Operational experience, improvements, and performance of the CDF Run II silicon vertex detector

Abstract

The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb −1 of integrated luminosity of pp collisions at √ s = 1.96 TeV. The physics at CDF includes precise measurements of the masses of the top quark and W boson, measurement of CP violation and B s mixing, and searches for Higgs bosons and new physics signatures, all of which require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2-5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDF's physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance.

Indirect measurement ofsin2θW(MW) usingeAaltonen1, Amerio2, Amidei3 et al. 2013Phys. Rev. DSelf Cite1832701View full textAdd to dashboardCite

“…Detector coordinates are specified as ð det ; cm Þ, where det is the pseudorapidity relative to the detector center (z ¼ 0). The central charged-particle tracking detector (tracker) is a 3.1 m long, open-cell drift chamber [25] that radially extends from 0.4 to 1.4 m. Between the Tevatron beam pipe and the central tracker is a 2 m long silicon vertex tracker [26]. Both trackers are immersed in a 1.4 T axial magnetic field.…”

Study of orbitally excitedBmesons and evidence for a newBπresonance

“…The key components of the CDF II detector [25] for these measurements are the chargedparticle trajectory (tracking) subdetectors located in a uniform axial magnetic field of 1.4 T, together with the muon detectors. A single-sided silicon-strip detector mounted directly on the beam pipe at 1.5 cm radius and six layers of double-sided silicon strips extending to a radius of 22 cm [26] provide a resolution of approximately 40 μm on the impact parameter, defined as the distance between the interaction point and the trajectory of a charged particle, projected into the plane transverse to the beam. This includes a 32 μm contribution from the transverse beam size [26].…”

“…A single-sided silicon-strip detector mounted directly on the beam pipe at 1.5 cm radius and six layers of double-sided silicon strips extending to a radius of 22 cm [26] provide a resolution of approximately 40 μm on the impact parameter, defined as the distance between the interaction point and the trajectory of a charged particle, projected into the plane transverse to the beam. This includes a 32 μm contribution from the transverse beam size [26]. An open-cell drift chamber, which covers a radius range of 45 to 137 cm [27], allows precise measurement of the momentum of charged particles with a resolution of σðp T Þ=p 2 T ≈ 0.1%=ðGeV=cÞ.…”

Mass and lifetime measurements of bottom and charm baryons inpp¯collisions ats=1.96 Aaltonen1, Amerio2, Amidei3 et al. 2014Phys. Rev. DSelf Cite333220View full textAdd to dashboardCite

“…It measures charged-particle positions (hits) in the transverse view with respect to the beam, which is parallel to the z direction. A five-layer silicon detector (SVX II) surrounding L00 measures hits at radii of 2.5 to 10.6 cm [17]. Each of these layers provides a transverse measurement and a stereo measurement of 90°( three layers) or AE1.2°(two layers) with respect to the beam direction.…”