BNL, Upton, Long Island, New York
MIT, Middleton, Massachusetts
The design status of the high luminosity electron-ion collider, eRHIC, is presented. The goal of eRHIC will be to provide collisions of electrons and possibly positrons) on ions and protons in the center-of-mass energy range from 25 to 140 GeV, at luminosities exceeding 1033 cm-2s-1. A considerable part of the physics program calls for a high polarization level of electrons, protons and He3 ions. The electron beam is accelerated in a recirculating energy recovery linac. Major R&D items for the electron beam include the development of a high intensity polarized source, studies of various aspects of energy recovery technology for high power beams and the development of compact magnets for recirculating passes. In a linac-ring scheme the beam-beam interaction has several very specific features which have to be thoroughly studied. In order to maximize the collider luminosity, several upgrades of the existing RHIC accelerator are required. Those upgrades may include the increase of total beam intensity as well as transverse and longitudinal cooling of ions and protons.
Jefferson Lab, Newport News, Virginia
TRIUMF, Vancouver
A conceptual design of a ring-ring electron-ion collider based on CEBAF with a center-of-mass energy up to 90 GeV at luminosity up to 1035 cm-2s-1 has been proposed at JLab to fulfil science requirements. Four interaction points on two crossing straight sections of Figure-8 shape rings are planed for collisions of both highly polarized electron and light ion beams. The Green field design of the ion complex including electron cooling and new way of organizing interacting regions are directly aimed at full exploitation of science program. Here, we summarize design progress including collider ring and interaction region optics with chromatic aberration compensation. Stacking of ion beams in an accumulator-cooler ring, beam-beam simulations and a faster kicker for the circulator electron cooler ring are also discussed.
GSI, Darmstadt
The double synchrotron complex SIS100 and SIS300 is the central part of the FAIR project. SIS100 is a fast ramped superconducting synchrotron optimized for high intensity, low-charge state heavy ion operation. However, similar to the existing heavy ion synchrotron SIS18, SIS100 will also be used to accelerate all other ion species down to protons, In order to enable such a flexible operation and to avoid transition energy crossing, a triplet structure with three independent power circuits has been chosen. For the low charge state operation, a new lattice design concept has been applied which provides an optimized separation of ionized beam particles. Low charge state operation is enabled by means of the cryopumping of the actively cooled, thin wall vacuum chambers. The stability of the residual gas pressure is an essential precondition for this operation. The project status and the status of the major device developments will be presented.
Fermilab, Batavia, Illinois
Fermilab plans to boost the power of Main Injector beam to about 2 MW by building a new SC 8 GeV linac. Its H- beam will be strip injected and accumulated in upgraded Recycler ring, and then transferred to Main Injector for further acceleration to 120 GeV. Beam physics issues related to high intensity operation of Recycler ring and Main Injector are considered.
CERN, Geneva
BNL, Upton, Long Island, New York
In view of the CERN Proton Synchrotron replacement with a new ring (PS2), a detailed optics design is undertaken following several options, which cross or avoid transition. The different lattices are compared with respect to their linear optics flexibility, acceptance and chromatic properties. The effect of magnet misalignments in the beam orbit and linear optics functions are reviewed and correction schemes are proposed. Finally, the different lattice options are compared with respect to single particle non-linear dynamics.
CERN, Geneva
The construction of a Superconducting Proton Linac is planned at CERN during the next decade. It is foreseen to be constructed in two stages: a low duty cycle, low-power linac (LPSPL) as an injector for a new 50 GeV synchrotron (PS2) replacing the present PS, which could be upgraded to a high-duty cycle, high-power linac (HPSPL), for the needs of future facility(ies) requiring a multi-MW beam power. In this paper we present the criteria which were used to choose the frequency, gradient, and cryogenic temperature of the SPL. Since these questions are common to other proposed high-power proton linacs, we propose a generalization of the arguments. The various design options are discussed as well as their impact on beam dynamics, cavity performance, power consumption, cryogenics, overall efficiency, and cost of the facility.
Muons, Inc, Batavia
Fermilab, Batavia, Illinois
Muon colliders and neutrino factories impose demanding requirements on the proton accelerator systems that are used to produce the muons. Various concepts to meet those needs have been developed. A scheme that uses a powerful 8-GeV H- linac followed by storage rings for accumulation and bunch manipulations will be described and compared with other ideas.
RIKEN/RARF/CC, Saitama
RIKEN Nishina Center, Wako, Saitama
ANL, Argonne, Illinois
The accelerator complex for RIBF factory in RIKEN consists of the four ring cyclotrons with an injector linac. It can boost the energy of output beams from the linac up to 440 MeV/nucleon for light ions and 350 MeV/nucleon for very heavy ions. The first beam from the accelerator complex was successfully extracted at the end of 2006. An 28GHz SC-ECR ion source will be installed at the front end of the injector linac on a 100kV HV platform to increase the beam intensity of very heavy ions such as uranium. Beam dynamics from the ion source to the exit of the injector were simulated using TRACK. How much space charge forces affect on beam qualities in the successive ring cyclotrons will be discussed.
KAERI, Daejon
The main purposes of the proton engineering frontier project (PEFP) are developing 100-MeV proton linac and supplying 20-MeV and 100-MeV proton beams to user group. The 20-MeV part of the linac with 24% beam duty has been successfully installed and tested at the KAERI site. Now we are supplying 20-MeV proton beams to users in a restricted beam condition. The fabrication of the remaining part of the DTL with the beam duty of 8% is in progress. The PEFP user facility includes 5 beam lines for 20-MeV and 100-MeV beams, respectively. Form the user surveys the purposes and beam specs are determined for the beam lines. The characteristics of the PEFP beam supplying systems are using the AC magnets to periodically distribute proton beams into several beam lines. At the same time, PEFP concentrates on developing the potential user group of the high intensity proton beams. Several beam utilization programs are under way for this purpose. The civil construction is scheduled to start at the end of this year. The present status and progress of the project are summarized in detail.
LANL, Los Alamos, New Mexico
We are developing a compact deuteron-beam accelerator up to the energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IH-PMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.
Fermilab, Batavia, Illinois
The High Intensity Neutrino Source (HINS) program at Fermilab will demonstrate new technologies suitable for the low-energy front-end of a high intensity H- linac based on independently phased superconducting resonators (driven by a single power source). Eighteen β. = 0.21 superconducting single spoke resonators, operating at 325 MHz with an nominal accelerating field of 10 MV/m, comprise the first stage of the linac cold section. For two prototype resonators, we report on the construction phases and the comparison of low gradient RF measurements with calculations. After Buffered Chemical Polishing and High Pressure Rinse at Argonne, one resonator has undergone high gradient RF testing at 2.0° 4.5°Kelvin in the Vertical Test Stand (VTS) at Fermilab. We present measurements from the VTS tests, including BCS resistance and the quality factor as a function of accelerating field. In order to help understand multipacting and field emission, RTD temperature sensors were mounted on the exterior walls of the cavity, and x-ray sensing diodes were mounted near the cavity in the liquid helium bath. The resonator reached an accelerating field of 13.4 MV/m.
STFC/RAL/ISIS, Chilton, Didcot, Oxon
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
ISIS is the world’s most productive spallation neutron source, at the Rutherford Appleton Laboratory in the UK. Presently, it runs at beam powers of 0.2 MW, with upgrades in place to supply increased powers for the new Second Target Station due to start operation in 2008. This paper outlines favoured schemes for major upgrades to the facility in the megawatt regime, with options for 1, 2 and 5 MW. The ideas centre around new 3.2 GeV RCS designs that can be employed to increase the energy of the existing ISIS beam to provide powers of ~1 MW or, possibly as a second upgrade stage, accumulate and accelerate beam from a new 0.8 GeV linac for 2-5 MW beams. Summaries of ring designs are presented, along with studies and simulations to assess the key loss mechanisms that will impose intensity limitations. Important factors include injection, RF systems, instabilities, longitudinal and transverse space charge.
Soreq NRC, Yavne
ACCEL, Bergisch Gladbach
The Soreq Applied Research Accelerator Facility (SARAF) is built to be used for basic research, medical research, neutron based non-destructive testing and radio-pharmaceuticals development and production. The accelerator, designed and constructed by Accel Instruments GmbH, starts with a 5 mA, 20 keV/u ECR ion source. A LEBT transports the beam and matches it to a normal-conducting 4-rod RFQ. The RFQ bunches the beam at a frequency of 176 MHz 4 mA ions and accelerate the ions to 1.5 MeV/u. A 0.65 m long MEBT transports and matches the beam into the superconducting linac. The 20 m long linac is composed of six cryostats that contain a total of 44 half-wave resonators optimized for β0=0.09 and 0.15, which are kept at a temperature of 4.5 K by liquid helium. In order to achieve the dose rate criterion for hands-on maintenance, beam loss is limited to 1 nA/m. Extensive beam dynamics simulations, including error analysis with high statistics, indicate that beam loss will indeed be below the above mentioned criterion. Currently, Phase I of the SARAF linac, including the ion source, LEBT, RFQ, MEBT and the first SC cryostat, is installed on site and is undergoing commissioning.