7 results about "Dose uniformity" patented technology

A food irradiation system comprising a plurality of compact linear accelerator systems is described herein. Each of the plurality of compact linear accelerator systems includes: a high energy particle beam source providing a particle beam up to 10 MeV; an emission target assembly configured to generate bremsstrahlung x-rays when impacted by particles of the particle beam; and a drift tube through which the particle beam passes on a path from the high-energy particle beam source to the emission target assembly. The emission target assembly is positioned at the distal end of the drift tube for direct impinging of the particle beam to generate bremsstrahlung x-rays in the directed radiation beam. Each of the plurality of compact linear accelerator systems is individually positioned such that the plurality of compact linear accelerator systems as a group provide directed radiation beam coverage for the total cumulative volume at a prescribed radiation dose level.

The invention discloses a wearable penile cancer individualized tissue compensation device which comprises a wearable frame, a tissue compensation assembly, a testis protective cover and an intelligent monitoring assembly. The wearing frame is connected with a fixing belt with a holding hole through a magic tape waistband; a liquid injection cavity is formed in a tubular flexible bag body of the tissue compensation assembly and is used for simulating a human tissue electron density elimination dose build-up effect; the testis protective cover is detachably installed on the inner side of the fixing band. An epoxy resin capsule of the intelligent monitoring assembly is integrated with a sensor and a wireless module. According to the device, the penis surface dose reaches nearly 100%, the displacement error of a target region is smaller than 3 mm, the dose uniformity is remarkably improved, and the testis stress is reduced to 4.8 goals; when the pressure and the temperature exceed the limit, the pressure is automatically relieved and an alarm is given, the flexible bag body adapts to the size of an individual, radiotherapy accuracy, radiation protection efficiency and wearing convenience are achieved, and the clinical problems of organ displacement, non-uniform dose and testis protection are solved.

Methods and systems for radiation treatment planning use objective function formulations to evaluate a proposed (candidate) radiation treatment plan, to determine whether or not clinical goals that are specified for treatment of a patient are satisfied by the plan. Dose distributions for a region of a target volume are generated. A value of an objective function formulation is determined. The value of the objective function formulation is a function of difference between a value that is based on a dose distribution and a value for a range that is associated with the treatment field corresponding to the dose distribution. In this manner, the uniformity of doses of individual treatment fields can be controlled. The value of the objective function formulation can be used in a process for optimizing dose distributions in the radiation treatment plan.

The invention discloses an immersed plasma energy and dose testing device, and relates to the field of semiconductor plasma injection process, in the device, a grid group and a first collector are sequentially arranged in an energy collection device at intervals, the grid group comprises N grids, and a voltage supply module provides corresponding target bias voltage for the grid group; forming a grading energy screening electric field; the first collector collects the screened plasma and converts and outputs a first electric signal; a second collector in the dose collection device collects the total number of plasmas in the device and outputs a second electric signal; and the conversion module gates one path of electric signal at any moment and converts and outputs a target voltage signal to the control module so as to determine the energy distribution and dose distribution of the plasma. According to the scheme, energy testing and dosage testing can be carried out at the same time, it is guaranteed that the ion energy distribution condition and the dosage uniformity condition are accurately monitored in the one-time plasma injection process, and wafer modification errors are reduced.

This invention proposes a method for optimizing the dose uniformity of laser interference lithography stitching based on Gaussian beam fitting, belonging to the field of ultra-precision micro / nano manufacturing technology. Addressing the stitching unevenness problem caused by beam distortion and finite boundary effects in large-area stepping interference lithography, this invention acquires actual interference light field images and performs global two-dimensional Gaussian fitting to accurately extract spot feature parameters. Based on this, a dose accumulation model under finite dot matrix scanning is constructed, and the optimal two-dimensional step displacement that can compensate for local interference troughs and macroscopic attenuation envelope is calculated through optimization. Simultaneously, an exposure dose constraint mechanism is introduced to limit the cumulative total light intensity within the development threshold range to prevent photoresist overexposure degradation caused by high overlap. Finally, the optimal parameters are output and used to control the positioning stage for precise exposure. This invention effectively overcomes the obvious gaps and energy distortion caused by traditional fixed-spacing stitching, achieving high-quality, seamless stitching manufacturing of large-area holographic gratings.

The application discloses an X-ray blood irradiation device calibration device and a calibration method. The calibration device comprises a detector, a detector host and a blood equivalent phantom. According to the target irradiation container, the blood equivalent phantom is selected and placed, the detector is connected with the blood equivalent phantom, the detector is moved to a reference point, the absorbed dose value of the reference point is read to calculate the indication error, the absorbed dose value of each measurement point is read to calculate the absorbed dose uniformity of the target irradiation container, and the reference points of each irradiation container are taken as measurement points, the values read by the detector are used to calculate the consistency of the absorbed dose values among the irradiation containers. The scheme realizes the measurement of dynamic blood irradiation dose, solves the problem that the existing X-ray blood irradiation device cannot accurately measure the irradiation dose and the irradiation dose uniformity, realizes the transmission of data without punching in the measurement chamber, the measurement result can be reproduced, and is more suitable for repeated measurement.

The invention discloses an X-ray irradiator which comprises a support and a control system, a high-voltage generator, a ray tube assembly, a cooling system and a self-shielding irradiation chamber which are installed on the support, the high-voltage generator is connected with the ray tube assembly, the cooling system is used for cooling the ray tube assembly, and the ray tube assembly is installed above the self-shielding irradiation chamber. A ray outlet of the ray tube assembly is aligned with a ray inlet in the upper wall of the self-shielding irradiation chamber, and a conical collimator and a flattening device are arranged at the ray outlet. Through the arrangement of the conical collimator and the flattening device, scattered rays are effectively shielded, meanwhile, the range of electron radiation can be limited so as to protect the outside of a target area from being irradiated, the energy spectrum distribution of X rays is improved, main beam attenuation is reduced, most of stray rays are filtered, the dose is relatively flat in an irradiation area, the dose uniformity is good, and the radiation efficiency is improved. When X-rays are used for irradiation, the radiation dose can be controlled, and better dose uniformity is provided.