Fermilab History and Archives Project

Fixed Target Program - Proton Area

The Proton Pagoda, with its double-helix stairway, sits atop the Proton Laboratory
Excavation of the Proton Area (September, 1971) The Proton Laboratory of the Fixed Target Area (August, 1976) The Proton Laboratory of the Fixed Target Area (July, 1979)

THE PROTON PAGODA MODEL

Don Moll

Don Moll, DUSAF Project Architect, studies a model of the "Proton Pagoda," a new building now being designed for the NAL Proton Area. The two-level steel and glass structure is pierced by a cylinder, 10 feet in diameter, containing two intertwining curving steel stairs. The upper level, 24 feet square, contains an operations center for the Proton Area. It sits 40 feet above grade and affords a commanding view of the Proton Area. Access will be from a parking lot on the south side.

Source: The Village Crier Vol. 5 No. 15, April 12, 1973

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PROTON AREA BEGINS STUDY OF HIGH ENERGY PROTONS

The rugged structure of NAL's Proton Area

The rugged structure of NAL's Proton Area

The scientific sleuths who observe the puzzling behavior of the subatomic particles in a proton beam are setting up some intricate equipment in NAL's Proton Area which they hope will soon take some of the mystery out of these remote aspects of physical matter. Seen from the air, the corridors of the Proton Area are a huge, gaping labyrinth - rectangular pits typically 25 feet wide, 20 feet in depth, walled by massively-corrugated sheet steel pilings, woven into a where-does-it-end? pattern. Seen from the ground, the stark plainness of the structures and the intricate paths of the beam lines reveal that the people who worked here were preparing for something unusual in the way of particle reactions.

On November 3, 1972 a beam of 200 BeV protons was steered out of the main accelerator, through the switchyard, and cleanly down the proton experimental line which is the east-most line of the three-pronged external experimental switchyard. Focussing on a tungsten target 1/8" in diameter, that first beam was seen in the P-Central area. Within 50 feet on either side are P-West and P-East, the other two places where experimental work was carried on.

In addition to bringing the line into operation, the event also represented the complete activation of the NAL experimental areas - the Meson and Neutrino lines having previously come on the air in the past few months.

Layout of the NAL Proton Area showing location of the first six experiments to be performed there
Layout of the NAL Proton Area showing location of the first six experiments to be performed there

Construction of the P-Central experimental pit. Light-colored box at rear center contains target box
Construction of the P-Central experimental pit. Light-colored box at
rear center contains target box

The reason for the careful plotting of the Proton Area design is two-fold - to accommodate requirements of the particular kind of experiments that will go on there and to retain a great deal of flexibility so that re-arrangements of the accommodations can be accomplished easily, allowing other experiments to move in quickly when the current ones have finished. The pits which contain the experimental equipment are covered with hatched, removable roofs. New experiments will add to or change these pits. A service building, which also contains the access shaft to the labyrinths, is located above the ground.

WORKING IN THE PROTON SECTION

Ed Tilles (L), Lincoln Read
Ed Tilles (L), Lincoln Read
A. Guthke (L), Frank Juravic, and John Peoples
A. Guthke (L), Frank Juravic, and John Peoples
(L-R) Stan Orr, Larry Tate, Bob Scherr, J. Guerra
(L-R) Stan Orr, Larry Tate, Bob Scherr, J. Guerra

Photos by Tim Fielding, NAL

In the Proton Area, experimenters study the collisions on targets of protons which come directly from the accelerator - in contrast to the other NAL experimental areas which study secondary beams - that is, beams of particles which are first produced from collisions on targets in the particular area, then transported for study. Experiment Number 70, for instance, has already begun in the Proton Area. It is a collaboration of Columbia University, Rockefeller University, and NAL experimenters to be carried out in three phases - measurements of the production of (1) gamma rays; (2) electrons, and (3) pairs of electrons and positrons. The numbers of these particles produced as the proton beam strikes targets and the energies carried off by the new particles will be measured at a variety of angles. Data will be closely scrutinized for possible existence of exotic new particles suggested in recent years, such as the W "intermediate weak boson" or Bo "heavy photon." Five other experiments are to be housed in the Proton Area in this first wave of experimenting there, all searching for new phenomena.

Physicist Lincoln Read has directed the development of the Proton Area in the last several months. Many of the conceptual ideas for the design originated with Al Maschke. "The backbone of our effort has been the determined work of a small group of people who have been working on this project since last February," according to Dr. Read. "This includes Ron Currier, Dave Eartly, Dean Lee, Alice Lengvenis, Bob Scherr and Ed Tilles. During the intervening months, many others have entered the fray - Jesse Guerra, Al Guthke, Bettie Howe, Frank Juravic, Del Hoffman, Ed LaVallie, Tom Nash, Lou Nouzak of Technical Services, Stan Orr, John Peoples, Bob Shovan, Larry Tate, and Aage Visser.

"They have all contributed enthusiastically toward getting Proton Central operational. Everyone is now working very hard toward achieving a second important milestone in the Proton Area - the start of beam operations in Proton East, which we hope to achieve in December. Early next year. Experiment Number 100 (in Proton East), which is being done by physicists from Princeton University and the University of Chicago, can then begin.

"The people in the Proton Section are only partly responsible for the fact that the Proton Area is now coming into operation for experiments," Read said. "Our appreciation goes to all the other groups at NAL and DUSAF whose help and cooperation has been enormously important."

Source: The Village Crier Vol. 4 No. 35, November 16, 1972

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PROTON AREA OPENS PAGODA CONTROL CENTER

Aerial view of Proton experimental area. Pagoda control center may be seen at right
Aerial view of Proton experimental area. Pagoda control center may be seen at right

The Pagoda
The Pagoda

The last major component in the original design of the Proton Experimental Area was formally opened this week. The Pagoda housing the control center for the Proton Area was launched by the twist of a dial by Director Robert R. Wilson at a noon-hour ceremony Wednesday, February 25, 1976.

The Pagoda is glassed on four sides and rises some 30 feet from the ground, making it the best place from which to see the entire outlying experimental areas. From the vantage point of the control deck of the Pagoda a 360° view is possible. But the three experimental halls controlled from the Pagoda -- P-East, P-Center, and P--West -- lie buried deep underground.

The Proton Area takes the primary proton beam from the accelerator with full intensity and energy. Experiments using the primary proton beam are located in three pits, identifiable at ground level only by the scalloped roofs over the top of what is actually a giant labyrinth. Two secondary beams are also generated by the Proton Area, the tagged photon beam and the broad band photon beam. Three crews of operators work around the clock in the Pagoda guiding the beam from the accelerator into the Proton Area facilities and into the three experiments running here simultaneously.

Direction of the Proton Area changed hands this week as Brad Cox became Proton Department Head, succeeding Roy Rubinstein who had held the position for the past 12 years. During this period, the Area has grown considerably; it also has changed its main emphasis from construction to operation for physics experiments, of which there are now eight set up. The Tagged Photon Laboratory with its associated electron beam was brought into use; the three-way-split became operational, followed by operation of the quadrupole enclosures, and the use of the P-West Area for experiments. Several important physics discoveries have already been made in the Proton Area.

In the next few months the Proton Department will start construction of a High Intensity Pion Laboratory that will be an extension of the P-West line. The new line will contain 54 superconducting magnets -- the first superconducting beam line at Fermilab.

New view of Meson Detector Building as seen from the Pagoda
New view of Meson Detector Building as seen from the Pagoda
Two interlaced spiral staircases lead up to control center
Two interlaced spiral staircases lead up to control center

(L-R) Roy Rubinstein, retiring head, Brad Cox, new head of Proton Area

(L-R) Roy Rubinstein, retiring head, Brad Cox, new head of Proton Area

Crew chief Tom Prosapio describes operation of control panels

Crew chief Tom Prosapio describes operation of control panel

Source: The Village Crier Vol. 8 No. 9, March 4, 1976

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PROTON AREA EXPANDS

Major addition planned for Proton Area
Major addition planned for Proton Area

The Proton Experimental Area broke ground last week for a major addition to the experimental facilities there. Known as the "Pion Area," the new facility will be situated downstream of the existing Proton West experimental area. It will provide Fermilab with a major capability for experimentation with pion and anti-proton beams of intensities and of energies available at no other laboratory, and with an electron beam with excellent spot size, intensity, and purity at energies far above that available at electron machines.

According to Brad Cox, head of the Proton Area, Phase I of the construction will see completion in June of 1977 of the farthest end of the new laboratory to the middle; Phase II will include the targetting station, the portion adjacent to P-West. More than 50 superconducting magnets will be built for the line, similar to those being developed for the Energy Doubler.

The new area will receive particles of 500-1000 BeV and with intensities as high as 1014 protons per pulse at 500 BeV. In response to the growing ecperimental interest, it will be possible in the new area to study low cross sections which produce rare effects and particles such as the psi family.

Breaking ground for Pion Area: (L-R) R. Wilson, J. McCook, J. Peoples, E. Goldwasser, B. Cox, and D. Jovanovic
Breaking ground for Pion Area: (L-R) R. Wilson, J. McCook, J. Peoples, E. Goldwasser, B. Cox, and D. Jovanovic

Source: The Village Crier Vol. 8 No. 24, June 24, 1976

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GROUNDBREAKING FOR HYPERON AREA

Hyperon groundbreakers are (L-R): J. MacLachlan, S. Sollit, J. Lach, R. Majka, R. Wilson, T. Murphy, E. Steigmeyer and R. Carrigan
Hyperon groundbreakers are (L-R): J. MacLachlan, S. Sollit, J. Lach, R. Majka, R. Wilson, T. Murphy, E. Steigmeyer and R. Carrigan
R. Majka (L) looks on as Fermilab Director R. Wilson opens groundbreaking ceremonies
R. Majka (L) looks on as Fermilab Director R. Wilson opens groundbreaking ceremonies

Friday, August 26, was a hot, humid day. Rain clouds had been gathering since early morning. At precisely 3 p.m., Mother Nature emptied the heavens.

The cloudburst is hardly news ... but this one coincided with groundbreaking ceremonies for a charged hyperon beam enclosure in the proton experimental area.

Dampened, but not dismayed, Laboratory Director Robert R. Wilson got the event underway with brief remarks and turned the first shovel of earth. Then shovels were wielded by: Thornton Murphy, head of the Proton Department; Joe Lach, proton department and spokesman for E-497; Dick Majka, Yale University; Dave Eartly, project physicist for Proton Center; Dick Carrigan, Research Division; and Sumner Sollit, president of the construction firm. The participants walked out of ankle-deep mud to light refreshments provided by Yale.

The construction of this new enclosure just downstream of the present proton center enclosure will house a new charged hyperon beam. The first experiment using this beam is E497, a joint Fermilab-Yale University collaboration. Hyperons are baryons like the familiar proton and neutron that make up most of the matter around us, but with one or more of the three normal quarks which make up these particles replaced by strange quarks. The new area is a concrete enclosure 190 feet long by 18 feet wide. It will connect onto the present PC enclosure. The extension is designed to be straddled by the Proton department travel lift which will service it through removable roof hatches. The project is due to be completed in about 90 days. Although the first set of experiments in this area will use charged hyperons, other future experiments will also benefit from having such a long enclosure.

This new enclosure will serve as a staging area for E497; providing a complex spectrometer for identifying hyperons through their decay products that can be built and tested while the present program in Proton-center concludes.

Hyperon extension to Proton Center shown in relation to present PC pit and proposed spectrometer/trigger counters

Hyperon extension to Proton Center shown in relation to present PC pit and proposed spectrometer/trigger counters

 

Then the large hyperon targeting magnet will be installed. The first experiment, E497, will investigate the strong interaction of hyperons by measuring their elastic scattering properties.

Hyperons are produced by the 400 GeV proton beam striking a target. Because hyperons have very short lifetimes (10-10 - 10-11 seconds) their charge and momentum have to be determined in a very short distance. This will be done by a high field magnet which will also shield the apparatus from the unwanted interactions of the proton beam.

This magnet will be one of the largest at Fermilab, having a field of 35 KG and weighing 350 tons. The hyperon beam coming out of this magnet will be capable of having about 105 Σ¯, 103 Ξ¯ and 10 Ω¯ hyperons emerge per accelerator pulse. These hyperons contain 1, 2, and 3 strange quarks respectively. These intensities are far in excess of existing hyperon beams.

The Ω¯ is the "strangest" of all composed entirely of strange quarks. Since it was discovered in 1964 less than 100 have been observed. By comparison, the famous ψ and ψ' and even the recently discovered upsilon at Fermilab have been observed much more often.

The new hyperon area will provide beams of particles which contain no strange quarks (like pions and protons) to particles which contain three. It will be ideal for studying how the properties of baryons depend on their strangeness content.

There has been much recent excitement with the discovery that elementary particles exist which contain a new "charmed" quark. Much effort is being expended in studying the role of the charmed quark in our zoo of particles. But many theorists, such as Fermilab's Harry Lipkin, point out that we still have a very poor understanding of the role that the strange quark plays in the structure of elementary particles. Hyperons may provide important clues in unraveling these mysteries.

Source: The Village Crier Vol. 9 No. 35, September 8, 1977

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