CRYRING@ESR - Facility for Antiproton and Ion Research

24 Chapter 6. Proposed Construction Cycle
6.4.3 Electricity
The extension area of the new cave requires the installation of additional lighting. It would
be worthwhile to increase the brightness in the cave by means of coating the rough concrete
surface with white paint. This would also improve the cleanliness in the cave with respect to
the requirements during the opening and assembly of UHV components.
The mains voltage distribution and 3-phase line connectors have to be installed along ring
and beam lines. The total power loss of the installed heat jackets for the UHV baking system
would require 210 kW. However, baking will be done partially, i.e. sector by sector. Therefore
a line connection for a maximum consumption of about 100 kW in the cave will be sufficient.
6.4.4 Others
The technical infrastructure of Cave B can be almost unchanged from its present configuration.
The walls, where air conditioning and electric lighting are mounted, will not be dismantled.
The same applies for the walls bearing the runways for two cranes, which are required for the
transport of heavy loads inside the cave.
The connection to the pressurized air and dry nitrogen systems is already available in the
existing Cave B. The distribution in the new cave is only a small fraction of installation cost
and activities.
The planning of a false floor for the installation of the power converters will be done as
soon as a detailed arrangement of the supplies has been worked out. It has to be investigated,
whether an impounding basin for the cooling water will be necessary or not. The same is the
case concerning the required impounding basin for the oil-filled transformers. Their position,
inside or outside the Target Hall, on the upper or the ground floor, will be decided after working
out the arrangement of all supplies.
6.5 Fast ESR Beam Ejection and Transport to CRYRING
The CRYRING can be supplied with decelerated ions from the ESR. The option of decelerating
ions to 4 MeV/u is routinely used in combination with the HITRAP decelerator which is designed
for an injection energy of 4 MeV/u. The ESR cycle has been optimized for this extraction energy.
As the operation of the ESR is flexible the beam can be decelerated to other energies as well.
The beams which are available are highly charged stable ions, but also rare isotope beams
from the fragment separator FRS can be injected and decelerated. An injection energy into
the ESR of 400 MeV/u is favorably chosen in order to profit from the availability of stochastic
cooling which is optimized for this energy. At this energy for all ions stripping to the bare
charge state is achieved with high efficiency. For lower charge states the injection energy can be
reduced. Cooling after injection at lower energies can be performed by electron cooling which
is slower for hot beams, but has also been used in many ESR experiments and which results in
even better condition for deceleration. The injection energy of 400 MeV/u is sufficiently high
for the production and storage of rare isotope beams which need an even higher primary beam
energy due to the use of thick production targets and the energy loss in the target.
Independent of the injection energy the standard ESR deceleration cycle employs electron
cooling at an intermediate level of 30 MeV/u. The cooling provides best conditions for efficient
deceleration and the intermediate flat top in the magnetic cycle is used for changing the rf
frequency from harmonic number h = 2 to h = 4. This change is necessary due to the limited
frequency tuning range of the rf system. The deceleration to 4 MeV/u is done with harmonic
number h = 4. At 4 MeV/u electron cooling is applied again in order cool the beam to small
emittance and momentum spread which eases the transfer to a subsequent accelerator.