Electromagnetic fields and beam dynamics simulation for the superstructure of TESLA linear collider considering field asymmetry caused by HOM and power couplers

Some features of accelerating section field computation presented by the development of power and HOM couplers for TESLA linear collider are considered. The devices mentioned produce electromagnetic field asymmetry in the beam area, thus causing transverse kick. For this kick and its influence on beam under acceleration parameters estimation the dynamics modelling calculations were done. 3D-simulation code MAFIA was used for field computation. These data were further used in beam dynamics calculations by means of TRMTrace code. Standing wave mode was simulated while considering HOM couplers, and travelling wave in case of power couplers. Transverse kicks and focussing forces are calculated for one HOM coupler design and two coaxial FM couplers

Measurement of electrodynamics characteristics of higher order modes for harmonic cavity at 2400 MHz

In the frameworks of the High Luminosity Large Hadron Collider (HL-LHC) upgrade program an application of additional superconducting harmonic cavities operating at 800 MHz is currently under discussion. As a possible candidate, an assembly of two cavities with grooved beam pipes connected by a drift tube and housed in a common cryomodule, was proposed. In this article we discuss measurements of loaded Q-factors of higher order modes (HOM) performed on a scaled aluminium single cell cavity prototype with the fundamental frequency of 2400 MHz and on an array of two such cavities connected by a narrow beam pipe. The measurements were performed for the system with and without the matching load in the drift tube.

Design, Characteristics and Dynamic Properties of Mobile Plunger based Frequency Tuning System for Coaxial Half Wave Resonators

The practical realization of a prototype of the frequency tuning system FTS for coaxial half wave cavities HWR for the Nuclotron based Ion Collider fAcility NICA in jector is presented. The impact of FTS on electromagnetic parameters of copper HWR prototype is experimentally stud ied and discussed. The most important parameters like tun ing range, tuning sensitivity, the dependence of the resonant frequency on the position of the plungers are estimated. The effective operation algorithms of the proposed FTS are dis cussed and analyzed. The dynamic characteristics of FTS are investigated and showed the ability to adjust the frequency with an accuracy of about 70 H

Результаты современных радиационно-гигиенических обследований приграничных с Республикой Беларусь населенных пунктов Брянской области Российской Федерации. Часть 1: Характеристика населенных пунктов

This study presents results of radiation-hygienic surveys of the Bryansk Oblast settlements bordering the Republic of Belarus. The data were obtained in the course of implementation of measures of the “Program of joint activities of Russia and Belarus within the framework of the Union State for the protection of the population and rehabilitation of the territories affected by the Chernobyl NPP accident” in 2019–2022. The first part of the study presents a general characteristic of the current state of the problem of returning the residents of radioactively contaminated territories to normal living conditions and provides information on the settlements of the surveyed region. The modern demographic composition of the population is considered; the structure of private subsidiary plots is investigated. The results described in this part of the study indicate the main ways, which are relevant for the formation of the internal exposure dose of the public at the current stage of the radiation accident.В статье приводятся результаты радиационно-гигиенических обследований приграничных с Республикой Беларусь населенных пунктов Брянской области, полученные в 2019–2022 гг. в ходе реализации мероприятий «Программы совместной деятельности России и Беларуси в рамках Союзного государства по защите населения и реабилитации территорий, пострадавших в результате катастрофы на Чернобыльской АЭС». В первой части статьи дана общая характеристика современного состояния проблемы возвращения жителей радиоактивно загрязненных территорий к условиям нормальной жизнедеятельности и приводятся сведения о населенных пунктах обследованного региона. Рассмотрен современный демографический состав населения, исследована структура личных подсобных хозяйств. На основании результатов, описанных в данной части публикации, выделены основные пути формирования дозы внутреннего облучения населения, актуальные для современного этапа радиационной аварии

Higher Order Modes Simulation and Measurements for 2400 MHz Cavity

In the frameworks of the High Luminosity LHC upgrade program an application of additional harmonic cavities operating at multiples of the main RF system frequency of 400 MHz is currently under discussion. The 800 MHz superconducting cavities with grooved beam pipes were suggested as one of the design options. A scaled aluminum prototype with a frequency of the operational mode of 2400 MHz was manufactured for testing the results of simulations. The load reflection coefficient measurements were performed as well as the Qload measurements for cavities with the load. Here we discuss the prototype design and report the obtained measurement results