Radiation chemical processes in poly(methacrylate) and chlorinated polyphenylmethacrylate after ion- and electron-beam irradiation are analyzed by means of TL- and ESCA-measurements. The results are in accordance with proposed models for degradation and crosslinking mechanisms of the polymers. A correlation is found between the TL intensity and the sensitivity of positive resists based on poly(methacrylates).

The detailed spectroscopic study of transient free CF radicals with the resonance enhanced multiphoton ionization (REMPI) method is the aim of this paper. The CF radicals were generated from the gaseous (50—200 Pa) halocarbons CCl3F, CCl2F2, CClF3, 1,2-C2Cl2F4, C2ClF3, and C6F6by a combined infrared and UV/VIS laser photolysis. Because of the small absorption of the halocarbon molecules in the dye laser range used (328—485 nm) a preceding production of precursors (capable of absorbing dye laser photons) was necessary, which was achieved by IR multiphoton dissociation of the parent molecules with a TEA CO2laser pulse. In a subsequent absorption of UV/VIS dye laser photons the precursors were photolyzed yielding CF radicals. These could be spectroscopically investigated by their REMPI signals in a (2 + 1)-photon absorption process in the focussed radiation of the same dye laser pulse. About 20 vibrational bands were measured, rotationally resolved, and were assigned to a two-photon 3pπD2Πr←←X2Πrresonant transition followed by one-photon absorption for direct ionization of CF. Compared to the cold CF radicals, commonly extracted from a flow reactor, the laser-photolytically generated CF radicals were found to be vibrationally and rotationally extremely excited (v″ ≤ 12,J≤ 80.5). Using the wide rotational contour of the vibrational bands we could determine with greater precision than before the electronic, vibrational, and rotational constantsTe, ωe, ωexe, ωeye,Av,Bv, andDv, respectively, for the Rydberg state 3pπD2Πr(v′ = 0—6) and the electronic ground stateX2Πr(v″ = 0—12). Based on these constants we calculated the Morse and the Dunham potential curves for both states. A detailed study of missing and shifted rovibronic lines of theDstate yielded first information on the vibrational levelsv′ = 3, 4, and 5 of theB2Δrvalence state, which cannot be measured directly by REMPI. Additionally, we measured for the first time in the UV wavelength range a (1 + 1)-photon REMPI spectrum belonging to the vibrational bandsv′ = 0 ←v″ = 0 andv′ = 1 ←v″ = 0 of theA2Σ+←X2Πrtransition. Even in the range of high rotational quantum numbersJwe found no indication of Λ-type doubling of the rovibronic states within a resolution of 0.2 cm−1.

The unimolecular decomposition of the halogenated methanes CF2HCl (one main channel) and CF2Cl2 (two main channels) in the focused beam of a pulsed CO2 laser under high pressure and fluence conditions (p=100 Pa–2 kPa; Φ=5–200 J/cm2) was studied by a special laser-induced fluorescence (LIF) technique, permitting spatially resolved fragment concentration measurements in the focal region. Considerable amounts of CF2 product were formed after the end of the laser pulse. In the one-channel-dissociation case of CF2HCl LIF measurements of the CF2 yield distribution Y(z,r) can be related to the spatial distribution of the average absorbed energy in the parent molecules. Only part of the absorbed energy is consumed by multiphoton dissociation, while most reactant molecules remain highly vibrationally excited in the focus volume far into the double cone. Using the long-lived CF2 also as a probe for measuring the rotational, translational, and vibrational temperatures, the redistribution of the internal energy in the molecules and fragments involved is monitored. The post-pulse production of CF2 is shown to be caused by the energy pooling v–v transfer mechanism, while contributions of pyrolytic and gas dynamic processes are of little importance.

In this paper, we investigate the rotationally resolved spectra of hot CF radicals generated after IR multiphoton dissociation (IRMPD) of CFCl3 or CF2Cl2 and subsequent UV photodissociation. It is shown that these conditions are advantageous for the spectroscopy of transitions involving high rotational quantum numbers and hot bands. Thus molecular constants of CF for the first vibrationally excited state of the electronic ground state (Av=77.1 cm−1, Bv=1.389 cm−1, Dv=6.570×10−6 cm−1) are determined for the first time or are calculated more accurately. The spectroscopic method used was resonance-enhanced multiphoton ionization (REMPI) spectroscopy.

A laser-induced fluorescence (LIF) method for spatially resolved fragment detection and characterization in the radiation field of a photolysis laser is described. Measurements of the radiation field of a focused beam showed up highly inhomogeneous irradiation conditions, resulting in a strong local dependence of the laser-induced processes. The spatial resolution of the method is based on stepping-motor-controlled motion of the focusing lens of the photolysis laser versus the probe laser focused to a diameter (1/e2) of 58 μm. This diameter corresponds to the spatial inhomogeneities of the quantities studied in this article. However, the monitored volume (5.3×10−6 cm3) also represents a compromise between acceptable S/N ratio and spectral resolution. The advantages and limits of this spatially resolved fluorescence (SRF) technique are discussed. Owing to its simplicity it can be readily implemented in existing laser photolysis equipment with conventional LIF detection. This method is currently being applied to the study of IR laser chemical reactions. A few examples illustrate the range of applicability of the method by providing information on the fluence dependence of product formation, on mass transport kinetics of molecular species in the context of heterogeneous laser processing, and on the internal energy distribution of the dissociation products. They show the much higher information content of SRF measurements as compared with conventional LIF measurements.

The principle of a setup for realtime mass-spectrometry of gas phase reactions is described. An orifice between the high pressure (about 200 Pa) reaction cell and the quadrupol mass spectrometer reduces the pressure and controls some important performance parameter. . With this method it is also possible to investigate the kinetics of laser-induced gas/surface reactions. Some results for C02laser-induced reactions in the system SF6/Si are presented. 1.

Excitation spectra and dispersed fluorescence were measured in the β-system (B2Σ-X2π) of the SiF radical produced by multiphoton dissociation (MPD) of SiF4 with a TEA CO2 laser. Within the limits of error no effect of the wavelength of the photolysis laser on the spectra was found. Formation and decay kinetics of SiF during and after IR laser excitation, as monitored by LIF, are also presented. The teporal behaviour of the SiF LIF signal was different for different wavelengths of the CO2 laser. For wavelengths close to the linear absorption band there was no induction period in the formation of SiF. The pressure dependence of the kinetics was different for the two CO2 laser branches.

Im Rahmen einer prospektiven Einjahresdokumentation wurden 54 polytraumatisierte Patienten untersucht. Dokumentiert und ausgewertet wurden: Unfallhergang, Zustand bei stationärer Aufnahme, Verlauf unter besonderer Berücksichtigung der zellvermittelten Immunität mit Multitest Merieux, nachstationärer Verlauf.

Radiation chemical processes in polyphenylmethacrylate and several chlorinated polyphenylmethacrylate samples are analyzed by means of radiothermoluminescence. The spectral distribution of the luminescence was also studied in dependence on the temperature. The observed results show that the chlorine atoms play a dominating role in the radiation chemical reactions.

Acta PolymericaVolume 36, Issue 1 p. 65-66 Kurzemitteilungen UV-angeregte RTL-Untersuchungen an elektronenvorbestrahlten LDPE-Proben M. Wäsche, M. Wäsche Akademie der Wissenschaften der DDR, Zentralinstitut für Physikalische Chemie, Rudower Chaussee 5, DDR-1199 BerlinSearch for more papers by this authorR. Kunze, R. Kunze Akademie der Wissenschaften der DDR, Zentralinstitut für Physikalische Chemie, Rudower Chaussee 5, DDR-1199 BerlinSearch for more papers by this authorE. Linke, E. Linke Akademie der Wissenschaften der DDR, Zentralinstitut für Physikalische Chemie, Rudower Chaussee 5, DDR-1199 BerlinSearch for more papers by this author M. Wäsche, M. Wäsche Akademie der Wissenschaften der DDR, Zentralinstitut für Physikalische Chemie, Rudower Chaussee 5, DDR-1199 BerlinSearch for more papers by this authorR. Kunze, R. Kunze Akademie der Wissenschaften der DDR, Zentralinstitut für Physikalische Chemie, Rudower Chaussee 5, DDR-1199 BerlinSearch for more papers by this authorE. Linke, E. Linke Akademie der Wissenschaften der DDR, Zentralinstitut für Physikalische Chemie, Rudower Chaussee 5, DDR-1199 BerlinSearch for more papers by this author First published: January 1985 https://doi.org/10.1002/actp.1985.010360117Citations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume36, Issue1January 1985Pages 65-66 RelatedInformation

Crystal Research and TechnologyVolume 19, Issue 11 p. 1424-1424 Book Review Tribochemistry Akademie-Verlag, Berlin 1984 495 S., 329 Abb., 106 Tab. Preis: 98, – M G. Heinicke, G. HeinickeSearch for more papers by this authorH.-P. Hennig, H.-P. HennigSearch for more papers by this authorE. Linke, E. LinkeSearch for more papers by this authorU. Steinike, U. SteinikeSearch for more papers by this authorK.-P. Thiessen, K.-P. ThiessenSearch for more papers by this authorK. Meyer, K. MeyerSearch for more papers by this author G. Heinicke, G. HeinickeSearch for more papers by this authorH.-P. Hennig, H.-P. HennigSearch for more papers by this authorE. Linke, E. LinkeSearch for more papers by this authorU. Steinike, U. SteinikeSearch for more papers by this authorK.-P. Thiessen, K.-P. ThiessenSearch for more papers by this authorK. Meyer, K. MeyerSearch for more papers by this author First published: 1984 https://doi.org/10.1002/crat.2170191103Citations: 16AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume19, Issue111984Pages 1424-1424 RelatedInformation

Crack propagation in dielectric solids is connected with many structural and electronic excitation processes. In order to obtain some information on the elementary excitation mechanism, crack velocity and fracture-induced luminescence in LiF and NaF (as received; doped; X-irradiated) under high vacuum conditions were correlated. Time-resolved crack velocity measurements revealed the usually discontinuous manner of crack propagation; maximum crack velccities of 3800 m/s (LiF) and 3000 m/s (NaF) were observed. Luminescence excitation in the X-irradiated samples occured at slow crack motion i.e. for increased plastic processes in the crack tip zone. The luminescence was explained by the recombination of stabilized radiation defects (F-centres and interstitial halogen atoms) involving a radiative exciton decay. The recombination is triggered by the crack via mobilization of the recombination partners by dislocations or lattice deformation processes.

Using the apparatus for investigations of mechanically induced excited states, which is described in Part I of this paper, the electron emission from mechanically treated alkali halide crystals and their surface charge distribution is measured. While the spontaneous postemission (not depending on temperature below RT) of electrons after mechanical treatment can be explained as field emission from surface traps, the TSEE low-temperature glow peaks are ascribed to the decay of defect electron centres. A simple mechanism is suggested to understand the mechanically induced excitation process. Measurements of the locally resolved OSEE show the necessity to know the charge structure in order to interprete the emission relief properly. Unter Benutzung der in Teil I dieser Arbeit beschriebenen Apparatur zur Untersuchung mechanisch induzierter Anregungszustände wurden Messungen der Elektronenemission von mechanisch beanspruchten Alkalihalogenidkristallen sowie deren Ladungsstruktur durchgeführt. Während die (unterhalb RT temperaturunabhängige) spontane Nachemission von Elektronen nach mechanischer Bearbeitung als Feldemission aus Oberflächenstörstellen gedeutet wird, sind die Tieftemperatur-Glowpeaks der TSEE auf den Zerfall von Defektelektronenzentren zurückzuführen. Vorstellungen zum mechanisch induzierten Anregungsprozeß werden dargestellt. Messungen der örtlich aufgelösten OSEE bestätigen die Notwendigkeit der Kenntnis der Ladungsstruktur bei der Interpretation des Emissionsreliefs.

In part I of this paper a complex apparatus is described which enables the investigation of mechanically induced excited states on cleavage planes of alkali halide crystals. The charge distribution of a 6 × 6 mm2 cleavage plane can be measured without contact and with a local resolution better than 100 μm. The charge density can be determined quantitatively. In the same apparatus the thermally stimulated electron emission (TSEE) of the crystal, and, using a light probe, the locally resolved optically stimulated electron emission (OSEE) can be investigated. In part II of this paper results of the measurements are given. Im ersten Teil dieser Arbeit wird eine komplexe Apparatur zur Untersuchung mechanisch induzierter Anregungszustände auf Spaltflächen von Alkalihalogenidkristallen beschrieben. Auf etwa 6 × 6 mm2 großen Spaltflächen kann die elektrostatische Ladungsverteilung kontaktlos mit einer örtlichen Auflösung von etwa 100 μm gemessen werden. Die Ladungsdichte kann quantitativ bestimmt werden. In der gleichen Apparatur können die thermisch stimulierte Elektronenemission (TSEE) der Kristalle und – bei Verwendung einer Lichtsonde – die örtlich aufgelöste optisch stimulierte Elektronenemission (OSEE) untersucht werden. Im zweiten Teil der Arbeit wird über Meßergebnisse berichtet.