Kurtis F Johnson

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,873 new measurements from 758 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 118 reviews are many that are new or heavily revised, including a new review on Neutrinos in Cosmology.Starting with this edition, the Review is divided into two volumes. Volume 1 includes the Summary Tables and all review articles. Volume 2 consists of the Particle Listings. Review articles that were previously part of the Listings are now included in volume 1.The complete Review (both volumes) is published online on the website of the Particle Data Group (http://pdg.lbl.gov) and in a journal. Volume 1 is available in print as the PDG Book. A Particle Physics Booklet with the Summary Tables and essential tables, figures, and equations from selected review articles is also available.The 2018 edition of the Review of Particle Physics should be cited as: M. Tanabashi et al. (Particle Data Group), Phys. Rev. D 98, 030001 (2018).

Present experiments determine the most general (local, derivative-free, lepton-number conserving) leptonic four-fermion interaction hamiltonian of the normal and inverse muon decay. Numerical results are given for all ten complex coupling constants and nine T-violating amplitudes with respect to the "helicity projection form".

We report on the test beam results and calibration methods using high energy electrons, pions and muons with the CMS forward calorimeter (HF). The HF calorimeter covers a large pseudorapidity region ( $3\leq|\eta|\leq5$ ), and is essential for a large number of physics channels with missing transverse energy. It is also expected to play a prominent role in the measurement of forward tagging jets in weak boson fusion channels in Higgs production. The HF calorimeter is based on steel absorber with embedded fused-silica-core optical fibers where Cherenkov radiation forms the basis of signal generation. Thus, the detector is essentially sensitive only to the electromagnetic shower core and is highly non-compensating (e/h≈5). This feature is also manifest in narrow and relatively short showers compared to similar calorimeters based on ionization. The choice of fused-silica optical fibers as active material is dictated by its exceptional radiation hardness. The electromagnetic energy resolution is dominated by photoelectron statistics and can be expressed in the customary form as $\frac{a}{\sqrt{E}}\oplus{b}$ . The stochastic term a is 198% and the constant term b is 9%. The hadronic energy resolution is largely determined by the fluctuations in the neutral pion production in showers, and when it is expressed as in the electromagnetic case, a = 280% and b = 11%.

The components of the transverse polarization of the positrons in the decay μ+→e+νν have been measured as a function of the positron total energy. Their energy average is〈PT1〉=0.016±0.023, 〈PT2〉=0.007±0.023 (statistical plus systematic errors). The energy dependence of PT1 and PT2 yields the μ decay parameters αA, βA (with their linear combination η=(α−2β)A) and α′A, β′A, respectively. In an analysis based only on the most general, local, derivative-free four-fermion point interaction, and including all corresponding measurements, the complete set of parameters describing muon decay is determined for the first time.

The fundamentals of a new electromagnetic and hadronic sampling calorimetry based on the detection of Cherenkov light generated in quartz optical fibers are presented. Optical fibers transport light only in a selected angular range which results in a non-obvious and absolutely unique characteristic for this new technique: showers of very narrow visible energy. In addition, the technique is characterized by radiation resistance measured in Gigarads and nanosecond signal duration. Combined, these properties make quartz fiber calorimetry a very promising technique for high intensity heavy ion experiments and for the high pseudorapidity regions of high intensity collider experiments. The results of beam tests and simulations are used to illustrate the basic properties and peculiar characteristics of this recent development.

The positron directional distribution following muon decay is measured. The polarized muons are derived from pion decay in flight and are brought to rest in Be metal. Using the μSR-technique Pμξ = 1.0027 ±0.0084 is deduced. The integral asymmetry parameters ξ bears on the mass of the W̃ (wino, the supersymmetrical partner of the gauge boson W), mediating such decay as μ→eṽṽ. Assuming very light scalar neutrini mṽ⪡mμ a new lower limit on the wino mass mw̃>270GeV/c2 (90% CL) is inferred.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and Characterization of Wavelength-Shifting Monomers and Polymers Based on 3-HydroxyflavoneJayesh R. Dharia, Kurtis F. Johnson, and Joseph B. SchlenoffCite this: Macromolecules 1994, 27, 18, 5167–5172Publication Date (Print):August 1, 1994Publication History Published online1 May 2002Published inissue 1 August 1994https://doi.org/10.1021/ma00096a046RIGHTS & PERMISSIONSArticle Views292Altmetric-Citations32LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (735 KB) Get e-Alerts Get e-Alerts

Many samples of different plastic scintillators and scintillating fibers were irradiated with the Florida State University 2.5 MeV electron beam. The advantages of irradiating with an electron beam as compared to the standard gamma source were demonstrated: wide dynamic range of dose rates, possibility of irradiating long (and/or wide) samples, such as scintillating fibers, or simultaneous irradiation of many small samples in a short time. Study of effects of variation in sample composition and storage temperature during the recovery stage on the final level of radiation damage was performed. Finally, several samples of scintillating fibers were tested for radiation resistance. The 3-hydroxyflavone-doped fibers were found to recover best and show only small permanent damage after a 10 Mrad radiation dose.

A new measurement of the longitudinal polarization PL of the e+ from μ+ decay is presented here. Combined with our previously published result, we obtain PL = 0.998 ± 0.045 (statistical plus systematic error). We also report on the first measurement of PL(θ) where θ is the angle between the e+ line of flight and the μ+ polarization. The implications on the "low energy spectrum shape parameter η″, on the ratio of A coupling to V coupling and on time-reversal are discussed. The results are in agreement with the standard V-A form of the charged leptonic weak interaction.

The transverse polarization of the e+ in μ+ decay has been measured for the first time. This measurement allows the initial determination of the four μ decay parameters: αA and βA [with their linear combination η = (α − 2β)A] plus, as the first direct measurement of time reversal noninvariant parameters in a purely leptonic interaction, α′A and β′A. The results are consistent with zero and in agreement with the standard V - A form of the charged leptonic weak interaction.

An epoxide intermediate in the Algar–Flynn–Oyamada (AFO) synthesis of flavones is reaffirmed through the use of quinolone analogues to 3-hydroxyflavone (3HF). Stepwise synthesis of analogues 3-hydroxy-2-phenyl-1,4-dihydro-4-quinolone 11 and 3-hydroxy-1-methyl-2-phenyl-1,4-dihydro-4-quinolone 12, via chalcone formation, epoxidation, ring closing and final oxidation, has been accomplished. The intermediary of an epoxide is further supported by blocking cyclization with methoxy substitution at the 2′-position (1A). Absorption/emission spectroscopy of 11 and 12 shows large red shifts, as seen in 3HF, indicative of an excited state intramolecular proton transfer mechanism. Nitrogen analogues demonstrate photooxidative stability similar to that of 3HF.

Abstract Calorimeters based on silicon core fibres embedded into an absorber have been simulated by combining the GEANT 3.16 package and a proprietary routine describing Cherenkov photon production in optical fibres. The good agreement between simulation results and experimental data allows to study, with a high degree of confidence, the design of a prototype hadronic detector and of different calorimeter configurations to cover the very forward regions of an LHC experiment.

It is observed that thermal treatment of plastic scintillator can sensitize it to radiation damage.

The longitudinal polarization of the ${e}^{+}$ from ${\ensuremath{\mu}}^{+}$ decay has been measured. The spin dependence of positron-electron (Bhabha) scattering and of annihilation in flight were used as the analyzing reactions. The combined statistical and systematic error was reduced by a factor of approximately 3 below that of any previous measurement. The longitudinal polarization was found to be 1.010\ifmmode\pm\else\textpm\fi{}0.064 (statistical plus systematic error) and to be consistent with the prediction of the $V\ensuremath{-}A$ interaction.

Results on the light output of different kinds of silica fibres and on energy resolution and electromagnetic shower dimensions in small lead/quartz fibres calorimeter prototypes are presented, together with a possible design of a very forward calorimeter for LHC.

Samples of commercial, polymer-based scintillators (SCSN23, SCSN81, SCSN81+Y7, SCSN81+Y8 and 3HF) have been exposed in air to a radiation dose of 1.3 Mrad and at a dose rate of 267 rad/h from a 60Co source. The light yield and attenuation length were measured before and after irradiation. Results on the relative change in the light yield and the attenuation length versus dose are reported and they are compared with previous measurements at higher dose rates.

The authors present an update on research started three years ago with the goal of developing plastic scintillators able to endure annual doses of 10/sup 4/ to 10/sup 5/ Gy or more. Attention is given to radiation damage to plastic scintillators, techniques to improve radiation resistance (wavelength shifting and radiation-tolerant plastic bases), and other issues. It is concluded that, although the studies of scintillators must continue in order to define the limits of current capabilities, there is a need to move beyond the study of 'naked' scintillators (whether as plates or optical fibres) and to study them 'dressed' within a detector system.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A small quartz fiber calorimeter prototype with copper absorber has been assembled and tested at ITEP as a first test of a “0 degree” component of the RD-40 R&D program. Calibration and monitoring of each tower response was performed using the positions of single photoelectron peaks as well as the response to minimum ionizing particles incident at an angle of 45°. The response of the prototype to 4 GeV electrons as a function of beam angle with respect to the quartz fibers was studied in the range from 0° to 90°. The test results are compared to the GEANT based Monte Carlo (MC) simulations.

A series of high dose rate (20 kGy/hr) and low dose rate (<10 Gy/hr) irradiation of a large sample of plastic scintillating fibers (1 mm φ, 150 cm length) has been completed. Measurements of the transmission characteristics of the fibers have been completed and the results are presented in this report. The transmission measurements show striking features: (1) those fibers irradiated slowly in air (i.e., in the presence of oxygen) suffer the greatest level of damage, while (2) the fibers irradiated rapidly, and then allowed to recover, display the least amount of damage, and (3) fibers irradiated slowly in argon display a level of damage intermediate between the other two. One fiber, the green-emitting SCSF-Y8, is the only exception, and shows no difference in the level of damage observed in the three modes of irradiation.

The SDC collaboration for one of the SSC experiments has decided to use the tile-fiber system as the active medium of the calorimeter. Using commercially available scintillating plates and wave shifting fibers, the light output and radiation damage have been measured. The uniformity is within 5%, except near the edges for tiles of sizes 10 cm × 10 cm and 25 cm × 25 cm. The tested tile-fiber systems with radiation damage of up to 10 megarads retain their uniformity. The loss of light is about 15% for one megarad. Most scintillators and fibers are similar to each other, with variation in radiation damage of 10% to 20%. Light output increases approximately linearly with the diameter of the fiber. Radiation damage is less for tiles with multiple fibers.

Abstract Polystyrene (PS) and polyvinyltoluene (PVT) are in common use as base materials for plastic scintillators. Uv-vis spectroscopy was performed on irradiated disks of PS and PVT and the damage and recovery of these disks were monitored over time. By mounting the disks between quartz glass slides air diffusion was limited to two dimensions, and when the slides were mounted on a micrometer stage assembly, a one dimensional diffusion profile was measured. It was discovered that the absorbances of PS and PVT at certain wavelengths increases for several hours after the irradiation has ended when high dose rates of 6 Mrad/hour are used. It was also found that the visibly sharp annealing boundary that penetrates into the irradiated polymers consistently measured 0.03 inches wide for PS for all wavelengths between 375 and 470 nm and that therefore the oxygen induced bleaching of color centers proceeds at the same rate for all color centers in this wavelength range. A simple self-diffusion model was fit to the boundary velocity data. The self-diffusion coefficients (D 0 ) were calculated for PS and PVT: D 0 ( PS ) = 1.3 × 10 −8 cm 2 / sec and D 0 ( PVT ) = 1.7 × 10 −7 cm 2 / sec .

Rate constants and the activation energy associated with the optical recovery process of radiation-damaged poly(vinyltoluene) were measured using UV-Vis spectrophotometry and EPR spectroscopy. In-vacuo experiments showed that the recovery process is not uniform throughout the spectrum. The UV (375 nm) and the green (532 nm) regions exhibit a continued increase in damage after irradiation has ceased while the blue (480 nm) region shows a recovery typical of a bimolecular reaction that begins immediately after irradiation ceases. The activation energy for the bimolecular rate process was determined to be 110 kJ/mole. Preliminary in-situ studies indicate that this could actually be a two-step process with separate rate constants that is characteristic of a radical decay mechanism. The 480 nm absorption has been identified as a radical, probably the benzyl radical.

Quartz fiber calorimetry is a sampling calorimetry technique based on the detection of Cherenkov light generated in quartz optical fibers. Optical fibers transport only selected modes of light which results in very narrow visible showers. In addition, this technique is characterized by radiation resistance measured in gigarads and nanosecond pulse duration. The results of recent beam tests are presented, illustrating behavior of electromagnetic calorimeters based on this technique as a function of their absorber type, density and distribution of fibers and fiber types.

A series of high dose rate (20 kGy/hr) and low dose rate (<10 Gy/hr) irradiations of a large sample of plastic scintillating fibers (1 mm ø, 150 cm length) has been completed. Measurement of the transmission characteristics of the fibers have been completed and the results are presented in this report. Measurements of the loss to intrinsic scintillation output will be completed at a later date. The transmission measurements show striking features: (1) those fibers irradiated slowly in air (i.e., in the presence of oxygen) suffer the greatest level of damage, while (2) the fibers irradiated rapidly, and then allowed to recover, display the least amount of damage, and (3) fibers irradiated slowly in argon display a level of damage intermediate between the other two. One fiber, the green-emitting SCSF-Y8, is the only exception, and shows no difference in the level of damage observed in the three modes of irradiation.

The authors discuss two ways of insuring plastic scintillators against radiation damage: shifting to longer secondary fluor emission wavelengths and increasing secondary fluor concentration. They describe a scintillating-fiber-based calorimeter which can be made compensating. The calorimeter recovers its original resolution less than one month after receiving a dose of 10 Mrad via 100-MeV electrons.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Scintillating fiber electromagnetic calorimeters, with excellent resolution characteristics, have been subjected to in situ destructive radiation-damage tests in an intense beam of monoenergetic electrons. The resolution and light output of the detectors were monitored as a function of dose. The materials used to construct the module were selected for radiation hardness. The experimental procedure, the assumptions involved in the calculation of deposited dose, and the detector performance vs dose behavior are discussed.

The radiation hardness properties of a tile/fiber calorimeter with different materials or with different optical path layouts have been studied. Ten calorimeter modules of a geometry similar to that of the proposed SDC calorimeter were irradiated using the BEPC electron beam (1.1 or 1.3 GeV). Radiation damage was quantified by measuring the light yield at various locations within the calorimeter modules at different integrated doses. The recovery process and the dependence on the ambient atmosphere were also studied and correction techniques for various dose and depth profiles were developed.

Electromagnetic calorimeters which sample the Cherenkov radiation of shower particles in optical fibers operate in a markedly different manner from calorimeters which rely on the dEdx of shower particles. The well-understood physics of electromagnetic shower development is applied to the case of Cherenkov-fiber calorimetry (also known as quartz fiber calorimetry) and the results of systematically performed studies are considered in detail to derive an understanding of the critical parameters involved in energy measurement using such calorimeters. A quantitative parameterization of Cherenkov-fiber calorimetry electromagnetic energy resolution is proposed and compared with existing experimental results.

The presence of oxygen as well as thermal treatment of polystyrene prior to irradiation directly affects the susceptibility to radiation damage of this scintillator base as measured by its optical density in the ultraviolet (UV). Oxygen saturated samples have greatly decreased radiation induced absorption as compared to those stored in argon and vacuum (all samples kept at STP). Heat treatment (48 hours at 70° C prior to irradiation), decreased the susceptibility to radiation damage of deoxygenated samples (stored in vacuum/argon) in the UV range compared with those kept at 25° C. On the other hand, heat treatment increased the radiation damage of those samples saturated with oxygen that were kept at 70° C (as opposed to 25° C). Permanent induced absorptions after extended recovery in air for all four permutations were comparable.

Abstract It is shown that non-uniform doping of scintillating and wavelength shifting fibers can be used to produce the theoretical maximum light yield for any combination of fiber material and fluors. It is calculated that a threefold increase in light yield is possible. Other doping profiles may be used where high speed timing behaviour is the major objective.

The availability of commodity digital hardware: fast, cheap and standardized, makes building a high performance computing center possible for even small groups. Delays and overruns - some foreseeable, some not, will occur even when anticipated but still more if not. In the following we detail explicit procedures, tradeoffs and advice to create a several hundred core, Grid-aware Tier 3 facility such that a small research group can enjoy maximum utility of its research resources.

A television system has been incorporated into the Heidelberg PEPR-hardware1–3), which enables tn operator to digitize points on bubble chamber film with a precision of better than 10 μm. A mirror flipped into the optical path projects the film illuminated by the bright face plate of the cathode ray tube onto a television camera. The vidicon together with a reference mark created by the electron beam on the CRT-face plate may be moved to any point on the film by means of a speed ball. A PDP-10 computer controls the PEPR-device. In addition, it does automatic tracking following starting at clear points and calculates circle and vertex fits. Complicated track images may be digitized completely manually. Output consists of fiducials, up to 16 points per track, vertices and stop points. With this system we process events which failed the first measurement done with a minimum guidance system4). About 20 events in three views can be measured per hour with a success rate of about 75% after kinematical analysis. This results in an overall success rate of 95% after the second measurement.

A silicon photomultiplier, sometimes called “multipixel photon counter”, which we here refer to as a “SiPM”, is a photo-sensitive device built from an avalanche photodiode array of pixels on a common silicon substrate, such that it can detect single photon events. The dimensions of a pixel may vary from 20 to 100 μm and their density can be greater than 1000 per square millimeter. Each pixel in a SiPM operates in Geiger mode and is coupled to the output by a quenching resistor. Although each pixel operates in digital mode, the SiPM is an analog device because all the pixels are read in parallel, making it possible to generate signals within a dynamic range from a single photon to a large number of photons, ultimately limited by the number of pixels on the chip. In this note we describe a simple and general method of increasing the dynamic range of a SiPM beyond that one may naively assume from the shape of the cumulative distribution function of the SiPM response to the average number of photons per pixel. We show that by rendering the incoming flux of photons to be non-uniform in a prescribed manner, a significant increase in dynamic range is achievable. Such re-distribution of the incoming flux may be accomplished with simple, non-focusing lenses, prisms, interference films, mirrors or attenuating films. Almost any optically non-inert interceding device can increase the dynamic range of the SiPM.

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IDEA (Innovative Detector for an Electron-positron Accelerator) is a general-purpose detector concept, designed to study electron-positron collisions in a wide energy range from a very large circular leptonic collider. Its drift chamber is designed to provide an efficient tracking, a high precision momentum measurement and an excellent particle identification by exploiting the application of the cluster counting technique. To investigate the potential of the cluster counting techniques on physics events, a simulation of the ionization clusters generation is needed, therefore we developed an algorithm which can use the energy deposit information provided by Geant4 toolkit to reproduce, in a fast and convenient way, the clusters number distribution and the cluster size distribution. The results obtained confirm that the cluster counting technique allows to reach a resolution 2 times better than the traditional dE/dx method. A beam test has been performed during November 2021 at CERN on the H8 to validate the simulations results, to define the limiting effects for a fully efficient cluster counting and to count the number of electron clusters released by an ionizing track at a fixed $βγ$ as a function of the track angle. The simulation and the beam test results will be described briefly in this issue.

A general theory of optical transport systems has been developed that can be used to determine preliminary design specifications for light guide systems. Several generic light guide types are analyzed, including hollow reflective light guides, prism light guides, solid dielectric and fluid-filled light guides, lens guides, and open light wells. Minimum theoretical aperture requirements are determined for each type as a function of the specified optical transport efficiency and design parameters (light guide length, transmitted luminous flux, etc). Generally, a system's aperture requirement would be inversely related to its cost. Solid dielectric (e.g., optical fiber) light guides would be very compact and practical for retrofit applications, but their high cost option, but would require the greatest aperture area. Hollow reflective light guides, prism light guides, or lens guides may offer the best compromise between cost and space requirements. But in order to achieve optical concentrations and efficiencies near the theoretical limit, the collector system would need to maintain optical and tracking tolerances exceeding the capabilities of existing systems so further advances in core daylighting will require improvements in collector technology. 4 figs., 16 refs.

A new calorimetry technique based on shower sampling of Cherenkov light in optical fibers is presented. Fast response, excellent radiation hardness, insensitivity to neutrons, shower core detection and this technolgie's static (no gas, no liquids) properties make it an excellent candidate for Very Forward Calorimetry (VFCal) for the LHC.

The measurements of radiation damage of tile/fiber scintillator modules to be used for the Solenoid Detector Collaboration (SDC) calorimeter are described. Four tile/fiber scintillator modules were irradiated up to 6 Mrad with the BEPC 1.1 GeV electron beam, and two modules up to 1 Mrad with a 1.3 GeV beam. We have studied the light output at different depths in the modules and at different integrated doses, the recovery process and the dependence on the ambient atmosphere.

A series of high-dose-rate and low-dose-rate irradiations of a large sample of plastic scintillating fibers has been completed. Measurement results of the transmission characteristics of the fibers are presented. The transmission measurements showed striking features: (1) those fibers irradiated slowly in air suffered the greatest level of damage, (2) the fibers irradiated rapidly, and then allowed to recover, displayed the least amount of damage, and (3) fibers irradiated slowly in argon displayed a level of damage intermediate between the other two. One fiber, the green-emitting SCSF-Y8, was the only exception, and showed no difference in the level of damage observed in the three modes of irradiation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Summary form only given. Studies of plastic scintillators have shown that high dose rate exposures almost always underestimate the radiation-induced damage at low dose rates. The degree of excess damage depends in a complex manner on the dose rate, temperature, and oxygen partial pressure. Excess damage is confined to a few-millimeter-thick surface zone, a finding of especial importance for the use of scintillating or wave-shifting fibers. An important consequence of these investigations is that it is not known how to carry out accelerated aging tests. It has also been shown that the thermal and atmospheric history of a particular piece of scintillator is relevant to the amount of damage incurred by radiation. A scintillator which has been heated or kept in inert gas for several days prior to irradiation is more easily damaged. Because the chemical mechanisms which are responsible for radiation-induced color centers in the common bases polystyrene and polyvinyltoluene remain to be clarified, the best chance for near-term progress in the creation of more radiation-tolerant scintillators may be in finding new fluors which emit at longer wavelengths thus circumventing the color centers.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The electro-optical interfaces for the central and endcap calorimeters of the CMS experiment at the CERN Large Hadron Collider are readout boxes that receive optical signals via fiber-optic waveguides from the calorimeter scintillator megatiles that comprise the active elements of the detector and decode these signals for energy measurement. The phototransducers housed within the readout boxes are Hybrid Photodiodes (HPDs) which detect and amplify the optical signals. Digitization is provided by preamplifiers or by QIE (Charge, Integration, and Encode) chips. Output signals am then transmitted from the readout boxes to Trigger/DAQ systems located off-detector. Design concepts and construction details are presented for the first pre-production-prototype readout boxes.

A scintillating fiber based electromagnetic calorimeter module built from radiation-hard materials has been tested in a beam capable of delivering both low and high currents of monoenergetic electrons. Energy resolution and light output measurements were made following high-dose exposures. The procedure was repeated until the resolution of the detector decreased from an initial value of 6.9%{radical}E to 14.0%{radical}E and the pulse height dropped by a factor of 11. After four weeks, the detector was retested. Partial recovery was observed in the light output which returned to approximately 52% of its original value. The resolution recovered to a value of 8.8%{radical}E. The tests are described. 9 refs., 4 figs.

The measurements of radiation damage of tile/fiber scintillator modules to be used for the SDC calorimeter are described. Four tile/fiber scintillator modules were irradiated up to 6 Mrad with the BEPC 1.1 GeV electron beam. We have studied the light output at different depths in the modules and at different integrated doses, the recovery process and the dependence on the ambient atmosphere.

This paper reports on a series of high dose rate (20 kGy/hr) and low dose rate([lt]10 Gy/hr) irradiations of a large sample of plastic scintillating fibers (1 mm [phi], 150 cm length) which have been completed. Measurements of the transmission characteristics of the fibers have been completed and the results are presented in this report. Measurements of the loss to intrinsic scintillation output will be completed at a later date. The transmission measurements show striking features: those fibers irradiated slowly in air (i.e., in the presence of oxygen) suffer the greatest level of damage, while the fibers irradiated rapidly, and then allowed to recover, display the least amount of damage, and fibers irradiated slowly in argon display a lever of damage intermediate between the other tow. One fiber, the green-emitting SCSF-Y8, is the only exception, and shows no difference in the level of damage observed in the three modes of irradiation.