Two drift tubes (DTs) chambers of the CMS muon barrel system were exposed to a 40
MHz bunched muon beam at the CERN SPS, and for the first time the whole CMS Level-1 DTs-based trigger system chain ...was tested. Data at different energies and inclination angles of the incident muon beam were collected, as well as data with and without an iron absorber placed between the two chambers, to simulate the electromagnetic shower development in CMS. Special data-taking runs were dedicated to test for the first time the Track Finder system, which reconstructs track trigger candidates by performing a proper matching of the muon segments delivered by the two chambers. The present paper describes the results of these measurements.
Fine synchronization of the CMS muon drift tubes local trigger Aldaya, M.; Amapane, N.; Battilana, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2006, Letnik:
564, Številka:
1
Journal Article
Recenzirano
The drift tubes based CMS barrel muon trigger, which uses self-triggering arrays of drift tubes, is able to perform the identification of the muon parent bunch crossing using a rather sophisticated ...algorithm. The identification is unique only if the trigger chain is correctly synchronized. Some beam test time was devoted to take data useful to investigate the synchronization of the trigger electronics with the machine clock. Possible alternatives were verified and the dependence on muon track properties was studied.
Bunched beam test of the CMS drift tubes local muon trigger Arce, P.; Bellato, M.; Benettoni, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2004, Letnik:
534, Številka:
3
Journal Article
Recenzirano
The 40
MHz bunched muon beam set up at CERN was used in May 2003 to make a full test of the drift tubes local muon trigger. The main goal of the test was to prove that the integration of the various ...devices located on a muon chamber was adequately done both on the hardware and software side of the system. Furthermore the test provided complete information about the general performance of the trigger algorithms in terms of efficiency and noise. Data were collected with the default configuration of the trigger devices and with several alternative configurations at various angles of incidence of the beam. Tests on noise suppression and di-muon trigger capability were performed.
Test beam analysis of the first CMS drift tube muon chamber Albajar, C.; Amapane, N.; Arce, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2004, Letnik:
525, Številka:
3
Journal Article
Recenzirano
In October 2001 the first produced CMS Barrel Drift Tube (DT) Muon Chamber was tested at the CERN Gamma Irradiation Facility (GIF) using a muon beam. A Resistive Plate Chamber (RPC) was attached to ...the top of the DT chamber, and, for the first time, both detectors were operated coupled together. The performance of the DT chamber was studied for several operating conditions, and for gamma rates similar to the ones expected at LHC. In this paper we present the data analysis; the results are considered fully satisfactory.
To sustain and extend its discovery potential, the Large Hadron Collider (LHC) will undergo a major upgrade in the coming years, referred to as High Luminosity LHC (HLLHC), aimed to increase its ...instantaneous luminosity, 5 times larger than the designed limit, and, consequently leading to high levels of radiation, with the goal to collect 10 times larger the original designed integrated luminosity. The drift tube chambers (DT) of CMS muon detector system is built to proficiently measure and trigger on muons in the harsh radiation environment expected during the HL-LHC era. Ageing studies are performed at the CERNs gamma ray irradiation facility (GIF++) by measuring the muon hit efficiency of these detectors at various LHC operation conditions. One such irradiation campaign was started in October 2017, when a spare MB2 chamber moved inside the bunker and irradiated at lower acceleration factors. Two out of twelve layers of the DT chamber were operated while being irradiated with the radioactive source and then their muon hit efficiency was calculated in coincidence with other ten layers which were kept on the standby. The chamber absorbed an integrated dose equivalent to two times the expected integrated luminosity of the HL-LHC. Investigation on the outgassing of cell materials and of the gas components used at the GIF++ are underway and strategies to mitigate the aging effects are also being developed. The effect of radiation on the performance of DT chamber and its impact on the overall muon reconstruction efficiency expected during the HL-LHC are presented.
Firstly we amend for buildings the traditional term of "Surface Area to Volume Ratio", "Coefficient of Susceptibility", or "Form Factor" (FF= A/V) for short, formulating a Weighted Form Factor (FF*= ...A*/V) in which the surface areas of the geometric envelope are affected by the corresponding thermal transmission coefficients. This parameter is shown to be equal to the unitary and specific flow of transmission heat through that envelope, and it is an adequate tool to compare the preliminary efficacy of different design solutions on homogeneous basis.
Then it is unveiled a Geometrical Law (formalised in an Identity Theorem), that establishes that for certain typologies of elongated buildings (e.g. Annular types of building, and also long Blocks and Towers), the Form Factor of their three-dimensional shape is identical to the Form Factor of the mean cross section or "Perimeter to Section Area Ratio". The dimensional reduction from 3D to 2D implies that many problems of analysis and design become extremely easy in a variety of fields: urban planning, building projects, and general morphology.
Thirdly the Practical Implications are exposed: applied for example to the task of achieving a greater energy efficiency (by thermal transfer) of long building blocks and towers, there is no need for considering the whole exterior envelope; it is enough to ensure the optimisation of the cross section (in the tower is the floor plan), in the most adequate, compact and large 2D figure, and the most insulated perimeter for it. To achieve those goals, we propose new criteria and methodology, and give hints for a two-dimensional morpho-thermal model.
Using these procedures, design tasks not restricted by volume, can focus only on the section of elongated buildings, and their plan layouts can be freely adapted to what is more appropriate in relation to other important aspects: street guidelines, sunlight & wind orientation, lighting, etc.
The Compact Muon Solenoid (CMS) experiment prepares its Phase-2 upgrade for the high-luminosity era of the LHC operation (HL-LHC). Due to the increase of occupancy, trigger latency and rates, the ...full electronics of the CMS Drift Tube (DT) chambers will need to be replaced. In the new design, the time bin for the digitization of the chamber signals will be of around 1 ns, and the totality of the signals will be forwarded asynchronously to the service cavern at full resolution. The new backend system will be in charge of building the trigger primitives of each chamber. These trigger primitives contain the information at chamber level about the muon candidates position, direction, and collision time, and are used as input in the L1 CMS trigger. The added functionalities will improve the robustness of the system against ageing. An algorithm based on analytical solutions for reconstructing the DT trigger primitives, called Analytical Method, has been implemented both as a software C++ emulator and in firmware. Its performance has been estimated using the software emulator with simulated and real data samples, and through hardware implementation tests. Measured efficiencies are 96 to 98% for all qualities and time and spatial resolutions are close to the ultimate performance of the DT chambers. A prototype chain of the HL-LHC electronics using the Analytical Method for trigger primitive generation has been installed during Long Shutdown 2 of the LHC and operated in CMS cosmic data taking campaigns in 2020 and 2021. Results from this validation step, the so-called Slice Test, are presented.
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