Search PubMed⌕ Search

Biomedical subjects

E Gluskin

Publications and source records attributed to E Gluskin.

7 recordsLinked to original sources
PubMed2001

Exponential gain and saturation of a self-amplified spontaneous emission free-electron laser.

Self-amplified spontaneous emission in a free-electron laser has been proposed for the generation of very high brightness coherent x-rays. This process involves passing a high-energy, high-charge, short-pulse, low-energy-spread, and low-emittance electron beam through the periodic magnetic field of a long series of high-quality undulator magnets. The radiation produced grows exponentially in intensity until it reaches a saturation point. We report on the demonstration of self-amplified spontaneous emission gain, exponential growth, and saturation at visible (530 nanometers) and ultraviolet (385 nanometers) wavelengths. Good agreement between theory and simulation indicates that scaling to much shorter wavelengths may be possible. These results confirm the physics behind the self-amplified spontaneous emission process and forward the development of an operational x-ray free-electron laser.

Journal Article↗
PubMed2000

High-gain harmonic-generation free-electron laser

A high-gain harmonic-generation free-electron laser is demonstrated. Our approach uses a laser-seeded free-electron laser to produce amplified, longitudinally coherent, Fourier transform-limited output at a harmonic of the seed laser. A seed carbon dioxide laser at a wavelength of 10.6 micrometers produced saturated, amplified free-electron laser output at the second-harmonic wavelength, 5.3 micrometers. The experiment verifies the theoretical foundation for the technique and prepares the way for the application of this technique in the vacuum ultraviolet region of the spectrum, with the ultimate goal of extending the approach to provide an intense, highly coherent source of hard x-rays.

Journal Article↗
PubMed2000

Observation of self-amplified spontaneous emission and exponential growth at 530 nm

Experimental evidence for self-amplified spontaneous emission (SASE) at 530 nm is reported. The measurements were made at the low-energy undulator test line facility at the Advanced Photon Source, Argonne National Laboratory. The experimental setup and details of the experimental results are presented, as well as preliminary analysis. This experiment extends to shorter wavelengths the operational knowledge of a linac-based SASE free-electron laser and explicitly shows the predicted exponential growth in intensity of the optical pulse as a function of length along the undulator.

Journal Article↗
PubMed1998

APS Insertion Devices: Recent Developments and Results.

The Advanced Photon Source (APS) now has a total of 23 insertion devices (IDs). Over two-thirds of them are installed on the storage ring. The installed devices include 18, 27 and 55 mm-period undulators; an 85 mm-period wiggler; a 16 cm-period elliptical multipole wiggler; and many 33 mm-period undulators. Most of the IDs occupy storage-ring straight sections equipped with 8 mm vertical-aperture vacuum chambers. All of the IDs were measured magnetically at the APS and, in most cases, underwent a final magnetic tuning in order to minimize variation in the various integrals of the field through the ID over the full gap range. Special shimming techniques to correct magnetic field parameters in appropriate gap-dependent ways were developed and applied. Measurements of the closed-orbit distortion as a function of the ID gap variation have been completed, and results are in a good agreement with magnetic measurements. Spectral diagnostics of the ID radiation, including measurements of the absolute spectral flux, brilliance and polarization, show excellent agreement between calculated and measured results. Studies of the sensitivity of IDs to radiation exposure and measurements of the dose rate received by the IDs are in progress.

Journal Article↗
PubMed1997

Measurements of emittance and absolute spectral flux of the PETRA undulator at DESY Hamburg.

The first synchrotron radiation beamline using a 4 m-long undulator at the 12 GeV storage ring PETRA delivers hard X-ray photons usable up to 300 keV. The photon intensity is measured on an absolute scale in the energy range between 16 and 60 keV and compared with calculated intensities. The experimental set-up described is also used to measure the horizontal and vertical emittance of the source.

Journal Article↗
PubMed1990

Acute gastroenteritis due to double infection with enteropathogenic Escherichia coli or Salmonella and another bacterial pathogen.

Two enteric bacterial pathogens were concomitantly isolated from the feces of 18 infants less than 6 months of age admitted to the Assaf Harofeh Medical Center over a 7-year period. In all but two patients stool cultures grew enteropathogenic Escherichia coli, six of serogroup 0119. The other organisms cultured were Shigella, Salmonella, Campylobacter jejuni and Aeromonas hydrophila. The usual clinical presentation was diarrhea, dehydration and vomiting of acute onset, and low grade fever. Patients with gastroenteritis due to a single agent compared with multiple pathogens had a milder course of disease, a milder degree of dehydration and acidosis, a lesser need for i.v. fluid treatment and shorter hospitalization.

Academic Medical Centers↗