Введение
Концепция линейного ускорителя частиц
The Compact Linear Collider (CLIC) is a concept for a future linear particle accelerator that aims to explore the next energy frontier. CLIC would collide electrons with positrons and is currently the only mature option for a multi TeV linear collider. The accelerator would be between long, more than ten times longer than the existing Stanford Linear Accelerator (SLAC) in California, US. CLIC is proposed to be built at CERN, across the border between France and Switzerland near Geneva, with first beams starting by the time the Large Hadron Collider (LHC) has finished operations around 2035. complemented by an updated energy staging scenario in 2016. Additional detailed studies of the physics case for CLIC, an advanced design of the accelerator complex and the detector, as well as numerous R&D results are summarised in a recent series of CERN Yellow Reports. However, the LHC can only partially answer questions about the true nature of this particle, such as its composite/fundamental nature, coupling strengths, and possible role in an extended electroweak sector. The 380 GeV stage of CLIC allows, for example, accurate model independent measurements of Higgs boson couplings to fermions and bosons through the Higgsstrahlung and WW fusion production processes. The second and third stages give access to phenomena such as the top Yukawa coupling, rare Higgs decays and the Higgs self coupling. The CLIC linear collider plans to have an extensive top quark physics programme. A major aim of this programme would be a threshold scan around the top quark pair production threshold (~350 GeV) to precisely determine the mass and other significant properties of the top quark. For this scan, CLIC currently plans to devote 10% of the running time of the first stage, collecting 100 fb−1. Direct pair production of particles up to a mass of 1.5 TeV, and single particle production up to a mass of 3 TeV is possible at CLIC. Due to the clean environment of electron positron colliders, CLIC would be able to measure the properties of these potential new particles to a very high precision. On the other hand, this research has also indicated that quantum gravity or perturbative quantum field theory will become strongly coupled before 1 PeV, leading to other new physics in the TeVs. The high accelerating gradient and the target BDR value (3 × 10−7 pulse−1m−1) drive most of the beam parameters and machine design. {| class="wikitable"
|+<small> Key parameters of the CLIC energy stages. [[File:CLIC complex 3tev woarrows. jpg|alt=|thumb|400x400px|Overall layout of the CLIC accelerator complex for the 3 TeV stage, in which one can identify the two Drive Beam and two Main Beam injector complexes The positrons for the main beam are produced by sending a 5 GeV electron beam on a tungsten target. After an initial acceleration up to 2.86 GeV, both electrons and positrons enter damping rings for emittance reduction by radiation damping. Both beams are then further accelerated to 9 GeV in a common booster linac. Long transfer lines transport the two beams to the beginning of the main linacs where they are accelerated up to 1.5 TeV before going into the Beam Delivery System (BDS), which squeezes and brings the beams into collision. The two beams collide at the IP with 20 mrad crossing angle in the horizontal plane. These facilities provide the RF power and infrastructure required for the conditioning and verification of the performance of CLIC accelerating structures, and other X band based projects. Additional X band high gradient tests are being carried out at the NEXTEF facility at KEK and at SLAC, a new test stand is being commissioned at Tsinghua University and further test stands are being constructed at INFN Frascati and SINAP in Shanghai.
Компактный линейный коллайдер (CLIC) – это концепция будущего линейного ускорителя частиц, направленная на исследование следующего энергетического рубежа. CLIC предназначен для столкновения электронов с позитронами и в настоящее время является единственным зрелым вариантом для линейного коллайдера с энергией в несколько ТэВ. Ускоритель будет значительно длиннее – более чем в десять раз длиннее существующего линейного ускорителя Стэнфорда (SLAC) в Калифорнии, США. Предлагается построить CLIC в CERN, на границе между Францией и Швейцарией вблизи Женевы, с запуском первых пучков после завершения работы Большого адронного коллайдера (LHC) примерно в 2035 году, дополненного обновленным сценарием поэтапного увеличения энергии в 2016 году. Дополнительные подробные исследования физического обоснования CLIC, передовая конструкция ускорительного комплекса и детектора, а также многочисленные результаты исследований и разработок (НИОКР) обобщены в недавней серии «Желтых отчетов» CERN. Однако LHC может лишь частично ответить на вопросы об истинной природе этой частицы, такие как ее композитный или фундаментальный характер, константы связи и возможная роль в расширенном электрослабом секторе. Например, этап CLIC с энергией 380 ГэВ позволит провести точные, не зависящие от модели, измерения связей бозона Хиггса с фермионами и бозонами посредством процессов Higgsstrahlung и WW-слияния. Вторая и третья стадии обеспечат доступ к таким явлениям, как связь Юкавы верхнего кварка, редкие распады Хиггса и самодействие Хиггса. Линейный коллайдер CLIC планирует реализовать обширную программу изучения физики верхнего кварка. Основной целью этой программы станет сканирование порога производства пар верхних кварков (~350 ГэВ) для точного определения массы и других важных свойств верхнего кварка. Для этого сканирования CLIC планирует выделить 10% времени работы первого этапа, накопив 100 фб−1. На CLIC возможна прямая парная выработка частиц с массой до 1,5 ТэВ и выработка одиночных частиц с массой до 3 ТэВ. Благодаря чистой среде электрон-позитронных коллайдеров CLIC сможет измерять свойства этих потенциальных новых частиц с очень высокой точностью. С другой стороны, эти исследования также показали, что квантовая гравитация или возмутительная квантовая теория поля станут сильно взаимодействующими при энергиях выше 1 ПэВ, что приведет к появлению новой физики в диапазоне ТэВ. Высокий градиент ускорения и целевое значение BDR (3 × 10−7 импульс−1м−1) определяют большинство параметров пучка и конструкцию ускорителя.
The Compact Linear Collider (CLIC) is a concept for a future linear particle accelerator that aims to explore the next energy frontier. CLIC would collide electrons with positrons and is currently the only mature option for a multi TeV linear collider. The accelerator would be between long, more than ten times longer than the existing Stanford Linear Accelerator (SLAC) in California, US. CLIC is proposed to be built at CERN, across the border between France and Switzerland near Geneva, with first beams starting by the time the Large Hadron Collider (LHC) has finished operations around 2035. complemented by an updated energy staging scenario in 2016. Additional detailed studies of the physics case for CLIC, an advanced design of the accelerator complex and the detector, as well as numerous R&D results are summarised in a recent series of CERN Yellow Reports. However, the LHC can only partially answer questions about the true nature of this particle, such as its composite/fundamental nature, coupling strengths, and possible role in an extended electroweak sector. The 380 GeV stage of CLIC allows, for example, accurate model independent measurements of Higgs boson couplings to fermions and bosons through the Higgsstrahlung and WW fusion production processes. The second and third stages give access to phenomena such as the top Yukawa coupling, rare Higgs decays and the Higgs self coupling. The CLIC linear collider plans to have an extensive top quark physics programme. A major aim of this programme would be a threshold scan around the top quark pair production threshold (~350 GeV) to precisely determine the mass and other significant properties of the top quark. For this scan, CLIC currently plans to devote 10% of the running time of the first stage, collecting 100 fb−1. Direct pair production of particles up to a mass of 1.5 TeV, and single particle production up to a mass of 3 TeV is possible at CLIC. Due to the clean environment of electron positron colliders, CLIC would be able to measure the properties of these potential new particles to a very high precision. On the other hand, this research has also indicated that quantum gravity or perturbative quantum field theory will become strongly coupled before 1 PeV, leading to other new physics in the TeVs. The high accelerating gradient and the target BDR value (3 × 10−7 pulse−1m−1) drive most of the beam parameters and machine design. {| class="wikitable"
|+<small> Key parameters of the CLIC energy stages. [[File:CLIC complex 3tev woarrows. jpg|alt=|thumb|400x400px|Overall layout of the CLIC accelerator complex for the 3 TeV stage, in which one can identify the two Drive Beam and two Main Beam injector complexes The positrons for the main beam are produced by sending a 5 GeV electron beam on a tungsten target. After an initial acceleration up to 2.86 GeV, both electrons and positrons enter damping rings for emittance reduction by radiation damping. Both beams are then further accelerated to 9 GeV in a common booster linac. Long transfer lines transport the two beams to the beginning of the main linacs where they are accelerated up to 1.5 TeV before going into the Beam Delivery System (BDS), which squeezes and brings the beams into collision. The two beams collide at the IP with 20 mrad crossing angle in the horizontal plane. These facilities provide the RF power and infrastructure required for the conditioning and verification of the performance of CLIC accelerating structures, and other X band based projects. Additional X band high gradient tests are being carried out at the NEXTEF facility at KEK and at SLAC, a new test stand is being commissioned at Tsinghua University and further test stands are being constructed at INFN Frascati and SINAP in Shanghai.
Ключевые параметры энергетических стадий CLIC.
The Compact Linear Collider (CLIC) is a concept for a future linear particle accelerator that aims to explore the next energy frontier. CLIC would collide electrons with positrons and is currently the only mature option for a multi TeV linear collider. The accelerator would be between long, more than ten times longer than the existing Stanford Linear Accelerator (SLAC) in California, US. CLIC is proposed to be built at CERN, across the border between France and Switzerland near Geneva, with first beams starting by the time the Large Hadron Collider (LHC) has finished operations around 2035. complemented by an updated energy staging scenario in 2016. Additional detailed studies of the physics case for CLIC, an advanced design of the accelerator complex and the detector, as well as numerous R&D results are summarised in a recent series of CERN Yellow Reports. However, the LHC can only partially answer questions about the true nature of this particle, such as its composite/fundamental nature, coupling strengths, and possible role in an extended electroweak sector. The 380 GeV stage of CLIC allows, for example, accurate model independent measurements of Higgs boson couplings to fermions and bosons through the Higgsstrahlung and WW fusion production processes. The second and third stages give access to phenomena such as the top Yukawa coupling, rare Higgs decays and the Higgs self coupling. The CLIC linear collider plans to have an extensive top quark physics programme. A major aim of this programme would be a threshold scan around the top quark pair production threshold (~350 GeV) to precisely determine the mass and other significant properties of the top quark. For this scan, CLIC currently plans to devote 10% of the running time of the first stage, collecting 100 fb−1. Direct pair production of particles up to a mass of 1.5 TeV, and single particle production up to a mass of 3 TeV is possible at CLIC. Due to the clean environment of electron positron colliders, CLIC would be able to measure the properties of these potential new particles to a very high precision. On the other hand, this research has also indicated that quantum gravity or perturbative quantum field theory will become strongly coupled before 1 PeV, leading to other new physics in the TeVs. The high accelerating gradient and the target BDR value (3 × 10−7 pulse−1m−1) drive most of the beam parameters and machine design. {| class="wikitable"
|+<small> Key parameters of the CLIC energy stages. [[File:CLIC complex 3tev woarrows. jpg|alt=|thumb|400x400px|Overall layout of the CLIC accelerator complex for the 3 TeV stage, in which one can identify the two Drive Beam and two Main Beam injector complexes The positrons for the main beam are produced by sending a 5 GeV electron beam on a tungsten target. After an initial acceleration up to 2.86 GeV, both electrons and positrons enter damping rings for emittance reduction by radiation damping. Both beams are then further accelerated to 9 GeV in a common booster linac. Long transfer lines transport the two beams to the beginning of the main linacs where they are accelerated up to 1.5 TeV before going into the Beam Delivery System (BDS), which squeezes and brings the beams into collision. The two beams collide at the IP with 20 mrad crossing angle in the horizontal plane. These facilities provide the RF power and infrastructure required for the conditioning and verification of the performance of CLIC accelerating structures, and other X band based projects. Additional X band high gradient tests are being carried out at the NEXTEF facility at KEK and at SLAC, a new test stand is being commissioned at Tsinghua University and further test stands are being constructed at INFN Frascati and SINAP in Shanghai.
Позитроны для основного пучка производятся путем направления пучка электронов с энергией 5 ГэВ на вольфрамовую мишень. После первоначального ускорения до 2,86 ГэВ электроны и позитроны поступают в демпферные кольца для уменьшения эмиттанса за счет радиационного демпфирования. Затем оба пучка ускоряются до 9 ГэВ в общем бустере. Длинные линии переноса транспортируют два пучка к началу основных линаков, где они ускоряются до 1,5 ТэВ, прежде чем попасть в систему доставки пучка (BDS), которая сжимает и направляет пучки на столкновение. Два пучка сталкиваются в точке взаимодействия (IP) под углом пересечения 20 мрад в горизонтальной плоскости. Эти установки обеспечивают ВЧ-мощность и инфраструктуру, необходимые для подготовки и проверки характеристик ускоряющих структур CLIC и других проектов на основе X-диапазона. Дополнительные испытания на высоком градиенте в X-диапазоне проводятся на объекте NEXTEF в KEK и в SLAC, новый испытательный стенд вводится в эксплуатацию в Университете Цинхуа, а дополнительные стенды строятся в INFN Frascati и SINAP в Шанхае.
The Compact Linear Collider (CLIC) is a concept for a future linear particle accelerator that aims to explore the next energy frontier. CLIC would collide electrons with positrons and is currently the only mature option for a multi TeV linear collider. The accelerator would be between long, more than ten times longer than the existing Stanford Linear Accelerator (SLAC) in California, US. CLIC is proposed to be built at CERN, across the border between France and Switzerland near Geneva, with first beams starting by the time the Large Hadron Collider (LHC) has finished operations around 2035. complemented by an updated energy staging scenario in 2016. Additional detailed studies of the physics case for CLIC, an advanced design of the accelerator complex and the detector, as well as numerous R&D results are summarised in a recent series of CERN Yellow Reports. However, the LHC can only partially answer questions about the true nature of this particle, such as its composite/fundamental nature, coupling strengths, and possible role in an extended electroweak sector. The 380 GeV stage of CLIC allows, for example, accurate model independent measurements of Higgs boson couplings to fermions and bosons through the Higgsstrahlung and WW fusion production processes. The second and third stages give access to phenomena such as the top Yukawa coupling, rare Higgs decays and the Higgs self coupling. The CLIC linear collider plans to have an extensive top quark physics programme. A major aim of this programme would be a threshold scan around the top quark pair production threshold (~350 GeV) to precisely determine the mass and other significant properties of the top quark. For this scan, CLIC currently plans to devote 10% of the running time of the first stage, collecting 100 fb−1. Direct pair production of particles up to a mass of 1.5 TeV, and single particle production up to a mass of 3 TeV is possible at CLIC. Due to the clean environment of electron positron colliders, CLIC would be able to measure the properties of these potential new particles to a very high precision. On the other hand, this research has also indicated that quantum gravity or perturbative quantum field theory will become strongly coupled before 1 PeV, leading to other new physics in the TeVs. The high accelerating gradient and the target BDR value (3 × 10−7 pulse−1m−1) drive most of the beam parameters and machine design. {| class="wikitable"
|+<small> Key parameters of the CLIC energy stages. [[File:CLIC complex 3tev woarrows. jpg|alt=|thumb|400x400px|Overall layout of the CLIC accelerator complex for the 3 TeV stage, in which one can identify the two Drive Beam and two Main Beam injector complexes The positrons for the main beam are produced by sending a 5 GeV electron beam on a tungsten target. After an initial acceleration up to 2.86 GeV, both electrons and positrons enter damping rings for emittance reduction by radiation damping. Both beams are then further accelerated to 9 GeV in a common booster linac. Long transfer lines transport the two beams to the beginning of the main linacs where they are accelerated up to 1.5 TeV before going into the Beam Delivery System (BDS), which squeezes and brings the beams into collision. The two beams collide at the IP with 20 mrad crossing angle in the horizontal plane. These facilities provide the RF power and infrastructure required for the conditioning and verification of the performance of CLIC accelerating structures, and other X band based projects. Additional X band high gradient tests are being carried out at the NEXTEF facility at KEK and at SLAC, a new test stand is being commissioned at Tsinghua University and further test stands are being constructed at INFN Frascati and SINAP in Shanghai.
Слои детектора
CLICdet состоит из четырех основных слоев с увеличивающимся радиусом: вершинный и трековый детектор, калориметры, соленоидный магнит и мюонный детектор. Для обеспечения эффективного воздушного охлаждения необходимо снизить среднее энергопотребление кремниевых датчиков в вершинном детекторе. Поэтому эти датчики будут работать по схеме импульсного питания на основе тока, переключаясь из состояния высокого энергопотребления в состояние низкого энергопотребления, когда это возможно, в соответствии с частотой пересечения пучков 50 Гц.
Статус
По состоянию на 2017 год, приблизительно два процента годового бюджета CERN инвестируются в разработку технологий CLIC. Первый этап CLIC длиной около 5 км в настоящее время оценивается в шесть миллиардов швейцарских франков, а также рассматривается статус проектов ускорителя и детектора CLIC. Обновление ESPP – это общеевропейский процесс, который, как ожидается, завершится в мае 2020 года публикацией стратегического документа. Подробная информация о проекте CLIC доступна в "Желтых отчетах" CERN, о потенциале CLIC для исследований новой физики, плане реализации проекта CLIC и технологиях детекторов для CLIC. Обзор представлен в сводном отчете CLIC за 2018 год.