COMMISSIONING OF THE FERMILAB ELECTRON COOLER PROTOTYPE BEAM LINE

Abstract A prototype of a 4.3-MeV electron cooling system is being assembled at Fermilab as part of the ongoing R&D program in high energy electron cooling. This electron cooler prototype will not demonstrate the actual cooling but it will allow determining if the electron beam properties are suitable for antiproton beam cooling. An electron beam is accelerated by a 5-MV Pelletron (Van de Graaff type) accelerator and transported to a prototype cooling section. The cooling will take place in a 20-m long solenoid flanked on both sides by a delivery and return beam-line -a total of 60 meters of transport channel. This paper describes the first results of commissioning this novel beam line as well as the status of the electron cooling R&D program

EPICS Personal Computer Evaluation

This document is an evaluation of five personal computers to be used as intelligent terminals on the beamline control system (EPICS). It is not intended to be a general comment on the computers themselves. Rather, it is an evaluation of these computers for a specific need. Nevertheless, this document should be useful for those considering the acquisition of a personal computer

Near-field optical investigations of photonic crystal microresonators

We present an overview of our work on the application of scanning near-field optical microscopy (SNOM) to photonic crystal structures. Our results show that SNOM can be used to map the subwavelength confinement of light to a point-defect in a 2D photonic crystal microresonator. Comparison with numerical modelling shows that SNOM is able to resolve patterns in the intensity distribution that are due to the slight non-uniformity in the crystal structure. We also discuss the future possibilities for applications of different modes of SNOM to photonic crystal devices

EPICS System: System Structure and User Interface

This paper present the user's view of and the general organization of the EPICS control system at Fermilab. Various subsystems of the EPICS control system are discussed. These include the user command language, software protection, the device database, remote computer interfaces, and several application utilities. This paper is related to two other papers on EPICS: an overview paper and a detailed implementation paper

Attainment of a high-quality electron beam for Fermilab's 4.3 MeV cooler

The recent demonstration of electron cooling of antiprotons in the Recycler ring required a stable 4.3 MeV electron beam with a DC current of hundreds of mA and an angular spread in the cooling section of a fraction of a mrad. This paper describes the achieved parameters of the Fermilab cooler's electron beam and details of operation

Antiproton cooling in the Fermilab Recycler Ring

The 8.9-GeV/c Recycler antiproton storage ring is equipped with both stochastic and electron cooling systems. These cooling systems are designed to assist accumulation of antiprotons for the Tevatron collider operations. In this paper we report on an experimental demonstration of electron cooling of high-energy antiprotons. At the time of writing this report, the Recycler electron cooling system is routinely used in collider operations. It has helped to set recent peak luminosity records

Device-level characterization of the flow of light in integrated photonic circuits using ultrafast photomodulation spectroscopy

Advances in silicon photonics have resulted in rapidly increasing complexity of integrated circuits. New methods are desirable that allow direct characterization of individual optical components in-situ, without the need for additional fabrication steps or test structures. Here, we present a new device-level method for characterization of photonic chips based on a highly localized modulation in the device using pulsed laser excitation. Optical pumping perturbs the refractive index of silicon, providing a spatially and temporally localized modulation in the transmitted light enabling time- and frequency-resolved imaging. We demonstrate the versatility of this all-optical modulation technique in imaging and in quantitative characterization of a variety of properties of silicon photonic devices, ranging from group indices in waveguides, quality factors of a ring resonator to the mode structure of a multimode interference device. Ultrafast photomodulation spectroscopy provides important information on devices of complex design, and is easily applicable for testing on the device-level