51 results about "Cherenkov radiation" patented technology

A waveguide, such as a holey fiber or other optical fiber, is tapered to control the dispersion in a manner which varies along the length of the tapered portion of the fiber, thus providing the desired characteristics of the fiber. The longitudinal variation of the phase-matching conditions for Cherenkov radiation (CR) and four-wave mixing (FWM) introduced by DMM allow the generation of low-noise supercontinuum. The flexibility of the design permits the designer to control the tapering to select the bandwidth, the center frequency, or both. The holey fiber can be a polarization-maintaining fiber.

An apparatus and methods for generating a substantially supercontinuum-free widely-tunable multimilliwatt source of radiation characterized by a narrowband line profile. The apparatus and methods employ nonlinear optical mechanisms in a nonlinear photonic crystal fiber (PCF) by detuning the wavelength of a pump laser to a significant extent relative to the zero-dispersion wavelength (ZDW) of the PCF. Optical phenomena employed for the selective up-conversion in the PCF include, but are not limited to, four-wave mixing and Cherenkov radiation. Tunability is achieved by varying pump wavelength and power and by substituting different types of PCFs characterized by specified dispersion properties.

The invention discloses a real-time monitoring device for the neutron flux in a fission reaction. The device is characterized in that a fast neutron conversion body (1), a fluorescent light reflection tube (3), a boron plastic flash body (2), a Cherenkov light reflection tube (5) and a Cherenkov radiation body (4) are arranged in the incident direction of particles in sequence; neutrons and gamma rays enter the boron plastic flash body (2) to interact with substances to generate e+/e-, recoil protons and alpha particles, the e+/e-, the recoil protons and the alpha particles are excited to generate fluorescent light, and the fluorescent light enters a first photoelectric multiplier tube (7) through reflection of the fluorescent light reflection tube (3) and is amplified through an amplifier (10) to obtain neutron and gamma information; after secondary particles enter the Cherenkov radiation body, only e+/e- generates Cherenkov light, and the Cherenkov light is amplified through a second photoelectric multiplier tube to obtain gamma information; two signals are subjected to subtraction to obtain neutron flux information. According to the device, the n and gamma signals are judged in combination with the pulse rise time difference, so that the measurement precision of the pulsed neutron flux is further improved.

A light receiver for detecting incident time is installed on the side of a radiation source of a scintillator (including a Cherenkov radiation emitter), and information (energy, incident time, an incident position, etc.) on radiation made incident into the scintillator is obtained by the output of the light receiver. It is, thereby, possible to identify an incident position and others of radiation into the scintillator at high accuracy.

A surface polaritons Cherenkov radiation source (SPCRS) belongs to an electromagnetic wave radiation source technology field. The radiation source comprises: an electron gun, a medium torus (or a medium cylinder) and a metal film layer deposited on an internal surface of the medium torus (or deposited on an external surface of the medium cylinder). An electron beam emitted from the electron gun is swept past from a metal film layer surface so as to excite a surface polaritons wave on the metal film layer surface. The surface polaritons wave penetrates the metal film layer and arrives at a medium material layer. When a ratio beta of a moving speed of the electron beam emitted by the electron gun to a light velocity in vacuum and a refractive index n of the medium material layer satisfy a Cerenkov radiation condition which is n beta>1, the surface polaritons wave is converted into the Cerenkov radiation in the medium material layer. A radiation frequency is determined by the frequency of the surface polaritons wave excited by the electron beam. Through changing moved electron energy, the frequency of the excited surface polaritons wave can be changed so as to tune the frequency of the electromagnetic radiation source. The radiation source of the invention has a small size, a narrow bandwidth and a low voltage, and is tunable and easy to be integrated.

Some embodiments are directed to a radiation dosage monitoring system including a model generation module configured to generate a 3D surface model of a portion of a patient undergoing radiation treatment, an image detector configured to detect Cherenkov radiation and any subsequent secondary and scattered radiation originating due to the initial Cherenkov radiation emitted from the patient, a processing module configured to determine estimations of radiation applied to the patient utilizing the images from the image detector and the 3D model, and to utilize the determined estimations of radiation applied to the patient together with data indicative of the orientation of a radiation beam inducing emission of the Cherenkov radiation at a time when the radiation beam was applied to generate a 3D internal representation of the location of the portions of a irradiated patient resulting in the emission of the Cherenkov radiation.

A method of characterizing a tissue sample is provided that includes injecting a tissue sample with radiotracers, where the radiotracers include beta-emitter radio tracers, the beta-emitter radio tracers emit beta particles according to a decay of the beta-emitter radio tracers, and measuring the beta particles or Cherenkov radiation from the beta particles in the tissue sample, and determining a condition of the radio tracers in the tissue sample according to the measured beta particles or the measured Cherenkov radiation, where the determined condition includes a depth and/or a concentration of the radiotracers in the tissue sample.

Embodiments of the present invention generally relate to laser combiners, and more specifically, to all-fiber devices that combine optical laser power from multiple separate sources such as lasers or amplifiers. In one embodiment, a method of manufacturing a combiner device comprises: positioning an plurality of fibers into a bundle of fibers; drawing the bundle of fibers to create a tapered section, the tapered section having a first outer diameter at an input end, a second outer diameter at an output end, and a taper ratio of at least three; wherein at least one of the fibers of the bundle of fibers comprises an optical waveguide configured for propagating an optical mode from the input end to the output end, and wherein a mode field diameter of the optical mode at the input end is substantially the same as the mode field diameter at the output end.

The invention discloses a Cherenkov radiation device design based on an artificial surface plasmon. The Cherenkov radiation device comprises a dielectric layer and two layers of metal sheets, wherein the two layers of metal sheets are fixedly connected with two sides of the dielectric layer and are in mirror symmetry along an extension direction of the metal sheets, the radiation device is of a structure based on dual layers of artificial surface plasmon waveguides, a periodic phase reverse structure is introduced into the waveguides, and thus, structural mutation with discontinuous impedance is generated in the structure. On the basis of the artificial surface plasmon waveguides, mode conversion and high-efficiency radiation of artificial surface plasmon are achieved, and moreover, the radiation and the beam direction of the artificial surface plasmon are effectively controlled by changing dispersion characteristics; by the Cherenkov radiation device, high-efficiency conversion between a conduction mode and a space radiation mode can be achieved, the development of a device and a functional device of a novel waveguide structure can be promoted to a great extent, and the Cherenkov radiation device has important application prospect in aspects of circuits, signal transmission, processing and the like in future.

The invention discloses a device and method for measuring the divergence angle distribution of an electron beam, and the device comprises a sealed vacuum target room, a conversion target, and an anti-scattering shading column. The sealed vacuum target room is provided with a light output window corresponding to the anti-scattering shading column. The device also comprises an imaging system. After the electron beam bombards the conversion target, Cherenkov radiation light is generated, and the Cherenkov radiation light enters the anti-scattering shading column and then is outputted through the light output window. The Cherenkov radiation light is imaged on the imaging system after being filtered by a narrow band filter. According to the invention, after the electron beam bombards the conversion target, Cherenkov radiation light is generated, and the Cherenkov radiation light enters the anti-scattering shading column and then is outputted through the light output window. The focal plane imaging of the Cherenkov radiation light is carried out on the imaging system after being filtered by the narrow band filter. Through the focal plane imaging, the device deduces the divergence angle distribution of the electron beam by inversion.

The invention provides a natural hyperbolic material-based Cherenkov infrared radiation source and free electron light source, which comprises a natural hyperbolic material layer and an on-chip free electron emission source, and the on-chip free electron emission source comprises an on-chip electron source cathode and an on-chip electron source anode. In this way, the on-chip free electron emission source generates a stable electron beam to excite infrared Cherenkov radiation in the natural hyperbolic material. As the natural hyperbolic material is low in cost, easy to obtain and simple in preparation process, the natural hyperbolic material has remarkable advantages compared with an artificial hyperbolic metamaterial. Meanwhile, the natural hyperbolic material is easy to grow, good in stability and few in defect, and the influence of the material processing technology precision on the device performance can be avoided. And on the basis of a natural dielectric material, the intrinsic loss is lower, so that the corresponding device is higher in radiation power, higher in efficiency and smaller in heat emission. In addition, based on a natural crystal material, layout and arraying are easy to realize, and a possible scheme is provided for a high-power array integrated free electron light source.

The invention belongs to the crossing field of metamaterial and microwave source technology, and particularly relates to a Cherenkov-radiation-mechanism-based metamaterial slow wave structure unit and a metamaterial slow wave structure; the metamaterial slow wave structure unit comprise a hollow metal circular waveguide, a first metamaterial resonance unit and a second metamaterial resonance unit. The metamaterial slow wave structure unit has the following technical effects: the metamaterial slow wave structure unit can work under the cut-off frequency of the hollow circular waveguide with the same size, and has the advantage of miniaturization; high coupling impedance is achieved, and the effect beam wave interaction can be improved; the metamaterial slow wave structure unit has the advantage of uniform quasi TM01 mode field distribution, and the beam wave interaction efficiency can be improved through uniform field distribution; the electron beam can feel more conductor structures in the advancing process, the potential energy of the electron beam is reduced, and therefore the electron beam has larger kinetic energy, and the space limiting current is improved. The problem of structure edge field concentration caused by too thin thickness can be effectively solved, and the breakdown risk of the device is reduced; and meanwhile, a conductor part sensed by the electron beam is also added, so that the space limiting current can be improved.

The invention provides a radiotherapy position and dosage real-time monitoring and positioning device based on a CLI and structured light technology, and a tumor radiotherapy system in order to solvethe technical problems that the position of a Cherenkov radiation signal acquired by an existing tumor radiotherapy real-time monitoring synchronous acquisition device is possibly inconsistent with the position of a radiation target area, and the specific deviation position and causes cannot be positioned when a clinical deviation occurs. Three-dimensional body surface dose distribution of a patient is obtained in real time through three CLI cameras, three-dimensional body surface contour distribution of the patient is obtained in real time through three sets of position synchronous monitoringmodules, registration fusion of the three-dimensional body surface dose and the body surface contour is achieved through space coordinate transformation, and the accuracy of the radiotherapy dose andthe treatment position of the patient is monitored in real time. Once the position dose exceeds the clinical deviation, the accurate position of the dose deviation can be positioned, the deviation reason can be judged, and a basis is provided for adjusting the body position of the patient or the dose of an accelerator.

The invention provides a method and a system for measuring the beam density distribution of a high-current pulse electron beam, and solves the problem that the beam density of a complete section of the high-current pulse electron beam cannot be measured by an existing beam measurement method. The method comprises the following steps of: 1, manufacturing a Cherenkov radiation conversion target; 2, establishing a measurement system; 3, collecting a light spot image; 4, obtaining the relative intensity distribution of Cherenkov radiation through the gray value distribution of the light spot image; and 5, acquiring beam density distribution. According to the method, the design process of the Cherenkov radiation rotating target is given, so that a basis is provided for realizing beam density distribution measurement. Meanwhile, the method provides a beam spot image processing method, gray value distribution of the beam spot image is converted into beam density distribution through the method, and therefore beam density distribution measurement on the complete section of the high-current pulse electron beam is achieved.

The invention discloses a bispecific nano-micelle based on folic acid targeting and Cherenkov radiation response as well as a preparation method and application thereof, and belongs to the technical field of nano-material manufacturing and application. According to the invention, a photosensitive group nitrobenzyl is coupled with a hexadecyl DOX derivative (hydrophobicity is enhanced), the coupledproduct is embedded into a folic acid modified amphiphilic polymer (FA-PEG-PCL), the nano micelle NM/DOC is prepared, and the NM/DOC can utilize folic acid to target tumor cells. Furthermore, in theX-ray local radiotherapy process, the X-ray radiation is uniform, the photosensitive group-nitrobenzyl is broken through generated Cerenkov radiation, the hydrophilicity of DOX is improved, drug release is triggered, radiotherapy and chemotherapy are organically integrated, the specificity of chemotherapy drug action is enhanced through active targeting and response drug release of NM/DOC, and thetoxic and side effects on the human body are greatly reduced.

The invention discloses a measurement method and device for AB-BNCT mixed radiation field dose distribution. The measurement method comprises the steps that neutrons act with an optical fiber array togenerate first radiological fluorescence, and gamma acts with the optical fiber array to generate second radiological fluorescence and Cherenkov radiation; the first radiological fluorescence, the second radiological fluorescence and the Cerenkov radiation are transmitted to the sensor along the optical fiber; the first radiological fluorescence, the second radiological fluorescence and the Cherenkov radiation are sequentially converted into an electric signal and a digital signal, and the electric signal and the digital signal are transmitted to a computer; obtaining digital signals of radiofluorescence and Cherenkov radiation respectively generated by neutrons and gamma radiation by utilizing the difference between the optical fiber array and the interaction between the neutrons and thegamma radiation; and rotating the optical fiber array to obtain the digital signals of the radiofluorescence and the Cherenkov radiation at different angles. According to the invention, discrimination and quick measurement of the mixed radiation field are realized, and the method has an important value for nuclear technology application, especially medical application.