at synchrotron radiation facilities: The link between the user and the machine

Description: At this point in time the literature is full of excellent review articles which describe the operating principles of optical systems for utilizing the unique radiation provided by synchrotron storage rings. In general, the perspective provided by this body of work is that of the end user-experimenter cum optics designer. Nominal design specifications of the accelerator are usually assumed, and the impact of operation in a performance envelope which may represent either degraded or enhanced mach… more
Date: December 1, 1991
Creator: Johnson, E. D.; Hulbert, S. L. & Berman, L. E.
Partner: UNT Libraries Government Documents Department
open access

Supporting document for the historical tank content estimate for B Tank Farm

Description: This document provides historical evaluations of the radioactive mixed wastes stored in the Hanford Site 200-East Area underground single-shell tanks (SSTs). A Historical Tank Content Estimate has been developed by reviewing the process histories, waste transfer data, and available physical and chemical characterization data from various Department of Energy (DOE) and Department of Defense (DOD) contractors. The historical data will supplement information gathered from in-tank core sampling act… more
Date: June 1, 1994
Creator: Brevick, C. H.; Gaddis, L. A. & Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

Supporting document for the SW Quadrant Historical Tank Content Estimate for U-Tank Farm

Description: This Supporting Document provides historical characterization information gathered on U-Tank Farm, such as historical waste transfer and level data, tank physical information, temperature data, sampling data, and drywell and liquid observation well data for Historical Tank Content Estimate of the SW Quadrant at the Hanford 200 West Area.
Date: June 1, 1994
Creator: Brevick, C. H.; Gaddis, L. A. & Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

Supporting Document for the SW Quadrant Historical Tank Content Estimate for SX-Tank Farm

Description: This Supporting Document provides historical characterization information gathered on SX-Tank Farm, such as historical waste transfer and level data, tank physical information, temperature data, sampling data, and drywell and liquid observation well data for Historical Tank Content Estimate of the SW Quadrant at the Hanford 200 West Area.
Date: June 1994
Creator: Brevick, C. H.; Gaddis, L. A. & Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

A hard x-ray prototype production exposure station at NSLS

Description: Exposures conducted at the NSLS R and D beamline (X-27B) for High Aspect Ratio Precision Manufacture have proven sufficiently successful that the authors are constructing a dedicated hard x-ray exposure beamline. The new beamline (X-14B) provides an exposure field {approximately} 120 mm wide, three times larger than that of X-27B. The scanner is based on the hydraulic system from the X-27B program. It is optimized for planar exposures and takes advantage of the full 525 mm stroke available. Exp… more
Date: July 1, 1997
Creator: Johnson, E. D. & Milne, J. C.
Partner: UNT Libraries Government Documents Department
open access

Tank waste source term inventory validation. Volume 1. Letter report

Description: The sample data for selection of 11 radionuclides and 24 chemical analytes were extracted from six separate sample data sets, were arranged in a tabular format and were plotted on scatter plots for all of the 149 single-shell tanks, the 24 double-shell tanks and the four aging waste tanks. The solid and liquid sample data was placed in separate tables and plots. The sample data and plots were compiled from the following data sets: characterization raw sample data, recent core samples, D. Braun … more
Date: April 28, 1995
Creator: Brevick, C. H.; Gaddis, L. A. & Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

High speed hydraulic scanner for deep x-ray lithography

Description: From their research and development in hard x-ray lithography, the authors have found that the conventional leadscrew driven scanner stages do not provide adequate scan speed or travel. These considerations have led the authors to develop a scanning system based on a long stroke hydraulic drive with 635 mm of travel and closed loop feedback to position the stage to better than 100 micrometers. The control of the device is through a PC with a custom LabView interface coupled to simple x-ray beam… more
Date: July 1, 1997
Creator: Milne, J. C. & Johnson, E. D.
Partner: UNT Libraries Government Documents Department
open access

The Plasma Window: A Windowless High Pressure Vacuum Interface for Various Accelerator Applications.

Description: The Plasma Window is a stabilized plasma arc used as an interface between accelerator vacuum and pressurized targets. There is no solid material introduced into the beam and thus it is also capable of transmitting particle beams and electromagnetic radiation with low loss and of sustaining high beam currents without damage. Measurements on a prototype system with a 3 mm diameter opening have shown that pressure differences of more than 2.5 atmospheres can be sustained with an input pressure of … more
Date: March 29, 1999
Creator: Hershcovitch, A. I.; Johnson, E. D. & Lanza, R. C.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen