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A high speed digitizing photomultiplier tube base for the KTeV CsI calorimeter

Description: A circuit has been designed to digitize PMT signals over an 18-bit dynamic range with 8-bits of resolution. The crucial element of the circuit is the custom charge integrating and encoding (QIE) ASIC. This chip is designed to operate at rates up to 53 MHz, and, in conjunction with an 8-bit FADC, generates 12-bit floating point output. Bench tests of a 17-bit version of the digital base demonstrated excellent noise performance, linearity and pedestal and gain stability. Twenty-five channels of digitizing PMT bases have been built and used for readout of a CsI array in a test beam at CERN. Performance of these devices in a beam environment is discussed.
Date: November 1, 1994
Creator: Whitmore, J.
Partner: UNT Libraries Government Documents Department

The performance of a high speed pipelined photomultiplier readout system in the Fermilab KTeV experiment

Description: The KTeV fixed target experiment at Fermilab is using an innovative scheme for reading out its 3100 channel CsI electromagnetic calorimeter. This pipelined readout system digitizes photomultiplier tube (PMT) signals over a 16-bit dynamic range with 8-bits of resolution at 53 MHz. The crucial element of the system is a custom Bi-CMOS integrated circuit which, in conjunction with an 8-bit Flash ADC, integrates and digitizes the PMT signal charge over each 18.9 nsec clock cycle (53 MHz) in a deadtimeless fashion.The digitizer circuit is local to the PMT base, and has an in-situ charge integration noise figure of 3 fC/sample. In this article, the readout system will be described and its performance including noise, cross-talk, linearity, stability, and reliability will be discussed.
Date: August 1, 1997
Creator: Whitmore, J.
Partner: UNT Libraries Government Documents Department

Physics prospects of the KTeV experiment at Fermilab

Description: KTeV is a new Fermilab fixed target experiment which will search for direct CP violation in the neutral kaon system. In addition, we will make precision measurements of other CP and CPT violating parameters and make high sensitivity studies of rare kaon decays. The detector has been commissioned and is currently taking data. The physics goals and detector performance are presented. 12 refs., 1 fig.
Date: October 1, 1996
Creator: Whitmore, J. & Collaboration, KTeV
Partner: UNT Libraries Government Documents Department

System Advisor Model: Flat Plate Photovoltaic Performance Modeling Validation Report

Description: The System Advisor Model (SAM) is a free software tool that performs detailed analysis of both system performance and system financing for a variety of renewable energy technologies. This report provides detailed validation of the SAM flat plate photovoltaic performance model by comparing SAM-modeled PV system generation data to actual measured production data for nine PV systems ranging from 75 kW to greater than 25 MW in size. The results show strong agreement between SAM predictions and field data, with annualized prediction error below 3% for all fixed tilt cases and below 8% for all one axis tracked cases. The analysis concludes that snow cover and system outages are the primary sources of disagreement, and other deviations resulting from seasonal biases in the irradiation models and one axis tracking issues are discussed in detail.
Date: December 1, 2013
Creator: Freeman, J.; Whitmore, J.; Kaffine, L.; Blair, N. & Dobos, A. P.
Partner: UNT Libraries Government Documents Department

Search for narrow structure in proton-antiproton annihilation cross sections from 1900 to 1960 MeV

Description: The anti pp annihilation cross section has been measured with good resolution (approx.2 MeV rms) in the mass range 1900-1960 MeV. No narrow structures are seen, the 90% confidence level upper limit being 8-12 mb-MeV for the integrated area of a resonance in this mass range. However, we do not rule out a very narrow bump-dip structure seen in an earlier experiment in the 1935-1941 MeV mass interval. The data also do not support the existence of a broad structure previously reported at 1937 MeV.
Date: January 1, 1985
Creator: Lowenstein, D.I.; Pealsee, D.C.; Miller, R.J.; Lewis, R.A.; Oh, B.Y.; Smith, G.A. et al.
Partner: UNT Libraries Government Documents Department

Results of hybrid photodiode irradiation by 200 MeV protons

Description: Hybrid Photodiodes (HPD, [1]) will be used as the photodetector for the Compact Muon Solenoid (CMS) Hadron Calorimeter (HCAL) readout [2]. The HPDs are required to operate in a high radiation environment, where the HCAL detector will receive a total ionizing dose of about 330 rads and a fluence of 4 x 10{sup 11} n/cm{sup 2} over a 10 year running period [3]. Effects of HPD irradiation by low energy neutrons were studied and reported previously [1]. In these studies, high energy protons are used to study possible effects of single event burnout [4], since high energy protons are more likely to induce large energy transfer within the HPD silicon. The HPDs were irradiated by 200 MeV protons at the Indiana University Cyclotron Facility [IUCF, 5]. The results of the study are presented.
Date: December 3, 2001
Creator: Baumbaugh, A.; Freeman, J.; Elias, J.; Los, S.; Mokhov, N.; Rivetta, C. et al.
Partner: UNT Libraries Government Documents Department

High resolution magnetic spectrometer for antiproton physics at rest and low energies

Description: A spectrometer is being installed in a high-intensity antiproton beam (LESBII) at the AGS. The beam momentum entering the target will be known to approximately +- /sup 1///sub 2/%. The target is surrounded by a stereoscopic cylindrical drift chamber, and thus the total charge of the event will be measured. Since the vertex will be reconstructed with an accuracy of approximately +- 2 mm, studies of annihilations with high resolution down to approximately 150 MeV/c will be possible. On one side of the target a large-aperture (2.3 x .62 m/sup 2/) magnet covered on both sides with drift chambers and triggering--TOF scintillation counters, will measure particle and ..gamma..-ray energies with high resolution, as well as identify particles. The primary objective is to look for peaks in the ..gamma.. spectra coming from annihilations at rest by converting them in a thin (.05 x/sub 0/) radiator before the magnet. Narrow peaks (< 1 MeV) which are produced with frequencies of approximately 10/sup -3/ or better are expected to be seen as 5 sigma effects. The principle and details of the spectrometer are presented.
Date: January 1, 1978
Creator: Lowenstein, D I; Peaslee, D C; Lewis, R A; Miller, R; Oh, B.Y. Pratap, M.; Smith, G A et al.
Partner: UNT Libraries Government Documents Department

A high speed, wide dynamic range digitizer circuit for photomultiplier tubes

Description: High energy physics experiments running at high interaction rates frequently require long record lengths for determining a level 1 trigger. The easiest way to provide a long event record is by digital means. In applications requiring wide dynamic range, however, digitization of an analog signal to obtain the digital record has been impossible due to lack of high speed, wide range FADCs. One such application is the readout of thousands of photomultiplier tubes in fixed target and colliding beam experiment calorimeters. A circuit has been designed for digitizing PMT signals over a wide dynamic range (17--18 bits) with 8 bits of resolution at rates up to 53 MHz. Output from the circuit is in a floating point format with a 4 bit exponent and an 8 bit mantissa. The heart of the circuit is a full custom integrated circuit called the QIE (Charge Integrator and Encoder). The design of the QIE and associated circuitry reported here permits operation over a 17 bit dynamic range. Tests of the circuit with a PMT input and a pulsed laser have provided respectable results with little off line correction. Performance of the circuit for demanding applications can be significantly enhanced with additional off line correction. Circuit design, packaging issues, and test results of a multirange device are presented for the first time.
Date: June 1, 1994
Creator: Yarema, R. J.; Foster, G. W.; Knickerbocker, K.; Sarraj, M.; Tschirhart, R.; Whitmore, J. et al.
Partner: UNT Libraries Government Documents Department