Fermilab, Batavia, USA
Fermilab is planning the construction of a prototype front end of the Project X linac. The Project X Injector Experiment (PXIE) is expected to accelerate 1 mA cw H− beam up to 30 MeV. Some of the major goals of the project are to test a cw RFQ and H− source, a broadband bunch-by-bunch beam chopper and a low-energy superconducting linac. The successful characterization and operation of such an accelerator places stringent requirements on beam line diagnostics. These crucial beam measurements include bunch currents, beam orbit, beam phase, bunch length, transverse profile and emittance, beam halo and tails, as well as the extinction performance of the broadband chopper. This paper presents PXIE beam measurement requirements and instrumentation development plans. Also presented are plans to test many of these instruments at the Fermilab High Intensity Neutrino Source (HINS) beam facility. Since HINS is already an operational accelerator, utilizing HINS for instrumentation testing allows for quicker development of the required PXIE diagnostics.
Fermilab, Batavia, USA
Fermilab’s Recycler ring was used as a storage ring for accumulation and subsequent manipulations of 8 GeV antiprotons destined for the Tevatron collider. To satisfy these missions, a unique electron cooling system was designed, developed and successfully implemented. The most important features that distinguish the Recycler cooler from other existing electron coolers are its relativistic energy (it employs a 4.3 MeV, 0.1 A DC electron beam), a weak continuous longitudinal magnetic field in the cooling section (~100 G), and lumped focusing elsewhere. With the termination of the collider operation at Fermilab, the cooler operation was also terminated. In this article, we will summarize the experience of commissioning, optimizing and running this unique machine over the 6 years of its existence.
Fermilab, Batavia, USA
The Project X Injector Experiment (PXIE) will be a prototype of the Project X front end that will be used to validate the design concept and decrease technical risks. One of the most challenging components of PXIE is the wide-band chopping system of the Medium Energy Beam Transport (MEBT) section, which will form an arbitrary bunch pattern from the initially CW 162.5 MHz 5mA beam. The present scenario assumes diverting 80% of the beam to an absorber to provide a beam with the average current of 1mA to SRF linac. This absorber must withstand a high level of energy deposition and high ion fluence, while being positioned in proximity of the superconductive cavities. This paper discusses design considerations for the absorber, including specific challenges as spreading of energy deposition, management of temperatures and temperature-induced mechanical stresses, radiation effects, surface effects (sputtering and blistering), and maintaining vacuum quality. Thermal and mechanical analyses of a conceptual design are presented, and future plans for the fabrication and testing of a prototype are described.
Fermilab, Batavia, USA
SLAC, Menlo Park, California, USA
A capability to provide a large variety of bunch patterns is crucial for the concept of the Project X serving MW-range beam to several experiments simultaneously. This capability will be realized by the Medium Energy Beam Transport’s (MEBT) chopping system that will divert 80% of all bunches of the initially 5mA, 2.1 MeV CW 162.5 MHz beam to an absorber according to a pre-programmed bunch-by-bunch selection. Being considered one of the most challenging components, the chopping system will be tested at the Project X Injector Experiment (PXIE) facility that will be built at Fermilab as a prototype of the Project X front end. The bunch deflection will be made by two identical sets of travelling-wave kickers working in sync. Presently, two versions of the kickers are being investigated: a helical 200 Ω structure with a switching-type 500 V driver and a planar 50 Ω structure with a linear ±250 V amplifier. This paper will describe the chopping system scheme and functional specifications for the kickers, present results of electromagnetic measurements of the models, discuss possible driver schemes, and show a conceptual mechanical design.
Fermilab, Batavia, USA
Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Fermilab, Batavia, USA
LBNL, Berkeley, California, USA
ANL, Argonne, USA
LBNL, Berkeley, California, USA
Fermilab, Batavia, USA
IAP, Frankfurt am Main, Germany
A multi-MW proton facility, Project X has been proposed and is currently under development at Fermilab. Project X is a key accelerator complex for intensity frontier of future high energy physics programs in the US. In collaboration with Fermilab, LBNL takes the responsibility in the development and design studies of the front-end system for Project X. The front-end system would consist of H− ion source(s), low-energy beam transport (LEBT), 162.5 MHz normal conducting CW Radio-Frequency-Quadrupole (RFQ) accelerator, medium-energy beam transport (MEBT), and beam chopper(s). In this paper, we will review and present recent progress of the front-end system studies, which will include the RFQ beam dynamics design, RF structure design, thermal and mechanical analyses and fabrication plan, LEBT simulation studies and concept for LEBT chopper.