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The D0 Run II luminosity monitor

Description: The D0 Run II Luminosity Monitor consists of plastic scintillation detectors with fine-mesh photomultiplier readout that cover the range 2.7 < {vert_bar}{eta}{vert_bar} < 4.4 in pseudorapidity. The detector is designed to provide a precise measurement of the rate for non-diractive inelastic collisions that is used to calculate the Tevatron luminosity at D0. Excellent time-of- ight resolution allows a clean separation between beam-beam interactions and the prin- cipal background from beam halo. In addition, timing is used to measure the position of the primary interaction vertex and to detect multiple interactions. Accurate correction for multiple proton-antiproton interactions in a single beam crossing is essential for an accurate luminosity determination. Associated electronics provide a single- interaction trigger term for the D0 Level 1 trigger, and readout of the photomultiplier timing and pulse-height measurements.
Date: December 1, 1998
Creator: Miao, Chyi-Chang

D0 search for new phenomena

Description: Presented here are the results from three searches for non-standard model particles using approximately 13 pb{sup {minus}1} of data taken with the D0 detector at Fermilab`s Tevatron, a p{bar p} collider operating at center-of-mass energy {radical}s=1.8 TeV. A heavy right-handed W, predicted by left-right symmetric theories, is excluded at 95% confidence level with mass between 200 GeV/c{sup 2} and 540 GeV/c{sup 2}, for a right-handed neutrino mass less than 100 GeV/c{sup 2}, regardless of the decay-properties of the neutrino, and assuming the W{sub R}`s couplings and C-K-M matrix are the same as the standard model W. Stricter limits are given on the right-handed neutrino mass for W{sub R} masses near the upper limit, and for specific assumptions on the right-handed neutrino decay modes. A 95% confidence-level limit on the cross-section p{bar p} {yields} W{sub 1}Z{sub 2} {yields} 3 leptons, where {sub 1}, is the lightest supersymmetric partner of the charged vector bosom and charged higgs and Z{sub 2} is the second lightest supersymmetric partner of the Z, {gamma}, and neutral higgs, ranging from 3 pb for M{sub w1}, =45 GeV/c{sup 2} to 1 pb for M{sub W1}=100 GeV/c{sup 2} is presented, assuming mass relations between the supersymmetric particles predicted by a popular supergravity inspired model. Third, a 95% confidence-level limit on the mass of the supersymmetric partner of the gluon of 144 GeV/c{sup 2}, if the supersymmetric partner of the quarks are very heavy, or 212 GeV/c{sup 2}, if they have equal masses, is presented within the framework of the same popular model.
Date: May 1, 1995
Creator: Eno, S.

D0 search for the Higgs boson in multijet events

Description: We present two searches for the Higgs boson in {radical}s = 1.96 TeV p{bar p} collisions using data taken with the D0 detector during Run II of the Fermilab Tevatron collider. The first study is a search for neutral Higgs bosons produced in association with bottom quarks. The cross sections for these processes are enhanced in many extensions of the standard model (SM), such as in its minimal supersymmetric extension at large tan {beta}. The results of our analysis agree with expectations from the SM, and we use our measurements to set upper limits on the production of neutral Higgs bosons in the mass range of 90 to 150 GeV. The second study is a search for the standard model Higgs boson produced in association with the Z boson.We study the p{bar p} {yields} ZH {yields} {nu}{bar {nu}}b{bar b} channel, which is one of the most sensitive ways to search for light Higgs bosons at the Tevatron. We select multijet events with large imbalance in transverse momentum and two b-tagged jets. Then we search for a peak in invariant mass distribution of two b-tagged jets. After subtracting the backgrounds, we set the 95% C.L. upper limits on the {sigma}(p{bar p} {yields} ZH {yields} {nu}{bar {nu}}) x BR(H {yields} b{bar b}) for Higgs masses between 105 and 135 GeV.
Date: January 1, 2006
Creator: Melnitchouk, Alex & U., /Mississippi

The D0 silicon micro-strip tracker

Description: The D0 silicon micro-strip tracker (SMT) is part of the D0 upgrade for the Tevatron RunII at Fermilab. The detector has been running successfully since the start of the RunII physics data taking. The tracking and vertexing performance match the expectation from Monte-Carlo studies. An additional inner layer (Layer0) of silicon sensors at R = 1.6cm will be installed in 2005.
Date: January 1, 2006
Creator: Weber, Michael S. & /Fermilab

D0 silicon microstrip tracker

Description: The D0 Run II silicon microstrip tracker (SMT) has 3 square meters of Si area. There are 792,576 channels read out by 6192 SVXIIe chips on 912 read out modules. The SMT provides track and vertex reconstruction capabilities over the full pseudorapidity coverage of the D0 detector. The full detector has been running successfully since April 2002. This presentation covers the experience in commissioning and operating, the recent electronics upgrade which improved stability of the SMT and estimates of the radiation damage.
Date: November 1, 2005
Creator: Burdin, Sergey

D0 Silicon Strip Detector Upgrade Project SVX Sequencer Controller Board

Description: The Sequencer Controller boards are 9U by 340mm circuit boards that will reside in slot 1 of each of eight Sequencer crates in the D0 detector platform. The primary purpose is to control the Sequencers during data acquisition based on trigger information from the D0 Trigger Framework. Functions and features are as follows: (1) Receives the Serial Command Link (SCL) from the D0 Trigger System and controls the operation of the Sequencers by forming a custom serial control link (NRZ/Clock) which is distributed individually to each Sequencer via the 11 Backplane; (2) Controllable delays adjust NRZ control link phasing to compensate for the various cable-length delays between the Sequencers and SVX chips, delay control is common for slots 2-11, and for slots 12-21 of the crate; (3) Each NRZ control link is phase controlled so that commands reach each Sequencer in a given half-crate simultaneously, i.e., the link is compensated for backplane propagation delays; (4) External communication via MIL-STD-1553; (5) Stand-alone operation via 1553 trigger commands in absence of an SCL link; (6) 1553-writeable register for triggering a laser, etc. followed by an acquisition cycle; (7) TTL front panel input to trigger an acquisition cycle, e.g. from a scintillator; (8) Synch Trig, Veto, Busy and Preamp Reset TTL outputs on front panel LEMOs; (9) On-board 53.104 MHz oscillator for stand-alone operation; (10) 1553 or SCL-triggerable Cal-inject cycle; (11) Front-panel inputs to accept NRZ/Clock link from the VRB Controller; (12) Front panel displays and LEDs show the board status at a glance; and (13) In-system programmable EPLDs are programmed via Altera's 'Byteblaster'.
Date: May 29, 2001
Creator: Utes, M. & /Fermilab

The D0 Silicon Tracker

Description: The D0 silicon micro-strip tracker, which was installed for Run II of the Fermilab Collider, and an inner silicon micro-strip layer 0, which was installed for Run IIb of the Collider, are described.
Date: August 1, 2008
Creator: Cooper, W.E. & /Fermilab

D0 silicon trackers

Description: The present Fermilab D0 silicon microstrip tracker, the silicon microstrip tracker which was designed to replace it, and plans for upgrading the present silicon tracker are described.
Date: December 19, 2003
Creator: Cooper, W. E.

D0 Silicon Upgrad: D0 Silicon Cooling System

Description: The cooling system design is not complete. This paper lays out the general design and some of the design calculations that have been performed up to this date. Further refinement will be performed. This is especially true in the piping layout, piping insulation and detector manifold areas. The silicon detector is cooled by means of a coolant in the beryllium channels that also act as the primary supporting device for the silicon ladders and wedges. The coolant is water with ethylene glycol added as a freezing point depressant. The glycol concentration in the coolant is 30% by weight resulting in a freezing point of approximately -15 C. If the water/glycol is not sufficient for maintaining the desired detector temperature the concentration of the water/glycol may be changed or an alternative coolant may be used.
Date: July 14, 1998
Creator: Squires, B. & /Fermilab

D0 Silicon Upgrade: 3 Chip Ladder Heat Transfer

Description: The Silicon Mechanical group has submitted a 3 chip ladder drawing to the Fermilab Analysis Group (Zhijing Tang) to determine the temperature distribution in the ladder during detector operation. Heat transfer by convection and radiation is assumed negligible and two dimensional PEA conduction solutions were performed. The heat flux at the SVX IT chip region is assumed to be 8.359 mW/mm{sup 2} which corresponds to roughly 0.48 W per SVX II chip. The heat flux in the region of the transceiver is assumed 8.801 mW/mm{sup 2}, corresponding to 1.6 W in this region. Total heat load of the 3 chip ladder is assumed to be 3.04 W. The 3 chip ladder submitted for analysis is shown in the figure below. The multichip module (MCM) is mounted on beryllium plate which serves to carry the heat load of the chips and the transceiver to the cooling channel. Adhesive thermal conductivity is 1.6 W/m-K, based on the published value of the selected adhesive. Actual measurements of thermally conductive adhesives indicate that the assumed 1.6 W/m-K is high. Experience gained in measuring adhesive thermal conductivity indicates 0.9-1.2 W/m-K as a more reasonable number to use. The effect of the uncertainty of the adhesive thermal conductivity on silicon temperature is discussed.
Date: September 19, 1994
Creator: Ratzmann, Paul & /Fermilab

D0 Silicon Upgrade: ASME Code and Pressure Calculations for Liquid Nitrogen Subcooler

Description: Included in this engineering note are three separate calculation divisions. The first calculations are the determination of the required thickness of the LN{sub 2} subcooler flat head according to ASME code. This section includes Appendix A-C. The minimum plate thickness determined was 0.563 in. The actual thickness chosen in fabrication was a 3/4-inch plate milled to 0.594-inch at the bolt circle. Along with the plate thickness, this section calculates the required reinforcement area at the top plate penetrations. It was found that a 1/4-inch fillet weld at each penetration was adequate. The next set of calculations were done to prove that the subcooler internal pressure will always be less than 15 psig and therefore will not be classified as a pressure vessel. The subcooler is always open to a vent pipe. Appendix D calculations show that the vent pipe has a capacity of 1042 lbs/hr if 15 psig is present at the subcooler. It goes on to show that the inlet piping would at that flow rate, see a pressure drop of 104 psig. The maximum supply pressure of the LN{sub 2} storage dewar is 50 psig. Appendix E addresses required flow rates for steady state, loss of vacuum, or fire conditions. Page E9 shows a summary which states the maximum pressure would be 1.50 psig at fire conditions and internal pressure.
Date: October 4, 1995
Creator: Kuwazaki, Andrew; Leicht, Todd & /Fermilab

D0 Silicon Upgrade: Cable Power Dissipation in the D0 Silicon Tracker

Description: Readout cables extend from the ladder end to the outer barrel radius in the region where the F-disks are mounted. In this region it is difficult to know what the gas temperature will be due to the power dissipating components on the F-disks and power from all the cables. This region is convectively cooled by the barrel bulkhead and the F-disk cooling channel. Power dissipated in the cable will not only warm the surrounding gas but will warm the hybrid to which it is attached on the ladders and disks. Just how much power goes into the hybrid will be estimated here. Physically, the cable is composed of two layers of copper which are separated and encased by 3 layers of kapton. The central kapton layer is 0.001-inch thick, the outer two kapton layers are 0.0005-inch thick, and the two copper layers are 0.0006-inch thick. Mike Matulik estimated the power dissipation of the cables for the 3. 6, and 9 chip ladders. These estimates are based on the assumed cross-sectional area of copper in the cable and the current these cables will carry, for a 12-inch cable length. The assumed powers are 14, 49, and 114 mW, respectively. The cable power dissipation is modeled using the finite difference technique. To determine the allowable node size for this simulation a 5-inch cable was simulated, with the same cross-sectional area and nominal power dissipation approximately equal to the power dissipated in the 6 chip ladder cable. Node sizes of 25, 50, and 100 mils are considered. Considering Figures 1 and 2,100 mil nodes will be used for future simulations, considered adequately small to simulate the cable.
Date: July 8, 1996
Creator: Ratzmann, Paul M. & /Fermilab

D0 Silicon Upgrade: Calc. to Determine Need for a N2 Phase Separator

Description: A nitrogen phase separator is recommended on the liquid supply line at the helium refrigerator plant. This engineering note documents the calculations done to reach that conclusion. The steady state liquid nitrogen consumption rate for the refrigerator, VLPC and solenoid systems is about 30 gal/hr. The estimated heat leak for the piping run to the refrigerator location is 50 watts. The calculated quality at the refrigerator was 0.032. Given this quality, a two phase flow model based on Lockhart-Martinelli and also incorporating Baker diagram nomenclature was run on TK solver. The result of this program was that without the use of a phase separator we could expect a slug flow pattern with a volume fraction of gas of 65%. Based on this, I recommend that we use a phase separator to siphon off the gas before the nitrogen is sent to a standard saver type subcooler. Including the phase separator will help ensure proper operation of the subcooler. The subcooler will help us attempt to deliver single phase liquid to the nitrogen control valves.
Date: April 7, 1995
Creator: Rucinski, Russ & /Fermilab

D0 Silicon Upgrade: Calculating Mass Flow Rates at Sub-Sonic Conditions Trhough Venturis (FT-4052-H & FT-4053-H) and an Orifice Plate (F)-2019-H)

Description: The purpose of this engineering note is to explain the method involved in calculating the mass flow rates through venturis and orifice plates at sub-sonic conditions. In particular, the mass flow rate calculations are required for two FLOW-DYNE venturi flow meters, serial no. 35821 and no. 35822, and an orifice plate flow meter, serial no. 35823. The two venturis, FT-4052-H and FT-4053-H, are located in the D-Zero VLPC valve box at the refrigerator and the orifice plate, FO-2019-H, is on the high pressure helium supply line in the assembly building.
Date: August 15, 1996
Creator: Zaczek, Mauiusz

D0 Silicon Upgrade: Calorimeter Installation Bridge Non-Destructive Test Result

Description: After the central calorimeter was installed on the center beam a cracked weld was found on the bridge. The weld was a partial penetration between the top rail plate and the T-1 steel nose section. The crack is fully across the width of the rail plate and the rail is depressed in a concave shape. That is, the depression is deeper in the center and feathers out to zero at the end of the rail. Upon close inspection it was obvious that there was no penetration of weld metal into the T-1 material. The assumption is that the T-1 was not properly pre-heated before welding. The reason for the concave depression comes from the fact that the rail plate rests on the flanges of the 'S' beams and that during welding the plate pulled off the beams. This weld failure can not propagate to any other welds and therefore, will not start a chain of failures. Clearly the failure of this weld did not hinder the installation of the central calorimeters. This weld failure occurred on both sides of the bridge. This failure did, however, alert us to check the critical weld on the bridge, S-beam webs to T-1 nose section, to assure us we had a sound weldment. (Note: it must be used again for both EC's). We contacted M.Q.S. Inspection Inc. (Lab contractor for N.D.T.). A technician from M.Q.S. came to DAB and performed an ultrasonic examination of the welds in question. The exam showed that we don't have a full penetration weld of the S Beam web, but that it is between 67-83%. A calculation was performed based on 67% penetration and the CC & EC loads. In both cases the weld stresses were well within acceptable limits (see calculations attached). Based on this result, it is ...
Date: October 29, 1990
Creator: Stredde, H. J.

D0 Silicon Upgrade: Commissioning Test Results for D-Zero's Helium Refrigerator

Description: The test objectives are: (1) Make liquid helium and measure refrigerator capacity; (2) Measure liquid helium dewar heat leak, transfer line heat leak, and liquid nitrogen consumption rates; (3) Operate all cryogenic transfer lines; (4) Get some running time on all components; (5) Debug mechanical components, instrumentation, DMACs user interface, tune loops, and otherwise shake out any problems; (6) Get some operating time in to get familiar with system behavior; (7) Revise and/or improve operating procedures to actual practice; and (8) Identify areas for future improvement. D-Zero's stand alone helium refrigerator (STAR) liquified helium at a rate of 114 L/hr. This is consistent with other STAR installations. Refrigeration capacity was not measured due to lack of a calibrated heat load. Measured heat leaks were within design values. The helium dewar loss was measured at 2 to 4 watts or 9% per day, the solenoid and VLPC helium transfer lines had a heat leak of about 20 watts each. The liquid nitrogen consumption rates of the mobile purifier, STAR, and LN2 subcooler were measured at 20 gph, 20 to 64 gph, and 3 gph respectively. All cryogenic transfer lines including the solenoid and visible light photon counter (VLPC) transfer lines were cooled to their cryogenic operating temperatures. This included independent cooling of nitrogen shields and liquid helium components. No major problems were observed. The system ran quite well. Many problems were identified and corrected as they came up. Areas for improvement were noted and will be implemented in the future. The instrumentation and control system operated commendably during the test. The commissioning test run was a worthwhile and successful venture.
Date: June 30, 1997
Creator: Rucinski, Russ

D0 Silicon Upgrade: Control Dewar Steady State Thermodynamic Operating Goals

Description: This engineering note documents the thermodynamic operating parameter goals for the steady state operation of the control dewar/solenoid system. Specifically, how the control dewar pressure control valve, PV-3062-H and the magnet flow control valve EVMF are operated to give the lowest possible temperature fluid at the solenoid magnet. The goals are: (1) For PV-3062-H - The process variable is the helium reservoir pressure, minimize the reservoir pressure, provide only enough pressure plus a little margin to ensure leads flow; and (2) For EVMF - The process variable is firstly a manual setpoint of flowrate as read by the flow venturi, FE3253-H, and secondly the reservoir liquid level, minimize the pressure drop thru the solenoid cooling tubes, provide at least enough flow to maintain reservoir level and stable operation of the magnet. The thermodynamic states for the fluid thru the system are shown on the Pressure versus Temperature graph. Lines of constant enthalpy are also shown. State A is shown as two phase liquid entering the inlet of the subcooler. The subcooler subcools the fluid to State B. State B to State C is caused by the pressure drop across EVMF. State C to D is the estimated pressure drop from the outlet of EVMF thru the solenoid cooling tubes and back up to the helium reservoir inlet. To give the coolest fluid in the cooling tubes, the two phase fluid in the reservoir should be at the lowest pressure (and thus temperature). This lowest pressure is limited by the required pressure for leads flow and if this does not dominate, the low pressure side pressure drop thru the refrigerator and suction pressure set point. My guess is the lead flow requirement will dominate. I suggest putting the PV-3062-H set point such that the lead flow control valves operate at about ...
Date: October 20, 1995
Creator: Rucincki, Russ

D0 Silicon Upgrade: Control Dewar Venturi Calibration Explanation for Toshiba

Description: This document is intended to explain the calibration data for the venturi, FE-3253H, which is installed in the control dewar. Further, this document will help explain how to use the venturi to make mass flow measurements during typical operating conditions. The purpose of the calibration data enclosed from the Colorado Engineering Experiment Station Inc. is to experimentally show that the venturi follows the flow equation which is enclosed as Eq. 7-36 on page 155, from the Applied Fluid Dynamics Handbook. The calibration data serves to show that the Subsonic Venturi, Serial Number 611980-18, produces results predicted by the compressible subsonic flow mass flow rate equation above and to experimentally determine the discharge coefficient C. Colorado Engineering Experiment Station Inc. ran tests at 15 independent differential pressures to conclude that use of this venturi will perform according to the mass flow rate equation. In order to verify the results from the Colorado Engineering Experiment Station Inc. we have provided you with a step-by-step procedure using the values they have chosen.
Date: January 24, 1997
Creator: Kuwazaki, Andrew

D0 Silicon Upgrade: Cryogenic and Safety Considerations for Moving the South End Cap Calorimeter to the Sidewalk

Description: The south end cap calorimeter (ECS) will need to be moved off of the detector platform to allow for the installation of new central tracking components. This engineering note documents the cryogenic and safety issues associated with the planned move. Because of the difficulty involved in building a temporary vent line out of the building, we plan to vent the ECS condenser flow, 6 scfm N2 into the assembly hall atmosphere. Information contained herein proves that this is safe even for failure/relief conditions. The details regarding the cryogenic and safety aspects of the ECS move have been thought out and planned. The cryogenic operation of the ECS calorimeter will be limited to maintaining it's pressure by keeping it cold and isolated while it is in it's temporary position off the platform. The 4 gph liquid nitrogen flow required for this operation is easily absorbed into the DZero assembly building atmosphere without any safety concerns. Emergency or failure scenarios have been addressed on a conservative basis and also pose little threat. Other safety features built into the system such as the liquid nitrogen excess flow switch, vent line liquid sensor, and monitored ODH heads provide additional assurance that an unexpected hazard would be identified and contained.
Date: September 25, 1996
Creator: Rucinski, Russ

D0 Silicon Upgrade: Cryogenic Line Routing: Refrigerator to VLPC Cryostats & Solenoid

Description: This engineering note documents the proposed cryogenic line routing from the liquid helium (LHe) refrigeration plant to the detector solenoid and VLPC cryostats. Many figures are included to aid in understanding the route. As an appendix, I include some general comments relevant to the topic. Also listed are a number of routing options that were considered before the proposed route was finalized.
Date: October 4, 1994
Creator: Rucinski, Russ

D0 Silicon Upgrade: Cryogenic Lines at Refrigerator : Thermal Contraction Analysis of Four Cryogenic Utility Lines for the D0 Upgrade

Description: The cryogenic lines GHE and LN2 contain two lines each, one for supply and the other for return. The tubing was stress analyzed per ASME code for pressure piping, standard ANSI/ASME B31.3. A commercial pipe stress analysis and design system by ALGOR{reg_sign} was used for the analysis along with the calculated maximum stress, 25,050 psi. They were all analyzed for combined pressure, thermal movement, and dead weight and all the stresses were below this allowable stress limit. There are sections of the transfer lines that will be increased from a 1-1/2-inch vacuum jacket to a 2-inch vacuum jacket. This increase accounts for the maximum displacement, 0.466-inch in troubled areas as seen in subsequent drawings. The greatest displacement allowed for a 1-1/2-inch vacuum jacket is 0.421-inch for a 1/2-inch pipe on the nominal centerline. The greatest displacement allowed for a 2-inch vacuum jacket is 0.658-inch. We will have a clearance of 0.192-inch when using the 2-inch vacuum jacket.
Date: June 23, 1995
Creator: Kuwazaki, Andrew