Muons, Inc, Illinois, USA
ORNL, Oak Ridge, Tennessee, USA
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
ORNL RAD, Oak Ridge, Tennessee, USA
Tests were performed at SNS in collaboration with visiting colleagues from ISIS, UK to evaluate the uncesiated beam performance of the SNS RF H− ion sources. Two spare experimental sources, one with internal antenna and one with external antenna were used for the tests. The beam currents achieved with Cs-free operations accounted for about 1/3 to 1/2 of the beam currents produced with cesiated operations. ~17 mA uncesiated H− current was demonstrated within the tested RF power range up to 65 kW with the internal antenna source and ~15 mA with up to 40 kW RF with the external antenna source. In Cs-free operations, the power supply for the electron dumping electrode was loaded down below its set voltage but was not too drastic to tamper the operation.
ORNL RAD, Oak Ridge, Tennessee, USA
The Spallation Neutron Source (SNS) extraction kicker 60Hz pulsed system uses 14 Blumlein pulse-forming network (PFN) modulators that require timing synchronization with stable rise times. A replacement design has been investigated and the kickers have been converted over to use a solid-state switch design, eliminating the lifetime and stability issues associated with thyratrons and subsequent maintenance costs. All kickers have been converted, preventing thyratron jitter from impacting the beam performance and allowing higher-precision target impact. This paper discusses the completion of the conversion of the high-voltage switch from a thyratron to a solid-state switch with improved stability of the extraction system and associated accelerator beam stability.
LANL, Los Alamos, New Mexico, USA
An 800 MeV 100 µA proton beam is delivered to the Lujan Center, one of five user facilities at the LANSCE linear accelerator center, to generate an intense beam of pulsed neutrons. The Lujan Center beam transport line, known as 1L beamline, is over 68 meters in length, starting from the ROWS01. The beamline is consisted with bending and focusing elements before it reaches the end of the 1L beam optics system, where the beam spot size is nominally 1.5 cm (RMS). The Mark IV target assembly has been designed to optimize the neutron production for the 1L target in the Lujan center to improve the flux and resolution. As part of the safety review of this design, it becomes necessary to know the beam intensity and size on the new target. Using the new measurements of the beamline, calculated beam sizes using the LANL version of the beam envelope code TRANSPORT and CERN code MAD-X are compared. The input beam parameters for the codes were extracted from ORBIT analysis of the proton storage ring beam. Beam envelope measurements were made at various locations throughout the beamline using wire scanners. The predicted beam envelopes and measured data agree within expected errors.
*LA-UR-19-22889
FRIB, East Lansing, Michigan, USA
NSCL, East Lansing, Michigan, USA
MSU, East Lansing, Michigan, USA
BINP SB RAS, Novosibirsk, Russia
Facility for Rare Isotope Beams (FRIB) is a next-generation rare-isotope research facility under construction at Michigan State University (MSU). FRIB will produce rare-isotope beams of unprecedented intensities by impinging a 400 kW heavy-ion beam on a production target and by collecting and purifying the rare isotopes of interest with a fragment separator. A thermal imaging system (TIS) has been developed to monitor the beam spot on the production target. The main features and characteristics of optical system is presented. The prototype of optical system has been tested.
FRIB, East Lansing, Michigan, USA
Facilities for rare isotope beams provide tools for nuclear science research and tools for applications ranging from fundamental nuclear structure and dynamics to societal benefits in medicine, energy, material sciences and national security. State-of-the-art rare isotope facilities can be based on an isotope separation on-line (ISOL) approach using mostly high-power proton beams striking a thick target where the isotopes are produced in the target, or an in-flight fragment separation (IF) approach using high-power heavy ion beams striking upon a thinner target where the isotopes continue out of the target followed by fragment separation. This tutorial class introduces high power hadron accelerators as driver machines for rare isotope production, summarizing the key design philosophy, physical and technical challenges, and current world-wide development status. As an example, the Facility for Rare Isotope Beams (FRIB) project is used to illustrate the process of establishing such facilities.
