Abstract: A formulation for forming a styrene-based scintillator using light-directed additive manufacturing techniques includes a base monomer, a primary dye, a secondary dye, and a cationic photoinitiator. The base monomer includes one or more styrene-derivative monomers.

Abstract: An ink for forming a scintillator product includes a phenylated siloxane polymer having at least one functional group per molecule for crosslinking, a filler having a refractive index about matching a refractive index of the phenylated siloxane polymer, where the refractive indices are within about 5% of one another, a rheology modifier, and at least one fluorescent dye.

Abstract: The invention relates to a system for estimating the agricultural yield of a cultivated plot comprising a plurality of crops, the system comprising: —a radar unit (1) having: —a radar (11) configured to acquire at least one image of the cultivated plot, said radar operating in the field of frequency-modulated continuous waves; —a focusing unit (12) configured to focus a radar beam in an acquisition direction; a processing unit (2) configured to carry out steps of: acquiring (E1), for each position of the radar; processing (E2) the acquired image to extract therefrom at least one data item representative of the yield of the cultivated plot; determining (E3) the yield of the cultivated crop on the basis of the extracted data.

Abstract: A traveling wave tube designed to operate as an amplifier within plural frequency bands, which includes a microwave line through which electrons travel and in which a signal is amplified. The microwave line includes, in succession, an input section separated from a succession of gapped output sections, each output section working within one of the operating frequency bands of the traveling wave tube. The input section, connected at one end to an input for injecting the signal to be amplified, works within a frequency band encompassing the operating frequency bands of the traveling wave tube and is intended to preamplify the signal to be amplified. The succession of output sections receives the preamplified signal, each of the output sections being intended to amplify it if the signal is at a frequency lying within its working frequency band and to let it pass through virtually without any interaction if it is at a frequency outside its working frequency band.

Abstract: Disclosed is a method for the construction of helix travelling wave tubes in which the helix is supported by insulating dielectric supports, wherein the dielectric supports, in turn, are supported by support-forming elements which project from the internal wall of the vacuum-tight casing surrounding the set, towards the helix, thus reducing the radial dimensions of the dielectric supports. In most of the embodiments, these novel support-forming elements are made of metallic material. The disclosed method greatly simplifies the construction of delay lines with low dispersion for travelling wave tubes with very great bandwidth while, at the same time, increasing the precision of assembly that can be obtained. An additional advantage of the reduction of the radial dimensions of the dielectric lies in an improvement of the possibilities of thermal conduction from the helix to the casing that surrounds the set.

Abstract: Disclosed is a travelling-wave tube with helix. The helix is mounted in a metal sleeve and is held in a centered position by at least three dielectric rods. Parts of the helix are in contact with the rods. The helix is made out of a thin strip of a metal that is a good conductor of heat and electricity. Instead of having a rectangular cross-section, the thin strip now has a T-shaped cross-section, at least at all the parts of the helix that are in contact with the rods. The base of the T is brazed to the rods. This structure prevents the risk of electric arcs at the facing brazing beads on two consecutive turns of the helix. The disclosure can be applied to travelling-wave tubes operating in wide bandwidth and at high peak power and/or mean power values.

Abstract: This invention pertains to a travelling wave tube with a helix-type delay line attached to a sleeve through the use of boron nitride dielectric supports, which have a layer of insulating material with a secondary emission coefficient greater than 1, such as aluminum or beryllium oxide, for example.

Abstract: A travelling-wave tube has a cylindrical sleeve containing a delay line and a coupling device between the delay line and an external microwave circuit for removal or injection of microwave energy. This external circuit comprises a transmission line possessing a conductive internal core. A conductive part is placed at one end of the delay line. It has a coupling pin that projects inwards into the sleeve and is brazed to an end of the delay line. The conductive part is brazed to the sleeve. The coupling between the delay line and the external circuit is made between the part and the internal conductive core of the transmission line. This coupling is without contact, a narrow gap being prepared between the external surface of the part located on the side of the coupling pin and the internal conductive core.

Abstract: The invention provides a travelling wave tube comprising means for suppressing parasite oscillations and these means are formed by auxiliary helical delay lines placed inside the sleeve in the gaps between two adjacent dielectric supports, periodically fixed to the sleeve by metal supports and without contact with the main helical delay line.