Author: Carl Clifford GarberPublisher:
ISBN:
Category : Helium
Languages : en
Pages : 494
Book Description
A Study of the Generation of Vacuum Ultraviolet Radiation from Discharges in Helium
Author: Carl Clifford GarberPublisher:
ISBN:
Category : Helium
Languages : en
Pages : 494
Book Description
A Helium Radiation Source for Vacuum Ultraviolet Use
Author: Irving Herbert ThomaePublisher:
ISBN:
Category :
Languages : en
Pages : 84
Book Description
Research Studies on Techniques for Generation of Ultraviolet and Vacuum Ultraviolet Radiation
Author: Stanford University. Microwave LaboratoryPublisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Generation of Coherent and Incoherent Vacuum Ultraviolet Radiation
Author: Ludwik Jerzy ZychPublisher:
ISBN:
Category : Ultraviolet radiation
Languages : en
Pages : 164
Book Description
Helium Continuum Afterglow in the Vacuum Ultraviolet
Author: Robert E. HuffmanPublisher:
ISBN:
Category : Afterglow (Physics)
Languages : en
Pages : 12
Book Description
New Vacuum Ultraviolet Emission Continua in the Rare Gases
Author: Robert E. HuffmanPublisher:
ISBN:
Category : Emission spectroscopy
Languages : en
Pages : 38
Book Description
Several new vacuum ultraviolet-emission continua recently observed in the spectra of the rare gases helium, argon, and xenon are discussed. These spectra were produced with a windowless light source operated as a repetitive condensed discharge and equipped with a differential pumping system to separate the high pressure (up to 800 mm Hg of helium) light source from the 2-m vacuum spectrograph (pressure 1/1000 mm Hg). In helium two continua were observed at pressures above 150 mm in addition to the weaker 600 to 950 angstroms continuum. The brightest extends from about 1050 to above 4000 angstroms and seems connected with greatly enhanced lines of He(II). The other continuum is the completely broadened principal series extending from 584 to about 510 angstroms and containing broadened principal series absorption lines. With argon in a flow system or xenon isolated with a LiF window, previously observed continua were extended from their resonance lines to beyond 3000 angstroms. Details of the experimental observations and possible explanations of these continua are presented. (Author).
New Excitation Unit for the Rare Gas Continua in the Vacuum Ultraviolet
Author: Robert E. HuffmanPublisher:
ISBN:
Category : Far ultraviolet radiation
Languages : en
Pages : 16
Book Description
On the Spectra of Helium, Hydrogen and Carbon in the Extreme Ultraviolet
Author: John Cunningham McLennanPublisher:
ISBN:
Category : Carbon
Languages : en
Pages : 28
Book Description
Air Force Research Resumés
Author: Ultraviolet Light Generation from a Helium Plasma as a Function of Radio Frequency Power and Gas Pressure
Author: Ahmed AlanaziPublisher:
ISBN: 9781392024010
Category : Helium
Languages : en
Pages : 100
Book Description
Ultraviolet (UV) light emission is generated by exciting ground state helium to excited states, where the characteristic UV emission lines are referred to as the helium I and helium II emission lines. Excited He is achieved by pumping He gas with electromagnetic (EM) energy, where both ionized and excited He co-exist, known as a He gas plasma. The intensity UV emission by the He plasma increases with EM pumping power and the He gas pressure. Consequently, He plasmas are used as UV light sources. The highest intensity He UV light sources incorporate electron cyclotron resonance (ECR), where ECR increases the light intensity by increasing the probability of collision between the free electrons in the plasma with the He atoms. This class of high intensity UV light sources exclusively us microwaves to generate the He plasma. To the best of our knowledge, no one has attempted to use radio frequency (RF) EM radiation in high intensity UV light sources. Why not? RF plasmas are much easier to generate and control. All that is required is a simple electronic matching network for tuning the plasma, while a microwave plasma requires an antenna and a resonance chamber for tuning. In the present study, a high intensity He UV light source has been constructed using a ECR enhanced RF He plasma. Due to the absorption of low energy UV light by air, the emission and energy of the UV source has been indirectly measured by monitoring the photoelectron current of a gold target placed in the beam of the light source and rationalized by comparing to spectroscopy data reported for He plasmas. At low gas pressure the profile of the photocurrent consists of two pair of maxima. The pair of maxima in the low He gas pressure regime are assigned to the helium II emission lines with photon energies of 40.8 eV and 48.3 eV, respectively. In the high He pressure regime the pair of maxima are assigned to helium I emission lines at photon energies of 21.2 eV and 23.1 eV, respectively. Photocurrents of the order of a few pA have been obtained, as opposed to tens of nA for a traditional DC He UV light source.