Note added 4/17/01:
Mass difference calculator
has been added to aid your beam contamination estimations.
As announced in the last HRIBF Newsletter
proposals to be submitted to the Program Advisory Committee
must be received on or before May 4, 2000.
Detailed instructions including important dates may be found on our
website. A list of
including expected intensities is also available.
major experimental endstations and on
may be found in previous HRIBF Newsletters. The
membership of PAC-6 is also available.
We encourage you to contact us with
suggestions for the beams you require to pursue your physics research.
Parameters as to what constitutes a suitable beam for the HRIBF
are found in our newsletters.
We ask that you need to be aware that scheduling experiments at our
facility is difficult. In some cases such as transfer experiments, suitable
equipment is not yet in place to take full advantage of the allocated
beam time. In other cases, sufficiently many experiments must be available
before it is "cost effective" to schedule a particular RIB ion source
or endstation configuration.
Additional information reflecting the present status of equipment and
techniques is provided below.
- Neutron-rich RIB Development - Isobarically pure Br and I beams
We presently plan to provide isobarically pure beams of Br and I isotopes
during the next scheduling period. Purity is achieved by chemically
separating these isotopes using surface ionization
(LaB6) and directly producing
negatively charged ions. Expected intensities may be found in a
table on our website.
- Beam contamination continuously sampled via X-ray detection
We have recently utilized X-rays to sample the isotopic components of a
neutron-rich beam of mass 128 at approximately 2.3 MeV/nucleon.
Data determining the amount of Sn, Sb, and Te isotopes and a sketch of
the set-up is
provided on our website. This technique for monitoring changes in
the beam components
should be fairly universal for accelerated beams. Detection efficiency
is limited so this technique is not possible on an event-by-event basis.
- Batch-mode source
As outlined in the
Winter 2001 newsletter problems arose with the production of
56Ni beams using the batch-mode source which is
designed for long-lived species. These problems are not resolved and we
do not encourage at this time proposals requiring this beam. The source
did perform as expected with 18F; however,
the KENIS has better yield for this beam.
- Silicon strip detector array for HyBall
A 288-channel silicon strip detector array is presently being constructed
and will undergo commissioning tests during the next scheduling period.
Compatible with the present CsI detector array (without the forward two
rings of detectors; 7-29 degrees in the lab), this system may be used
in dE-E telescope configuration with 150 and 400 micron thick detectors.
At present, we do not think it suitable to accept additional experiments
(e.g. transfer experiments) until this device is ready.
- Windowless gas target system
The windowless gas target system has undergone offline tests and has attained
a thickness of 5x1018 He atoms. Tests
and ES&H reviews will need to be completed before hydrogen gas may be
used and the system available for outside users. It is not anticipated
that we will accept experiments requiring this system.
- DRS commissioning
The DRS will undergo further commissioning tests during this period
to improve the overall system transmission and to test new configurations
of the target station (including the windowless gas target system)
and focal plane components.
- Microchannel plate plus foil detectors
We are in the process of acquiring more microchannel plate (MCP) detectors
for use as beam counters (suitable up to 1-4 MHz) and position sensitive
focal plane detectors. In some cases, these detectors are built with removable
foils so that they do not adversely impact beam quality when not needed.
- Silicon "telescope" for decay experiments
A large area silicon detector has been added behind the double-sided silicon
strip detector for charged particle radioactivity experiments. This detector
has been incorporated into the digital processing data acquistion system
and is typically used to detect beta and beta-delayed proton events.