8 Matching Results

Search Results

Advanced search parameters have been applied.

D0 Silicon Upgrade: Redesign of the Low Conductivity Water (LCW) System at D-Zero

Description: Due to the relocation of a magnet power supply, the installation of a buss, and an installation of chokes. and their need for cooling water a redesign of the Low Conductivity Water (LCW) system has been undertaken. This new system required the determination of an optimal pipe diameter for the High Bay pipe as well as the determination of the pressure drop and temperature rise in the buss. Based on numerous calculations it has been determined that the High Bay pipe should be 1 1/2 inch (1.90 O.D. x 1.610 I.D-40S steel). While the pressure drop in the buss was calculated to be 7.699 psi. Based on such a low pressure drop, no need for any additional pumps has presented itself. Finally, the temperature rise in the buss has been determined to be about 29.39 F for the Assembly Hall (route No.1). and 13.93 F for the Collision Hall (route No.2). The purpose of this engineering note is to explain the redesign of the low conductivity water system (LCW) at D-Zero. The areas to be covered include the sizing of the High Bay, the pressure drop and temperature rise in the buss. In addition, I will try to determine if any more pumps are needed to support this new system. Originally, the purpose of the LCW was to provide cooling for the EF, CF, SAMUS magnets and the magnet power supply. The water source is composed of two 1 1/2 BC, 20 hp, centrifugal pumps (see Table No.2) which are located in room 604 of the D-Zero Assembly building.
Date: October 15, 1996
Creator: Zaczek, Mariusz
Partner: UNT Libraries Government Documents Department

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.
Partner: UNT Libraries Government Documents Department

Exhaust Fan Temperature Switch

Description: The 13000 cfm 'emergency' vent fan must be protected from over cooling which would result in a mechanical failure. Over cooling could result from a catastrophic cryogen release from the cryostat(s) or Argon Storage Dewar. In order to protect the fan, a VPT has been calibrated for -31 C to open a switch which sends a signal to allow warm gas to enter the sump by means of a motor controlled louver installed at 'sidewalk level' in the ductwork between the assembly hall and the Argon Dewar Enclosure. The bulb of the VPT is enclosed in a thermal well and will be placed in the gas stream directly above the fan. The switching unit will be mounted nearby on the wall in order to isolate it from vibrational effects. Should the fan be activated due to a cryogen release, it should not experience any problems when operating above -40 C. The switch was set and checked in a saturated calcium chloride solution cooled to -31 C by running cold gaseous Nitrogen through a copper tube coiled in a dewar. Switching temperature was measured by a thermocouple tied to the VPT bulb. The thermocouple was checked in LN2, in an ice water bath, and against an ordinary thermometer (which was assumed to be accurate to plus or minus 0.3 C) at room temperature. The results are shown below in 'Table 1' By interpolation of the data, thermocouple error at -31.0 C was found to be 0.43 C on the warm side. Since this error was small, it was ignored. 'Table 2' shows the results of the tests. Ten readings were taken with the switch wired in the 'normally open' mode. This results in a signal at room temperature. The worst deviation was 2.5 C. Three readings were then taken from the ...
Date: May 11, 1989
Creator: Ball, G. S.
Partner: UNT Libraries Government Documents Department

Spectrum and Charge Ratio of Vertical Cosmic Ray Muons up to Momenta of 2.5 TeV/c

Description: The ALEPH detector at LEP has been used to measure the momentum spectrum and charge ratio of vertical cosmic ray muons underground. The sea-level cosmic ray muon spectrum for momenta up to 2.5 TeV/c has been obtained by correcting for the overburden of 320 meter water equivalent (mwe). The results are compared with Monte Carlo models for air shower development in the atmosphere. From the analysis of the spectrum the total flux and the spectral index of the cosmic ray primaries is inferred. The charge ratio suggests a dominantly light composition of cosmic ray primaries with energies up to 10{sup 15} eV.
Date: September 14, 2012
Creator: Schmelling, M.; Hashim, N. O.; Grupen, C.; Luitz, S.; Maciuc, F.; Mailov, A. et al.
Partner: UNT Libraries Government Documents Department

SLD Trip Report

Description: The author visited the facility to gain an insight in the experience of the LAr filling of the SLD Barrel and North End Cap, and the cooldown of the South End Cap. Cryogenic commissioning began mid-September, 1989, and continued to Cooldown, January 3, 1990. Cryogenic commissioning followed the construction and installation of the piping. The checkout was serial and problems found 'as we were going along'. There was a clear message to work in parallel and certify subsystems in advance of their need. Typical problems were VJ line external bellows and ball valves that were not He leak tight. The early preparations concentrated on the relief (singular) of the LAr 100,000 I dewar (sound familiar?). About one month was lost to the refurbishing of valves. After commissioning the dewar they accepted four LAr transfers for a total of 15,000 gallons, each in the range of 0.4-0.6 ppm O{sub 2} measurement with equipment accurate to +/- 0.1 ppm. As I watched, tests were concluding that qualified the Barrel calorimeter as having LAr with 0.6 +/- 0.1 ppm O{sub 2} to the delight of those making the measurement. There was real satisfaction in the recent HV measurement that only 55 of 40,000 channels had shorts. The ratio is essentially that predicted from the early module testing experience and another reason to celebrate. Twelve of the twenty-four Barrel feedthroughs flanges (one end, total is forty-eight) had been fitted with Pre-Amps and that installation seemed to be going very well. There are hermetic feedthroughs at the PV wall, a length of manganin wire in the vacuum space to a warm hermetic feedthrough flange that is double 'O' ring sealed in the vacuum vessel closure plate. The Pre-Amps mount directly to the atmospheric side of these feedthrough flanges. The instrumentation is 'Bare Bones'. There was ...
Date: April 13, 1990
Creator: Mulholland, G.T.
Partner: UNT Libraries Government Documents Department

Pipe Cleaning Operating Procedures

Description: This cleaning procedure outlines the steps involved in cleaning the high purity argon lines associated with the DO calorimeters. The procedure is broken down into 7 cycles: system setup, initial flush, wash, first rinse, second rinse, final rinse and drying. The system setup involves preparing the pump cart, line to be cleaned, distilled water, and interconnecting hoses and fittings. The initial flush is an off-line flush of the pump cart and its plumbing in order to preclude contaminating the line. The wash cycle circulates the detergent solution (Micro) at 180 degrees Fahrenheit through the line to be cleaned. The first rinse is then intended to rid the line of the majority of detergent and only needs to run for 30 minutes and at ambient temperature. The second rinse (if necessary) should eliminate the remaining soap residue. The final rinse is then intended to be a check that there is no remaining soap or other foreign particles in the line, particularly metal 'chips.' The final rinse should be run at 180 degrees Fahrenheit for at least 90 minutes. The filters should be changed after each cycle, paying particular attention to the wash cycle and the final rinse cycle return filters. These filters, which should be bagged and labeled, prove that the pipeline is clean. Only distilled water should be used for all cycles, especially rinsing. The level in the tank need not be excessive, merely enough to cover the heater float switch. The final rinse, however, may require a full 50 gallons. Note that most of the details of the procedure are included in the initial flush description. This section should be referred to if problems arise in the wash or rinse cycles.
Date: January 24, 1991
Creator: Clark, D. & Wu, J.
Partner: UNT Libraries Government Documents Department

D0 Collider Detector LINDE, East Chicago (LAr Contractor) Trip Report

Description: East Chicago is capable of processing air at a 6-7E6 SCFH rate. They can produce as much as 1.2E6 SCFH 02 and 4.5 SCFH N2 (not coincidently) with a peak product efficiency of 85-86% (product to total Intake). The general area demand has been as high as 10E6, as low as 4.5E6, and is currently 8E6 SCFH totaI product. The plant is really four plants in one. At anyone time one or more plants can be down for maintenance and the others online and delivering to the pipe line that distributes their product to nearby steel plants, and to the liquid reservoirs (perlite insulated tanks) of 160, 160 and 200 E6 SCF. At the time of our visit two plants were down and two were on line. The following describes the characteristics of one of the four plants. The cycle requires a base compressor (Brown Boveri, 22,600 hp) that pumps to 90-100 psig, and a booster compressor (Clark, 14,000 hp) that pumps to 300 psig. Filter houses (ca. 20-ft x 20-ft) feed the suctions and the discharge is scrubbed by dual, molecular sieve, beds 0 300 psi (6-8 hour cycle time). The beds are provided with dust blow down and down stream filter provisions. The scrubbers remove CO2, the heavy HC, and water. The effectiveness of the scrubbers is measured by the record 6 years one of the plants ran w/o the need for thawing. The thaw operation takes about 4 days. It was interesting to learn that a plant can be brought on line in two and one half hours from a warm start. Major swings from N2 rich to O2 rich production take about an hour. Argon is a small constituent in air (0.61) and thus not a major product. It comes off the main column at 761 ...
Date: February 8, 1991
Creator: Dixon, K.; Krempetz, K.; Mulholland, G.T.; Urbin, J. & /Fermilab
Partner: UNT Libraries Government Documents Department

Preliminary results from the MINERvA experiment

Description: The MINERvA experiment, operating since 2009 in the NuMI neutrino beam line at Fermilab, has collected neutrino and antineutrino scattering data on a variety of nuclear targets. The detector is designed to identify events originating in plastic scintillator, lead, carbon, iron, water, and liquid helium. The goal of the experiment is to measure inclusive and exclusive cross sections for neutrino and antineutrino with much greater precision than previous experiments. We present preliminary kinematic distributions for charged current quasi-elastic scattering and other processes.
Date: November 1, 2011
Creator: Harris, Deborah A.
Partner: UNT Libraries Government Documents Department