(Fermilab), Jamieson OLSEN
(Fermi National Accelerator Laboratory)
Summer Internships in Science and Technology
Gas Transport in the Mu2e Detector Straws
The Mu2e transverse tracker will utilize over 20,000 Mylar straws of varying lengths connected in parallel to gas manifolds. Impurities in the Ar/CO2 supply could cause unwanted chemical reactions within the straw to take place, potentially damaging the sense wire and locally reducing the gain of the straw. By ensuring that a constant fresh supply of gas traverses the straw, these reactions can be impeded. If the system were dominated by flow, the resistance experienced by the gas would be proportional to the length of the straw, which may cause the flow in longer straws to be severely inhibited. Much of the summer was spent determining whether flow or diffusion was the dominant method for gas transportation through the straw, and whether the system could operate effectively in parallel.
Search for Standard Model Higgs Boson in the WH->WWW->lv.jj.jj Channel
During the summer of 2011, work began on the intermediary stages of an analysis of the high-mass Standard Model Higgs boson in associated production with a W boson. This channel, WH->WWW->lv.jj.jj, is of particular interest since it has not yet been investigated by any other analysis group. Continued efforts are being focused on finalizing the results of the data and Monte Carlo simulations for this analysis.
(Summer Internships in Science and Technology)
Calorimetry for future Lepton Colliders
New projects for lepton colliders are developing around the world. The necessity for building capable detectors for these acceleratos is important. This project studies the advantages and limitations of a dual readout calorimeter when obtaining data from a linear accelerator.
Developing high-current, mechanically reinforced BSCCO 2212 cable: a survey of compatible materials
BSCCO 2212, a high temperature superconductor currently under extensive experimentation at Fermilab has the potential to be used in next generation accelerator magnets which would operate in the field range of 20 - 50T. However BSCCO 2212’s strain sensitivity is a considerable problem when operating in these high magnetic fields. In order to solve this problem alloy wire reinforcement to be used in high current multi-strand cables is being considered. These alloy wires have to fulfill two requirements, they must be mechanically strong, and they must be chemically compatible with 2212 wire. I performed tensile testing, and chemical compatibility testing on 5 different alloys, Inconel 600/625/X750, nickel chromium, and Kanthal A-1. Testing has indicated that Inconel X750 and Kanthal A-1 are possible candidates for 2212 reinforcement. Testing has also shown that titanium oxide and aluminum oxide coatings may be effective in reducing chemical interaction between 2212 wire and alloy wire.
FPGA beam loss monitor system for the SRF facility
A Field Programmable Gate Array (FPGA)-based Time-to-Digital Converter (TDC) is being developed for use with cryogenic ionization chamber beam loss monitors which have been proposed for installation inside the cryostats at the Superconducting Radio-Frequency (SRF) beam test facility at Fermilab. The scheme employs an Altera Cyclone III FPGA and He-ionization chambers with recycling integrators as dose rate monitors. The time intervals between the pulses out from the dose rate monitors are measured with high timing resolution (> 10 bits) using this TDC method. This provides a more accurate measure of the current than was previously possible. The FPGA was initially programmed with a single channel output for test purposes; however several additional channels are required for the final phase. This project has extended the new design to handle multiple channel output up to 8 channels with a timing resolution of 1 ns(nano-second). This project discusses the design and test results that we have obtained so far.
Three new RF cavities are required to perform multi-batch slip stacking in the Recycler Ring to increase the proton intensity of the NuMI beamline for the NOvA project to study muon to electron neutrino oscillations. Two RF cavities will operate at a 1200 Hz difference in frequency, and one will be used as a spare. The cavities are made from high conductivity copper (OFHC) and operate in the quarter-wavelength transverse electromagnetic mode with a length slightly reduced by the gap capacitance at the accelerating voltage end. In this study, we present results from low power measurements of one of these cavities. We used coaxial cables hooked-up to a Network Analyzer to transmit power into its structure and measure the resonant modes. After adjusting the length of the cavity, the fundamental mode which is used to accelerate the beam during slip stacking, was measured very close to the desired operational value of 52.809 MHz. The higher order modes of the cavity were also identified, and prototype dampers were constructed to test their ability to suppress them. To determine the frequency tuning range of the cavity, tuners were also developed. These RF devices were able to optimize the cavity’s performance.
(Stony Brook University)
Search for the Higgs Boson in the WH->lvbb and WH->WWW->lv.jj.jj Channels
Throughout the summer of 2011, work continued on the analysis of the associated production of the Higgs boson. Our particular analysis was the WH → lνbb decay channel. This channel has the highest branching ratio of the low-mass Higgs decay channels and thus is one of the most sensitive channels to analyze, resulting in a solid framework and a good foundation. Work was also done on the WH → WWW → lνjjjj decay channel. This channel is unique within DØ because there are only a few people working on it, all whom are summer students. This paper explains ongoing efforts to process data and Monte Carlo (MC) samples, model data correctly, and utilize the output of multivariate training to effectively distinguish between signal and background events and perform a search for the Higgs Boson. It also discusses new variables that were added to the search and how they impacted the overall analysis.
(Michigan State University)
Simulation of Quench in an 11 T Dipole Magnet
On 19 September 2008, approximately 100 of CERN’s dipole magnets quenched due to faulty electrical systems. This problem resulted in rapid heating of the magnets and the loss of 6 tons of liquid helium as well as the destruction of 53 dipole magnets, which had to be replaced at a cost of $21,000,000. This in turn delayed the LHC from accelerating particles to “high energy” until November 2009, more than a year later. To avoid such a catastrophe ever happening again, it was decided that each magnet would be fitted with a heater and a dump resistor to facilitate the quick and safe shutdown of the magnet. To that end, I was commissioned to update a simplified 3D model of the dipole magnets with new geometry and retool the analysis performed on the old model in 2003 to work with the geometry of CERN’s dipole magnets. The analysis was performed using ANSYS 7.0 in 2003 and 13.0 in 2011. Unfortunately, I was unable to perform the analysis in full as the 3D analysis takes 10 days to run on the computer that was available to me at the time of project completion. I was, however, able to successfully run a 2D simulation, the results of which lie below.
(University of Illinois at Urbana-Champaign)
Meet in the Atrium
Note there is no lecture today.
Design and Implementation of a Motion Control Program to Assess the Consistency of the Flying Wire’s Feedthrough and Coupling
The reliability of the hi-flex bellow coupling and the magnetic feedthrough utilized in the Flying Wire systems are two prime components that require research to increase dependability. The current design of the Flying Wire system has an issue with the coupling and the feedthrough being overwhelmed from prolonged use. In order to improve the dependability of these two components, a motion control system was designed to test these specific components. Using a test setup, a motion control program was written to analyze the consistency of the coupling and feedthrough. The motion control program was created by programming the Elmo Solo Whistle digital servo drive, which stores and executes the designed program. The system had to be tuned so that the Elmo Solo Whistle digital servo drive can provide the most suitable parameters while also reducing error. Once the setup has been tuned, the system operated continually for about 5 days to gather data about the coupling and feedthrough. This paper reviews the hardware and software format, proficiencies, and the results from the test system.
Bead-Pull is a most commonly used Radio Frequency (RF) field measurement technique. RF field measurements play an important role in qualifying any RF cavity. They are used in evaluating the field distribution inside a resonant structure and in tuning them to obtain the required field flatness. The Bead-Pull system consists of a small dielectric or metallic bead being pulled through a cavity while the electric field measurement in the cavities is done. A step motor and a pulley system guide the motion of the bead through the cavity while a Network Analyzer is used to take the RF measurements. A program is developed in National Instruments' Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW) to control the hardware of the Bead-Pull system. The software will coordinate the step motor's movement, acquire data via the Network Analyzer and process the data as required.
(University of Massachusetts, Amherst)
Web Application for the Dual Readout Calorimeter Database
(University of Rochester)
Laser Development for the New Muon Lab
This research conducted regards the development of upgrades on two projects that will be used in the New Muon Lab. The projects include the characterization of the Picosecond Pulsed Fiber Laser as the seed laser for the RF gun, and the development of the Diode Pumped chassis as the upgraded laser pump source for the two-pass and multi-pass amplifiers. The results of tests, the issues that arose, and the solutions to these issues will be covered for future use or consideration in NML.