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K. Jacobs, R. Averill,
S. Bradley,
A. Carter,
G. Dodson,
K. Dow,
M. Farkhondeh,
E. Ihloff,
S. Kowalski,
B. McAllister,
C. Sibley,
S. Sobczynski,
D. Tieger,
C. Tschalaer,
E. Tsentalovich,
W. Turchinetz,
A. Zolfaghari,
T. Zwa R T
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ABSTRACT: The South Hall Ring at the MIT-Bates Linear Accelerator Center is a 1GeV electron ring for nuclear physics experiments. It is designed to operate in two modes: as a pulse stretcher to deliver high duty factor beams to external targets, and as a storage ring for internal target experiments. To date we have injected beam into the ring using one and two-turn injection, stored beam with a lifetime of several minutes, and achieved early results performing half-integer resonant extraction from the ring in pulse stretcher mode. Experience in commissioning the ring is presented. Future plans for extraction, improved storage and backgrounds, and spin control and measurement in the ring, are also discussed. I. INTRODUCTION The South Hall Ring (SHR) at the MIT-Bates Linear Accelerator Center is now being commissioned. It is an electron stretcher/storage ring designed to serve nuclear physics experiments in two ways: as a pulse stretcher ring, converting the 1 % duty factor beam from the Bates l...
04/1998;
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ABSTRACT: A scientific collaboration between MIT-Bates and the Budker
Institute of Nuclear Physics (BINP) has produced a design for a magnetic
insertion, aka “Siberian Snake”, into the SHR lattice, which
allows for spin control of 0.3 to 1.0 GeV polarized electron beams for
planned internal and external target physics. This report describes the
design, construction and testing at BINP and the final testing at
MIT-Bates for the two superconducting solenoids, which make up part of
the “Snake”
Particle Accelerator Conference, 1997. Proceedings of the 1997; 06/1997
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ABSTRACT: A water-cooled Faraday cup has been installed at the Bates Linear
Accelerator Center in order to measure the extracted beam current from
the pulse-stretcher ring in the South Experimental Hall. The Faraday cup
is designed to dissipate 100 kW of heat and is thus well-matched to the
beam characteristics of Bates (50 μA at 1 GeV). The device has been
placed on a cart-and-rail system so that it can be remotely driven into
and out of the beam line. We expect the Faraday cup to serve as an
absolute calibration source for beam current measurements to better than
0.1% accuracy. This will allow for very high precision cross section
measurements and the isolation of small interference response functions
with reduced systematic uncertainty
Particle Accelerator Conference, 1997. Proceedings of the 1997; 06/1997
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ABSTRACT: Power demand charges to MIT-Bates are based on a fixed rate times
the greater of kWatt or 0.9 (kVolt A) called for in a 15 minute period
within a billing cycle. There have been a number of months in a year
when the power factor (PF) was less than 0.9 lagging, resulting in the
increase in the demand charges to MIT by the Middleton Municipal
Electric Department (MMED). A study resulted in a decision to correct
the PF to >0.9 in order to minimize the demand charges. This action
would save about $3500 per month in demand charges. Other benefits would
also be realized by MIT-Bates and MMED, depending on the installation
location. Information obtained on operational AC power requirements for
the pulsed loads was obtained by measuring current and voltages at the
480 V inputs to the pulsed loads and at the incoming 22,900 V line input
to the facility. A review of the harmonics generated in the voltage and
current waveforms at both voltage levels for several operating levels
allowed completion of an engineering analysis, which resulted in the
selection of a 1200 kVAR switchable capacitor bank to be installed in a
wye connection at the 22,900 V incoming line point just after the
metering equipment. This paper describes the results of the harmonic
studies of the AC power, the pulsed loads required as measured at 480 V,
and the resultant overall harmonics generated at the 22,999 V level by
the pulsed loads when combined with the other normal AC loads at the
Laboratory
Particle Accelerator Conference, 1997. Proceedings of the 1997; 06/1997
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K. Jacobs, R. Averill,
S. Bradley,
G. Dodson,
K. Dow,
M. Farkhondeh,
S. Kowalski,
B. McAllister,
D. Tieger,
C. Tschalaer,
E. Tsentalovich,
W. Turchinetz,
F. Wang,
A. Zolfaghari,
T. Zwart
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ABSTRACT: The South Hall Ring at the MIT-Bates Linear Accelerator Center is
a combination of pulse stretcher ring to produce high duty factor
extracted beams and storage ring for use with internal targets. It is
designed to operate at energies from 300 MeV to 1 GeV for nuclear
physics experiments. In pulse stretching mode, half-integer resonant
extraction is used to convert the <1% duty factor beam from the linac
into near CW beam. To date, we have extracted beams with duty factors in
excess of 50%, and high throughput efficiencies. The first nuclear
physics experiments using extracted beam are planned for the near
future. Details of commissioning the ring for extracted beam operation
are presented
Particle Accelerator Conference, 1997. Proceedings of the 1997; 06/1997
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K. Jacobs, R. Averill,
S. Bradley,
A. Carter,
G. Dodson,
K. Dow,
M. Farkhondeh,
E. Ihloff,
S. Kowalski,
B. McAllister,
W. Sapp,
C. Sibley,
S. Sobczynski,
D. Tieger,
C. Tschalaer,
E. Tsentalovich,
W. Turchinetz,
A. Zolfaghari,
T. Zwart
[show abstract]
[hide abstract]
ABSTRACT: The South Hall Ring at the MIT-Bates Linear Accelerator Center is
a 1 GeV electron ring for nuclear physics experiments. It is designed to
operate in two modes: as a pulse stretcher to deliver high duty factor
beams to external targets, and as a storage ring for internal target
experiments. To date we have injected beam into the ring using one and
two-turn injection, stored beam with a lifetime of several minutes, and
achieved early results performing half-integer resonant extraction from
the ring in pulse stretcher mode. Experience in commissioning the ring
is presented. Future plans for extraction, improved storage and
backgrounds, and spin control and measurement in the ring, are also
discussed
Particle Accelerator Conference, 1995., Proceedings of the 1995; 06/1995
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ABSTRACT: The MIT-Bates South Hall Ring (SHR) is an electron storage ring
currently being commissioned. It is designed to operate at an RF
frequency of 2856 MHz with all of the 1812 buckets filled and a
circulating current of 80 mA or greater. This leads to a small charge
per bunch and the requirement for beam position monitors. Since there
will be 31 such monitors in the vacuum system, it is important to
suppress trapped modes which may excite coupled bunch instabilities. The
stripline monitor built for the SHR is a stainless steel structure,
designed to be manufactured using standard machining techniques and
commercial feedthroughs. With proper 50 Ohm matching and a geometry
derived from insight from MAFIA calculations, the monitor was
constructed having a nearly flat RF response up through 10 GHz over the
range of measurement. The stripline electronics allows the measurements
with 0.1 mm resolution, maintains orbital harmonics information past the
10th harmonic, and operates over a dynamic range of 1 mA to greater than
80 mA of beam current
Particle Accelerator Conference, 1993., Proceedings of the 1993; 06/1993
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ABSTRACT: The MIT-Bates Linear Accelerator Center is now in the
commissioning stage for the new South Hall Ring (SHR). The SHR is a 1
GeV electron storage/stretcher ring with a 190 meter circumference and
is designed for circulating beams of 80 mA. The SHR vacuum system was
completed in January 1993 with commissioning starting in February. This
paper describes the design of the vacuum system, hardware developed and
operational performance during commissioning
Particle Accelerator Conference, 1993., Proceedings of the 1993; 06/1993
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ABSTRACT: This report discusses the design, construction, testing and
installation of 2 magnetic septa in the South Hall Ring Lattice for the
injection and extraction of an electron beam of energies from 0.3 to 1.0
GeV. The report covers: magnetic design and performance of the
following; steel return frame, electrical coil design, power supply,
vacuum vessel supports, fiducialization, and magnetic measurements
Particle Accelerator Conference, 1993., Proceedings of the 1993; 06/1993
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ABSTRACT: This report discusses the design and performance of 2 Ramped
Quadrupoles (RQ). They are to be used to rapidly move the horizontal
tune close to the half integer (7.5) for extraction of the up to 1.0 GeV
electron beam stored in the SHR. The design chosen is an 8 conductor
array symmetrically placed about the beam axis at ±15° to the
4 axes and connected to produce a quadrupole field. The conductors are
half imbedded in a ferrite shield assembly, outside a ceramic vacuum
chamber, and when powered at 250 amperes produce a gradient of about 30
G/cm over the radius of 4.5 cm and along a 30 cm length. The ceramic
chamber is internally conductively shielded to present a smooth bore
surface for the S-band bunches, but allow the up to 20 kHz quadrupole
field components to pass through the shield and influence the electron
beam
Particle Accelerator Conference, 1993., Proceedings of the 1993; 06/1993
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ABSTRACT: The MIT-Bates South Hall Ring (SHR) is an election storage ring
undergoing commissioning. Electrostatic septa are used to inject
electrons into and resonantly extract electrons from the ring. This
report describes the engineering design and performance achieved for 2
electrostatic septa constructed with 270, 50 micron thick, 5 mm wide
molybdenum foils stretched over a long precision machined, C-shaped
carrier. The septa gaps are 2 cm and are designed to operate at 50 kV/cm
over their 1.5 m effective lengths to produce a 7.5 mr horizontal bend
for 1.0 GeV electrons
Particle Accelerator Conference, 1993., Proceedings of the 1993; 06/1993
