M. Harrison

Performance of a Segmented Hadron Calorimeter

Results on the performance and details of the design of an iron-scintillator hadron calorimeter are presented. A full absorption array of 87 calorimeter modules was assembled and tested at Fermilab. The central core of this array consisted of 48 modules with 2.8 cm iron sampling thickness by 10-13 cm width arranged in towers of modules three deep along the beam (shower) axis for a total of about 8 absorption lengths. The energy resolution of the calorimeter is given by 30%/¿E for electrons and 92%/¿E for hadrons. This resolution is compared with previous results and is found to be in good agreement with the expected resolution for this sampling thickness. The position resolution for single hadron showers is about 2 cm.

Mechanical Design of Lambertson Magnets for Injection into the Energy Saver

The design concept adopted for injection Lambertson magnets for Fermilab Energy Saver is described. The features discussed are lamination stacks and vacuum system.

Tevatron Satellite Refrigeration Control Subsystem

Refrigeration for the Tevatron is provided by 24 satellite refrigerators distributed around the ring and a Central Helium Liquefier which acts as a reservoir of liquid helium. The 24 satellite refrigerators are designed to operate as independent entities without attendant personnel. Remote control and monitoring from the main control room of the accelerator is made possible via a high speed link which allows information exchange with the central host computer. Local control is achieved by means of 24 individual self-cycling microprocessor systems which allow automatic local operation of each refrigerator. Satellite refrigerator control hardware and software are discussed. 3 refs.

Operation of the Tevatron Extraction System

The Fermilab Tevatron is currently in the middle of its second running period for fixed target physics. Steady operation has been established at 800 GeV with 1 × 1013 protons being extracted. Beam spill over the 20 - 23 second flattop is regulated by a closed loop feedback and a feed forward learning system controlled by a microprocessor.1 Eight power supplies have their waveforms programmed by the microprocessor in an attempt to reduce the modulation on the beam spill. In addition the microprocessor can insert a pause in the slow spill and cause the extraction of a high intensity (3 × 1012) fast (1-2 milliseconds long) pulse. A description of the extraction system as well as analysis of the spill modulation encountered during commisssioning are presented in this paper. Current status of the spill structure is also discussed.

FNAL Main Ring to Energy Saver Antiproton Transfer System for Tevatron I

A system for antiproton beam transfer from the Main ring to the Energy Saver for colliding beam operations has been designed and fabricated. The system is similar to the existing proton beam transfer system used for fixed target operation of the Energy Saver. Using a fast kicker in the Main Ring, one or several bunches of 150 GeV pbars will be kicked horizontally across the septa of two Lambertsons into a short transfer line. At the end of this line, they are injected into the Energy Saver through two more Lambertsons and kicked onto a closed orbit by a second fast kicker. For commissioning and tune-up, the system will be operated in reverse, extracting 150 GeV protons from the Energy Saver to the Main Ring. In addition to a description of the design of the system and its components, the status of the installation and commissioning will also be discussed.

Proton Extraction and Transport for Pbar Production in Tevatron I

The design, fabrication, and commissioning of the extraction and beam transport systems required for pbar production for the FNAL Antiproton Source will be described. The extraction system utilizes a fast kicker and Lambertson septum magnets to extract in a single turn one booster batch of 120 GeV protons from the FNAL Main Ring. The extracted beam is transported a distance of 174 m by a beam transport system consisting of 12 dipoles and 14 quadrupoles. The last 8 quadrupoles are configured as 4 pairs which focus the beam to a small round spot (radius 0.4 mm) on a pbar production target. The extraction channel is also designed to inject 8 GeV cooled pbars from the Accumulator Ring into the Main Ring, or extract 8 GeV protons from the Main Ring for diagnostic and tune-up work in the Antiproton Source beam lines and rings.

Lambertson Magnet Design for the Tevatron Extraction Channel

The beam splitting requirements of the Tevatron extraction system necessitated the design of two different high field (11 kG and 15 kG) magnetic septa. We present details of the magnet design with emphasis of the construction techniques used to achieve good vacuum behaviour and septum straightness while maintaining magnetic field quality.

Development and Performance of a Calibration System for a Large Calorimeter Array

Experiment 609 at Fermilab is a study of the properties of high-p/sub t/ collisions using a large segmented hadron calorimeter. The calibration and monitoring of such a large calorimeter array is a difficult undertaking. This paper describes the systems developed by E609 for automatic monitoring of the phototube gains and performance of the associated electronics.

Large Dynamic Range Beam Profile Measurement in a High Background Environment

Beam profile measurements using a scanning target and loss monitor in the Fermilab Main Ring extraction channel have long proved their usefulness as a diagnostic method in analyzing extraction problems. To extend these measurements to a sensitivity greater than in the present system a different technique has been employed. A simple three element particle telescope viewing the scanning target allows a sensitive measurement of the tail on the edges of the beam profiles as well as the relative particle densities of the extracted beam and the circulating beam in the Main Ring. Both these regions are of significant interest in understanding extraction losses. The details of the profile measurement technique, some results using the telescope and possible methods of improving the measurements are discussed.