BNL, Upton, Long Island, New York, USA
An alarm system is a vital component of any accelerator, as it provides a warning that some element of the system is not functioning properly. The severity and age of the alarm may sometimes signify whether urgent or deferred attention is required. For example, older alarms may inadvertently be given a lower priority if an assumption is made that someone else is already investigating it, whereas those that are more current may indicate the need for an immediate response. The alarm history also provides valuable information regarding the functionality of the overall system, thus careful tracking of these data is likely to improve response time and remove uncertainty about the current status. Since one goal of every alarm display is to be free of alarms, a clear and concise presentation of an alarm along with useful historic annotations can help the end user address the warning more quickly. By defining a discrete set of very specific alarm states and by utilizing database resources to maintain a complete and easily accessible alarm history, we anticipate a decrease in down time due to more efficient operator response and management of alarms.
BNL, Upton, Long Island, New York, USA
Among the accelerator projects under construction at the Relativistic Heavy Ion Collider (RHIC) is an R&D energy recovery LINAC (ERL) test facility. The ERL includes both a five-cell superconducting cavity as well as a superconducting, photoinjector electron gun. Because of the high-charge and high-current demands, effective higher-order mode (HOM) damping is essential, and several strategies are being pursued. Among these is the use of the fundamental power couplers as a means for damping some HOMs. Simulation studies have shown that the power couplers can play a substantial role in damping certain HOMs, and this presentation will discuss these studies along with measurements.
BNL, Upton, Long Island, New York, USA
Several future accelerator projects at the Relativistic Heavy Ion Collider are being developed using a super-conducting electron energy recovery LINAC along with a superconducting electron gun as the source. All of the projects involve high-current, high-charge operation and require effective higher-order mode (HOM) damping to achieve the performance objectives. Among the HOM designs being developed is a waveguide-type HOM load for the electron gun consisting of a ceramic break surrounded by ferrite tiles. This design is innovative in its approach and achieves a variety of ends including broadband HOM damping and protection of the superconducting cavity from potential damage to the ferrite tiles. Furthermore, the ceramic is an effective thermal transition. This design may be useful in various applications since it readily allows for replacement of the ferrite tiles with other materials and may also be useful for testing the absorbing properties of these materials. In this paper, the details of the design will be discussed along with current modelling and testing results as well as future plans.
BNL, Upton, Long Island, New York, USA
JLAB, Newport News, Virginia, USA
AES, Medford, NY, USA
The Brookhaven National Laboratory (BNL) 5-cell, 703 MHz superconducting RF accelerating cavity has been installed in the high-current energy recovery linac (ERL) experiment. This experiment will function as a proving ground for the development of high-current machines in general and is particularly targeted at beam development for an electron-ion collider (eRHIC). The cavity performed well in vertical tests, demonstrating gradients of 20 MV/m and a Q0 of 1010. Here we will present its performance in the horizontal tests, and discuss technical issues involved in its implementation in the ERL.
BNL, Upton, Long Island, New York, USA
The analysis of multi-layer beam tubes is a frequent problem and is usually solved with axially propagating waves. This treatment is ill suited to a short multi-layer structure such as the present example of a ferrite covered ceramic break in the beam tube at the ERL photo-cathode electron gun. This paper demonstrates that such structures can better be treated by radial wave propagation. The theoretical method is presented and numerical results are compared with measured network analyser data and Microwave Studio generated simulations. The results confirm the concept of radial transmission lines as a valid analytical method.
BNL, Upton, Long Island, New York, USA
BNL, Upton, Long Island, New York, USA
FRIB, East Lansing, Michigan, USA
MIT, Middleton, Massachusetts, USA
We present the design of future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 1034 cm-2 s-1 can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling and the compact magnets for recirculating passes. A natural staging scenario of step-by-step increases of the electron beam energy by builiding-up of eRHIC's SRF linacs and a potential of adding polarized positrons are also presented.
