Strong temperature effect on X-ray photo-etching of polytetrafluoroethylene using a 10 Hz laser-plasma radiation source based on a gas puff target

The first results of experiments on direct photo-etching of heated PTFE using a 10 Hz X-ray source based on a laser-irradiated gas puff target are presented. X-ray radiation in the wavelength range from 6 to 20 nm was produced as a result of irradiation of a double-stream gas puff target with Nd:YAG laser pulses of energy 0.8 J and time duration 3 ns. The resulting X-ray pulses with energy of about 100–200 mJ were used to irradiate samples of PTFE to create microstructures by direct photo-etching. Strong enhancement of the photo-etching process was observed for samples heated up to 300 °C. PACS 52.38.Ph; 81.65.Cf; 61.82.Pv     

Synthese de fluoro-3 azacyclanes : action de l'acide fluorhydriqiue sur les aza-1 bicyclo [n.1.0] alcanes

The addition of liquid hydrogen fluoride or Olah's reagent (pyridin-10 HF) to 1-aza bicyclo [n.1.0] alkanes leads to the formation of 3-fluoro 1-aza heterocyclic compounds. Isomeric 3-fluoro azetidines, 3-fluoro piperidines and a 3-fluoro azepine have been prepared by this procedure.     

A New Route to 3-Phosphonylpyrazoles

The regioselective synthesis of 3-diethoxyphosphonopyrazoles has been accomplished through the addition of aryl or alkyl hydrazines to (3-ethoxyacryloyl)phosphonic acid diethyl ester. An example of hydrolysis of the pyrazolephosphonic ester to the corresponding acid is described.     

Laser-produced plasma EUV source based on tin-rich, thin-layer?targets

In this paper a new approach to a laser-produced plasma EUV source based on a tin target is presented. A?thin layer of pure tin and composite layers consisting of Sn with Si, SiO and LiF are investigated. The target composed of several thin layers produces less debris than the other targets and provides a conversion efficiency (CE) in the 13.5-nm±1% band at least comparable to the CE for the pure tin slab target. The largest CE was observed for the target composed of a mixture of Sn and LiF, due to the fact that lithium, similarly to tin, is a strong emitter at 13.5?nm.     

Optical and X-ray emission spectroscopy of high-power laser-induced dielectric breakdown in molecular gases and their mixtures

Large-scale plasma was created in molecular gases (CO, CO2, N2, H2O) and their mixtures by high-power laser-induced dielectric breakdown (LIDB). Compositions of the mixtures used are those suggested for the early earth's atmosphere of neutral and/or mildly reducing character. Time-integrated optical spectra emitted from the laser spark have been measured and analyzed. The spectra of the plasma generated in the CO-containing mixtures are dominated by emission of both C2 and CN radicals. A vibrational temperature of approximately 10(4) K was determined according to an intensity distribution in a vibronic structure of the CN (B2Sigma(+)u-X2Sigma(+)g) violet band. For comparison, the NH3-CH4-H2-H2O mixture has been irradiated as a model of the strongly reducing version of the early earth's atmosphere. In this mixture, excited CN seems to be significantly less abundant than C2. The LIDB experiments were in the molecular gases carried out not only in the static cell but also using a large, double stream pulse jet (gas puff target) placed in the vacuum interaction chamber. The obtained soft X-ray emission spectra indicate the presence of highly charged atomic ions in the hot core of high-power laser sparks.     

Molecular structure and some reactivity aspects of 2,6-diamino-4(3H)-pyrimidinone monohydrate

Crystals of C₄H₆N₄O·H₂O are orthorhombic:Pbca,a=16.721(2),b=4.242(1),c=18.293(2)Å,Z=8. The structure has been solved by direct methods and refined by full-matrix least-squares techniques toR=0.046 for 1252 unique reflections. The structure consists of approximately planar molecules of the 3(H)4-one tautomer. Delocalization of the ring and the C=O-electrons, and conjugation of the lone-pair electrons of the amine groups with the pyrimidinone nucleus are observed. The molecules are connected by O-HO, N-HN, and N-HO hydrogen bonds. The molecular structure clarifies the chemical properties of the compound.     

Synthesis and crystal structure of 1-acetyl-3-bromo-3-phenylazetidine and 1-phenyl-2-(N-acetyl-N-formyl)-aminoethanone

1-Acetyl-3-bromo-3-phenylazetidine (1), C₁₁H₁₂BrNO, has been synthesized and characterized by spectroscopic methods and single crystal X-ray analysis. It crystallizes in the space group P2 ₁/c with a = 8.633(1), b = 7.461(1), c = 17.204(1) Å, = 98.403(7)°, V = 1096.2(2) ų, Z = 4, D _calc = 1.540 g cm^–3. The azetidine ring is nearly planar since the four atoms are within ±0.039(5) Å of the mean square plane calculated for the heterocycle. The attempt to obtain a highly strained 2-azetine derivative from the above compound gave, surprisingly, 1-phenyl-2-(N-acetyl-N-formyl)-aminoethanone (2), C₁₁H₁₁NO₃. This compound has been also characterized by spectroscopic methods and single crystal X-ray analysis. It crystallizes in the space group P2₁2₁2₁, with a = 5.4719(3), b = 8.3205(6), c = 23.298(3) Å, V = 1060.7(2) ų, Z = 4, D _calc = 1.286 g cm^–3. The aminoethanone residue is in a near planar conformation where the torsion angles are 7(2)° for N–C–C–=O and –173(2)° for N–C–C–C(Ph).     

Extreme ultraviolet tomography of multi-jet gas puff target for high-order harmonic generation

A volume, tomographic reconstruction of a novel, multi-jet gas puff target, developed for possible applications in high-order harmonic generation (HHG), is presented. The target, produced by pulsed injection of argon gas through nozzle in a form of linearly oriented small orifices, has been characterized in the extreme ultraviolet at 13.5 nm wavelength. Target density estimations were performed, and 3-D representation of pulsed gaseous target has been obtained by combining 2-D shadowgram images, recorded at various rotation angles. More detailed information about higher-order jets, formed as a result of collisions of primary jets, was obtained. Tomographic studies of such type of targets dedicated for HHG have been obtained to our knowledge for the first time.