Compact soft x-ray spectrometer for plasma diagnostics at the Heidelberg Electron Beam Ion Trap.

A compact flat-field soft x-ray grazing-incidence grating spectrometer equipped with a cryogenically cooled back-illuminated charge-coupled device camera was built and implemented at the Heidelberg Electron Beam Ion Trap. The instrument spans the spectral region from 1 to 37 nm using two different gratings. In slitless operation mode, it directly images a radiation source, in this case ions confined in an electron beam ion trap, with high efficiency and reaching hereby a resolving power of lambda/Deltalambda approximately =130 at 2 nm and of lambda/Deltalambda approximately =600 at 28 nm. Capable of automatized operation, its low noise and excellent stability make it an ideal instrument not only for spectroscopic diagnostics requiring wide spectral coverage but also for precision wavelength measurements.

Image charge effects on electron capture by dust grains in dusty plasmas.

Electron-capture processes by negatively charged dust grains from hydrogenic ions in dusty plasmas are investigated in accordance with the classical Bohr-Lindhard model. The attractive interaction between the electron in a hydrogenic ion and its own image charge inside the dust grain is included to obtain the total interaction energy between the electron and the dust grain. The electron-capture radius is determined by the total interaction energy and the kinetic energy of the released electron in the frame of the projectile dust grain. The classical straight-line trajectory approximation is applied to the motion of the ion in order to visualize the electron-capture cross section as a function of the impact parameter, kinetic energy of the projectile ion, and dust charge. It is found that the image charge inside the dust grain plays a significant role in the electron-capture process near the surface of the dust grain. The electron-capture cross section is found to be quite sensitive to the collision energy and dust charge.

Expression of the Newcastle disease virus (NDV) fusion glycoprotein and vaccination against NDV challenge with a recombinant baculovirus.

The hybrid baculovirus constructed from Autographa california nuclear polyhedrosis virus (NPV) and Bombyx mori (silkworm) NPV was used for expression of fusion glycoprotein (F) of Newcastle disease virus (NDV) strain D26. The gene encoding F protein was introduced into the improved baculovirus expression vector derived from the host-range-expanded baculovirus. In Spodoptera frugiperda (fall armyworm) cells infected with a recombinant baculovirus, HyF121, the expressed F protein was properly located onto the cell surface. After silkworm pupae were infected with HyF121, a subunit vaccine against NDV was prepared from the HyF121-infected pupae. Chickens inoculated with the subunit vaccine were protected against virulent NDV challenge.

Characteristics of the neutron field in the KEK counter hall.

We have measured the neutron leakage spectra outside the shielding in the KEK counter hall using a multisphere technique supplemented by the 12C(n, 2n)11C reaction in a carbon activation detector. The neutron spectra were derived from the measurements using the LOUHI78 unfolding code. The shape of these unfolded neutron spectra matched very closely that of spectra calculated by O'Brien and McLaughlin. A comparison of the dose equivalent as derived from the spectra with that measured by a neutron dose equivalent meter confirmed that the dose equivalent meter measurements usually underestimate the dose equivalent by at least 30%.

LET distributions from CR-39 plates on Space Shuttle missions STS-84 and STS-91 and a comparison of the results of the CR-39 plates with those of RRMD-II and RRMD-III telescopes.

The LET distributions during the Space Shuttle missions STS-84 (altitude 270-412 km, average 375 km; inclination angle, 51.6 degrees) and STS-91 (altitude 328-397 km, average 373 km; inclination angle, 51.6 degrees) were measured using CR-39 plastic nuclear track detectors. A correction for the dip-angle dependence of the track-formation sensitivity of the CR-39 plates was applied to the data analysis. The absorbed doses and the dose equivalents around RRMD Detector Units, estimated from the LET distributions in the LET region of 4-200 keV/micrometers, fluctuated with standard deviations of +/- 21% to +/- 35% in both flight experiments. The LET distributions obtained from the CR-39 plates agreed well with that obtained from RRMD-II in STS-91. However, the particle fluxes obtained from RRMD-III in STS-84 and STS-91 were two or three times higher than those obtained from RRMD-II and the CR-39 plates. It was concluded that the LET distributions obtained from RRMD-II and the CR-39 plates in the present flight experiments did not include the contribution of target-fragmented secondary heavy particles produced by low-LET particles, such as relativistic or semi-relativistic protons and helium ions, whereas RRMD-III was able to detect these secondary particles because of its low triggering level.

Exploring relativistic many-body recoil effects in highly charged ions.

The relativistic recoil effect has been the object of experimental investigations using highly charged ions at the Heidelberg electron beam ion trap. Its scaling with the nuclear charge Z boosts its contribution to a measurable level in the magnetic-dipole (M1) transitions of B- and Be-like Ar ions. The isotope shifts of 36Ar versus 40Ar have been detected with sub-ppm accuracy, and the recoil effect contribution was extracted from the 1s(2)2s(2)2p 2P(1/2) - 2P(3/2) transition in Ar13+ and the 1s(2)2s2p 3P1-3P2 transition in Ar14+. The experimental isotope shifts of 0.00123(6) nm (Ar13+) and 0.00120(10) nm (Ar14+) are in agreement with our present predictions of 0.00123(5) nm (Ar13+) and 0.00122(5) nm (Ar14+) based on the total relativistic recoil operator, confirming that a thorough understanding of correlated relativistic electron dynamics is necessary even in a region of intermediate nuclear charges.

State-selective quantum interference observed in the recombination of highly charged Hg 75+...78+ mercury ions in an electron beam ion trap.

We present experimental data on the state-selective quantum interference between different pathways of photorecombination, namely, radiative and dielectronic recombination, in the KLL resonances of highly charged mercury ions. The interference, observed for well resolved electronic states in the Heidelberg electron beam ion trap, manifests itself in the asymmetry of line shapes, characterized by "Fano factors," which have been determined with unprecedented precision, as well as their excitation energies, for several strong dielectronic resonances.

Relativistic electron correlation, quantum electrodynamics, and the lifetime of the 1s(2)2s(2)2p2p0(3/2) level in boronlike argon.

The lifetime of the Ar13+ 1s(2)2s(2)2p2p0(3/2) metastable level was determined at the Heidelberg Electron Beam Ion Trap to be 9.573(4)(5). The accuracy level of one per thousand makes this measurement sensitive to quantum electrodynamic effects like the electron anomalous magnetic moment (EAMM) and to relativistic electron-electron correlation effects like the frequency-dependent Breit interaction. Theoretical predictions, adjusted for the EAMM, cluster about a lifetime that is approximately shorter than our experimental result.

Observation of the isomer effect on charge transfer from C3H4 molecules (allene and propyne) at keV energies.

The apparent isomer effect on charge transfer processes in collisions of the ground-state C+ ions with allene and propyne, which have the same C3H4 molecular chemical notation, has been observed experimentally in the collision energy from 0.2 to 4.5 keV. The difference in total charge transfer cross sections between the two isomers was found to be 32% at 0.2 keV, although it decreases to 10% at 4.5 keV. This difference is out of experimental uncertainty of 14.6% at least below the collision energy of 0.5 keV and should be regarded as a real isomer effect. Theoretical analysis based on a molecular orbital expansion method has also confirmed the experimental finding and provided the rationale.

[Morphological study of periodontal tissues in the initial stage of periodontal disease. Part 1. Application of a morphological measurement and a system for evaluating the periodontal status].

The functional aberration of occlusion, based on the morphology of the alveolar process, causes chronic irritation of the periodontium in addition to the concomitant effect of other local environment factors. This investigation was designed to study the role of morphological characteristics in the periodontal disease process. The periodontal health of 22 subjects was recorded by clinical and roentgenological measurements of the loss of periodontal tissue. The criteria for this selection were no loss of or a crowding of adjoining teeth and no disharmony in occlusal contact. Morphological data were measured around the premolars and molars of lower jaws on the study models individuals, in bucco-lingual width of the alveolar bone in relationship to the width of the crown and the sagittal figure of the Spee curve etc. by using a three-dimensional analyzer. The subjects were categorized as Type II when the records indicated a ratio of the crown width/bone width of 1/1.2. Types I and III, depended on a greater and smaller ratio, respectively. Type W symbolized the alveolar process, of which the interproximal bone showed a considerable curvature mediodistally. Type F showed a flat pattern. The sagittal figure of the Spee curve was divided into four patterns: Pattern A or B, when the cusp of the canine and first premolar leveled over or on the occlusal plane; Pattern C, when the cusp of the canine leveled over and the first premolar under the occlusal plane, and Pattern D, when all cusps, canine, premolar and molar, were under the occlusal plane. The distance from the occlusal plane to the deepest point of the Spee curve was divided into four groups: Pattern a, when the distance was 0-1.0 mm, Pattern b, 1.1-2.0 mm, Pattern c, 2.1-3.0 mm and Pattern d, 3.1-4.0 mm. These results suggest that the morphological evaluation is a useful diagnostic indicators on a rational basis. The morphological characteristics might be related to the presence of periodontal disease and allowed to speculate the pathological changes in established stage, and also to the response to periodontal treatment in the initial stage of periodontal disease.

[The clinical and etiological study on juvenile periodontal disease].

Seven juvenile periodontally diseased patients were evaluated for clinical, microbiologic and local or systemic host factors. Three patients showed the localized from of periodontitis clinically and radiographically and by deep periodontal pockets associated with the molars and incisors. Four were in the generalized froms, in which in most cases all teeth were affected. The results in both diseased froms on the predominant cultivable subgingival microflora, the composition of which was not different from that in adult periodontitis, consisted of significantly increased proportions of Gram-negative anaerobic rods, Bacteroides sp. and B. gingivalis, Haemophilus sp. and H. actinomycetemcomitans were detected in 1/3 of the localized and 2/4 of the generalized periodontitis. They were of no value in distinguishing activity that enhanced disease in the generalized from. Elevated serum IgG responses were noted with B. gingivalis. No markedly functional abnormalities of neutrophils from peripheral blood have been demonstrated, however it might function with systemic factors, like an insulin-dependent diabetes. Morphologic characteristics of the oral and periodontal tissue in localized periodontitis were that the pattern of destruction was confined to specific teeth groups characterized by extensive the bucco-lingual width ratio of the dental crown to alveolar bone width. These observations indicate that the generalized form of juvenile periodontitis lesions were associated not only with the presence of subgingival bacteria, but also with conditions such as local morphologic and systemic or constitutional factors, individual variation in relation to destructive and protective aspects of the defense mechanisms.

[Group therapy for periodontal disease. 1. Practical application of CPITN and the effects of group therapy].

The purpose of this study was to determine the oral conditions in bakery workers (473 subjects) in addition to the screening system of O'Leary and CPITN, designed for rapid recording of the level of periodontal treatment needs, and to evaluate the periodontal treatments, managed by professional cleaning (scaling) and oral hygiene instruction. The assessment of the prevalence and severity of periodontal disease and resultant treatment needs in this group showed the characteristics of chronic periodontal disease in an advanced stage in persons aged 25-29 and 50-54. 228 patients were selected for treatment for nine months and examined accurately for their periodontal condition. 137 patients continued the following group therapy three times and were reevaluated. Following the group therapy, the oral hygiene status and subjective symptoms of bleeding were improved in all groups, the effectiveness of the treatment on sextants, scoring cord three, four, showed markedly high. To achieve the treatment with few individual appointments, it is necessary to increase our knowledge of how these groups live, depending on the diversity of life style and the differences in ethnic consciousness.

[Morphological study of periodontal tissues in the initial stage of periodontal disease. Part 2. Analysis of morphological measurement and status of periodontal disease].

The morphological characteristics of periodontal tissue in periodontal disease have been interpreted differently by a number of clinical observers. Many have reported that the malposition and functional malocclusion of teeth is injurious to the periodontium. We reported in Part I that a system for evaluating periodontal status was developed for the diagnosis and management of the interproximal area at the initial stage of bone resorption. The patient group consisted of 36 adults, from 21 to 55 years of age. The severity score represented the calculated loss of periodontal support tissues: loss of alveolar bone, evaluated roentgenologically, bone level and pattern in vertical and horizontal form, periodontal pocket and gingival inflammation. Because poor oral hygiene and other factors caused swelling by gingival inflammation, we obtained study specimens from patients with chronic periodontal disease after a few tooth brushing instructions, and scalings during initial therapy in order to detect initial and established pathological changes in periodontal tissue. The purpose of this study was to clarify the relationship between periodontal disease status and morphological diagnostic indicators and different degrees of harmony and disharmony in the lower jaw. In all age groups the average percentage of bone loss and intraosseous defects tended to be higher in the groups categorized as Type III and Type F, and in the area that showed a very deep concave Spee curve to the occlusal plane in Pattern D. We considered that these morphological characteristics might be of secondary importance for diagnosis. Oral local factors were the primary extrinsic factor in the pathogenesis of horizontal and vertical interproximal bone absorption in the area of the premolars and molars.