# CMS Notes

2021-12-17
12:01
 A semi-empirical model for preheater design to trigger CO$_2$ boiling for detector cooling / Baldinelli, Giorgio (INFN, Perugia) ; French, Thomas Anders (CERN) ; Bianchi, Francesco (INFN, Perugia) ; Daguin, Jerome (CERN) ; Onnela, Antti Tero Olavi (CERN) ; Tropea, Paola (CERN) The fluid properties of CO$_2$ make it an ideal medium for the cooling of tracking detectors in experiments at particle accelerators. Detectors such as the Compact Muon Solenoid Outer Tracker at CERN will be cooled to a nominal temperature of -35$^{\circ}$C with CO$_2$ cooling to ensure the longevity of the silicon sensors. [...] CMS-NOTE-2020-004; CERN-CMS-NOTE-2020-004.- Geneva : CERN, 2020 - 21 p. Fulltext: PDF;

2021-12-17
11:45
 Detailed results of the response of a CMS HGCAL silicon-pad electromagnetic calorimeter prototype to 20-300 GeV positrons. / Akchurin, Nural (Texas Tech.) CMS is designing a new high-granularity endcap calorimeter, HGCAL, to be installed later this decade. As part of this development work, a prototype system was extensively tested with beams at CERN's SPS in 2018. [...] CMS-NOTE-2021-009; CERN-CMS-NOTE-2021-009.- Geneva : CERN, 2021 - 37 p. Fulltext: PDF;

2021-12-17
11:45
 Influence of Surface Damage and Bulk Defects on the Interstrip Isolation of p-type Silicon Strip Sensors / Gosewisch, Jan-Ole (KIT, Karlsruhe, EKP) ; Dierlamm, Alexander Hermann (KIT, Karlsruhe, EKP) ; Nurnberg, Andreas Matthias (DESY) Silicon strip sensors of upcoming tracking detectors in high luminosity colliders usually consist of a p-doped bulk with n-type strip implants. The general consensus is that such a design requires an additional interstrip isolation structure such as a p-stop implant. If there is no additional implant between the strips, it is expected that the strip isolation will be insufficient. [...] CMS-NOTE-2021-002; CERN-CMS-NOTE-2021-002.- Geneva : CERN, 2020 - 20 p. Fulltext: PDF;

2021-12-17
11:45
 Report from Young Scientist Fora at LHC / Vami, Tamas Almos (Johns Hopkins U.) ; ATLAS ; CMS ; LHCb young scientists Half of each collaboration at LHC is composed of early career scientists (BSc, MSc, PhD students and PostDocs). To represent this demographic, young scientist committees were created at all LHC experiments. [...] CMS-NOTE-2020-006; CERN-CMS-NOTE-2020-006.- Geneva : CERN, 2020 - 9 p. Fulltext: PDF;

2021-12-17
11:39
 Experimental Study of Different Silicon Sensor Options for the Upgrade of the CMS Outer Tracker / Tracker Group of the CMS Collaboration /CMS Collaboration During the high-luminosity phase of the LHC (HL-LHC), planned to start around 2026, the accelerator is expected to deliver an instantaneous peak luminosity of up to $7.5\times10^{34}$~cm$^{-2}$s$^{-1}$. A total of $3000$~fb$^{-1}$ of integrated luminosity is foreseen to be delivered to the general purpose detectors ATLAS and CMS over a decade, thereby increasing the discovery potential of the LHC experiments significantly. The CMS detector will undergo a major upgrade for the HL-LHC, with entirely new tracking detectors consisting of an Outer Tracker and Inner Tracker. [...] CMS-NOTE-2019-007; CERN-CMS-NOTE-2019-007.- Geneva : CERN, 2019 - 35 p. Fulltext: PDF;

2021-10-22
19:28
 Selection of the silicon sensor thickness for the Phase-2 upgrade of the CMS Outer Tracker /CMS Tracker Group During the operation of the CMS experiment at the High-Luminosity LHC the silicon sensors of the Phase-2 Outer Tracker will be exposed to radiation levels that could potentially deteriorate their performance. Previous studies had determined that planar float zone silicon with n-doped strips on a p-doped substrate was preferred over p-doped strips on an n-doped substrate. [...] CMS-NOTE-2021-008; CERN-CMS-NOTE-2021-008.- Geneva : CERN, 2021 - 41 p. - Published in : JINST 16 (2021) P11028 Fulltext: PDF; Fulltext from publisher: PDF;

2021-09-21
16:28
 Performance of prototype GE1$\slash$1 chambers for the CMS muon spectrometer upgrade / The CMS Muon Group The high-luminosity phase of the Large Hadron Collider (HL-LHC) will result in ten times higher particle background than measured during the first phase of LHC operation. In order to fully exploit the highly-demanding operating conditions during HL-LHC, the Compact Muon Solenoid (CMS) Collaboration will use Gas Electron Multiplier (GEM) detector technology. [...] CMS-NOTE-2020-001; CERN-CMS-NOTE-2020-001.- Geneva : CERN, 2019 - 19 p. Fulltext: PDF;

2021-08-19
11:41
 FLUKA Run 2 simulation benchmarking with beam loss monitors in the CMS forward region / Kicsiny, Peter (CERN) The FLUKA simulation framework is a general purpose Monte Carlo software for nuclear physics applications. It is commonly used by the CMS collaboration to make estimates on radiation levels in the underground cavern and at specific detector locations. [...] CMS-NOTE-2021-007; CERN-CMS-NOTE-2021-007.- Geneva : CERN, 2021 - 19 p. Fulltext: PDF;

2021-07-21
18:49
 Position resolution with 25 $\mu$m pitch pixel sensors before and after irradiation / Ebrahimi, Aliakbar (PSI, Villigen) ; Feindt, Finn (Hamburg U.) ; Garutti, Erika (Hamburg U.) ; Gunnellini, Paolo (Hamburg U.) ; Hinzmann, Andreas Dominik (Hamburg U.) ; Niemeyer, Caroline (Hamburg U.) ; Pitzl, Daniel (DESY) ; Schwandt, Joern (Hamburg U.) ; Steinbrueck, Georg (Hamburg U.) ; Zoi, Irene (Hamburg U.) Pixelated silicon detectors are state-of-the-art technology to achieve precise tracking and vertexing at collider experiments, designed to accurately measure the hit position of incoming particles in high rate and radiation environments. The detector requirements become extremely demanding for operation at the High-Luminosity LHC, where up to 200 interactions will overlap in the same bunch crossing on top of the process of interest. [...] CMS-NOTE-2021-006; CERN-CMS-NOTE-2021-006.- Geneva : CERN, 2021 - 18 p. Fulltext: PDF;

2021-06-14
16:16
 Towards Common $t\bar{t}$ Monte-Carlo Settings for ATLAS and CMS / The ATLAS ; CMS Collaborations /ATLAS and CMS Collaborations Both ATLAS and CMS use POWHEG+PYTHIA8 Monte-Carlo simulations to model the $t\bar{t}$ process. A commonly agreed upon set of POWHEG and PYTHIA8 parameters is presented and compared to the nominal ATLAS and CMS settings. [...] CMS-NOTE-2021-005; CERN-CMS-NOTE-2021-005.- Geneva : CERN, 2021 - 19 p. Fulltext: PDF;