Three nuclear particle accelerators operate
in support of the Nuclear Science Laboratory of ISNAP. The largest
accelerator on site is the model FN Tandem Van de Graaff accelerator,
which is capable of reaching acceleration voltages in excess of 10.6
MV. This accelerator is used to accelerate a wide variety of ion beams
to energies that range from a few MeV to more than 100 MeV. Most of
these ion beams are produced by a standard Sputter Ion Source (SNICS),
with helium beams being produced using a separate duoplasmatron Helium
Ion Source (HIS). In addition to the continuous, or DC, beams available
from these sources, experimenters may also choose to bunch and pulse
the beams. The buncher/pulser system is capable of producing beam
pulses of about 1.3 nsec width, separated by 100 nsec (or by some
multiple of 100 nsec using the pulse selector).
The accelerated beams from the FN Tandem
can be delivered to any one of 10 different experimental target stations,
located in two separate target rooms. There are several target stations
which can be used for general purpose experiments, and one of these
stations contains a large (1.5m) diameter scattering chamber (known
as R2D2) suitable for a wide variety of applications. In addition,
one of the target stations is a dedicated radioactive nuclear beam
(RIB) facility, containing two large superconducting solenoid magnets
used in the production of exotic, short-lived radioactive nuclear
beams such as 6He, 8Li, etc.
ISNAP also contains a model KN Van de Graaff
accelerator, with a maximum accelerating voltage of 4.0 MV. This accelerator
is capable of producing high intensity positively charged, low-mass
ion beams, and is well suited for the experimental nuclear astrophysics
research program within the laboratory. The KN accelerator facility
is, at present, completely separate from the FN Tandem facility, with
a separate target room and dedicated target stations. This facility
is also used in support of the PIXE program of material analysis.
Lastly, an even smaller accelerator, a
model JN Van de Graaff accelerator, is also available for use in our
experimental programs. This accelerator is capable of operation at
voltages of 1.2 MV and below, and can supply the high intensity, positively
charged, low mass particle beams necessary to support the experimental
nuclear astrophysics program to measure astrophysical S factors at
low energy. This accelerator facility shares the target room and experimental
target stations of the KN accelerator, since current plans envision
operating both accelerators (though not simultaneously) during several
experimental runs.
