Upgrading the ATLAS Experiment at the CERN LHC

随着希格斯玻色子的观测，未来在CERN大型强子对撞机上使用ATLAS的物理计划将成为人们关注的焦点。除了精确测量这种新发现的粒子的耦合和其他性质外，新的TeV尺度电弱物理稳定希格斯真空的动机仍然很强。未来的大型强子对撞机计划在最近的战略规划中被确认为欧洲粒子物理的首要任务，大型强子对撞机和ATLAS的未来运行是安全的。ATLAS探测器需要升级，以在未来几年以预期的不断增加的能量和速率运行，保持加拿大对ATLAS的参与包括加拿大参与ATLAS探测器升级计划。加拿大集团目前正专注于ATLAS的两个近期“第一阶段”升级：(I)建造、测试和安装用于新的Muon端盖“小轮子”的高速薄间隙腔(STGC)和(Ii)设计、组装、测试和安装用于液态氩量热计(LAR)触发器的升级的前端电子设备。这两个升级都是为了允许ATLAS在低轻子(介子和电子)的情况下运行，触发横向动量阈值，这对于研究希格斯粒子和寻找新的电弱尺度物理过程是必不可少的，例如超对称性、额外维度，或者更广泛地说，可以解释暗物质的性质并帮助稳定希格斯真空的物理过程。加拿大的sTGC计划涉及为ATLAS或建造三分之一的sTGC室。加拿大的三家工厂包括：(1)基于TRIUMF的阴极制备和碳/环氧喷涂设施，以确保腔室内壁电阻层的精确涂层；(2)基于Carleton的绕线和腔室组装设施，以完成气体和高压应用的四联体；(3)设在McGill的暗室宇宙射线测试设施，以确保在将其运往CERN之前，加拿大建造的暗室功能齐全。用于实验室建造和测试的基础设施的很大一部分是用2013年大赛NSERC RTI奖的资金购买的，以及建造原型舱的材料。大部分剩余的实验室基础设施，加上最初的暗室建筑材料，将在2014年的比赛中用NSERC RTI申请的资金购买，使我们能够按照ATLAS要求的时间表增加我们的暗室生产设施。加拿大的Lar Electronics项目包括为加拿大制造的强子端盖热量计(HEC)设计、制作原型和制造新的前端机箱底板。我们还将为该项目设计、制造和测试模拟电子设备的几个部件，并为电路板购买ADC组件。2013年NSERC RTI奖励资金将用于初始基板设计和部件测试，包括验证其中子辐照耐受性。在NSERC 2014 SAPES RTI竞赛中申请的资金将用于建造和测试HEC底板的全尺寸原型。在2014-2015财年，加拿大需要在此RTI申请中申请资金，以继续在ATLAS升级方面发挥领导作用。在即将到来的比赛中，完成项目所需的大部分资本和劳动力成本将由加拿大创新基金会支付。

With the observation of a Higgs boson, the future physics program with ATLAS at the CERN Large Hadron Collider is coming into focus. In addition to precise measurements of the couplings and other properties of this newly discovered particle, the motivation for new TeV-scale electroweak physics to stabilize the Higgs vacuum remains strong. The future LHC program was affirmed as the top priority of European particle physics in recent strategic planning, and the future of LHC and ATLAS operations is secure. The ATLAS detector requires upgrades to operate at the increasing energy and rates expected in the coming years, and maintaining Canadian involvement in ATLAS includes Canadian participation in the ATLAS detector upgrade program. Canadian groups are currently focusing on two near-term “phase 1” ATLAS upgrades: (i) construction, testing and installation of high-rate thin gap chambers (sTGC) for the new muon end cap “small wheel” and (ii) design, assembly, testing and installation of upgraded front-end electronics for the liquid argon calorimeter (LAr) trigger. Both of these upgrades are designed to allow ATLAS operation with low lepton (muon and electron) trigger transverse momentum thresholds which are essential for the studies of the Higgs and searches for new electroweak-scale physics processes such as supersymmetry, extra dimensions, or more generally the physics that could explain the nature of dark matter and help stabilize the Higgs vacuum. The Canadian sTGC program involves building one third of the sTGC chambers planned for ATLAS, or 64 “quadruplets”. The three Canadians sites include: (1) TRIUMF-based cathode preparation and carbon/epoxy spray facility to ensure precise resistive layer coating of the chamber interior walls; (2) Carleton-based wire winding and chamber assembly facility to complete the quadruplets for gas and high-voltage application; (3) McGill-based chamber cosmic ray testing facility to ensure the Canadian-built chambers are fully functional before shipping them to CERN. A significant part of the laboratory infrastructure for chamber construction and testing is being purchased with the funds from the NSERC RTI award from the 2013 competition, along with material for prototype chamber construction. Most of the remainder of the laboratory infrastructure, plus initial chamber construction materials, would be purchased with funds from the NSERC RTI request in the 2014 competition, allowing us to ramp up our chamber production facilities on the timescale required by ATLAS. The Canadian LAr Electronics program involves designing, prototyping and building new front-end crate baseplanes for the Canadian-built Hadronic Endcap Calorimeter (HEC). We will also design, build and test several parts of the analogue electronics for the project, and purchase ADC components for the boards. The 2013 NSERC RTI award funds are being used for initial baseplane design and component testing, including verifying their neutron irradiation tolerance. The funds requested in the NSERC 2014 SAPES RTI competition would be used to construct and test a full-scale prototype of the HEC baseplane. The funds requested in this RTI application are required in Fiscal Year 2014-2015 for continued Canadian leadership in ATLAS upgrades. The majority of the capital and labour costs for project completion will be requested from the Canada Foundation for Innovation in the upcoming competition.