54598069
MODELLING OF THE EMMA ns-FFAG RING USING GPT
EMMA (Electron Machine with Many Applications) is a prototype non-scaling Fixed-Field Alternating Gradient (ns-FFAG) accelerator whose construction at Daresbury Laboratory, UK, was completed in the autumn of 2010. The energy recovery linac ALICE [1] will serve as an injector for EMMA, within an energy range of 10 to 20 MeV. The injection line consists of a symmetric 30 dogleg to extract the beam from ALICE, a matching section and a tomography section for transverse emittance measurements. This is followed by a transport section to the injection point of the EMMA ring. The ring is composed of 42 cells, each containing one focusing and one defocusing quadrupole. Commissioning of the EMMA ring started in late 2010. A number of different injection energy and bunch charge configurations are planned; for some the effects of spacecharge may be significant. It is therefore necessary to model the electron beam transport in the injection line and ring using a code capable of both calculating the effect of and compensating for space-charge. Therefore the General Particle Tracer (GPT) code [2] has been used. A range of injection beam parameters have been modelled for comparison with experimental results.
117112415
A NEW CONTINUOUS MUON BEAM LINE USING A HIGHLY EFFICIENT PION CAPTURE SYSTEM AT RCNP
A new muon source with continuous time structure is under construction at Research Center of Nuclear Physics (RCNP), Osaka University. The ring cyclotron of RCNP can provide 400W 400MeV proton beam. Using this proton beam, the MuSIC produces a high intense muon beam. The target muon intensity is 10 8 muons/second, which is achieved by a pion capture with great efficiency to collect pions and muons using a solenoidal magnetic field. A pion production target system is located in a 3.5 Tesla solenoidal magnetic field generated by a super-conducting solenoid magnet. The proton beam hits the target, and backward pions and muons are captured by the field. Then they are transported by a curved solenoid beam line to experimental apparatus.The construction has been started in 2010, and would be finished in 5 years. We plan to carry out not only an experiment to search the lepton flavor violating process but also other experiments for muon science and their applications using the intense muon beam.
119530771
Acceleration in the linear non-scaling fixed-field alternating-gradient accelerator EMMA
In a fixed-field alternating-gradient (FFAG) accelerator, eliminating pulsed magnet operation permits rapid acceleration to synchrotron energies, but with a much higher beam-pulse repetition rate. Conceived in the 1950s, FFAGs are enjoying renewed interest, fuelled by the need to rapidly accelerate unstable muons for future high-energy physics colliders. Until now a ‘scaling’ principle has been applied to avoid beam blow-up and loss. Removing this restriction produces a new breed of FFAG, a non-scaling variant, allowing powerful advances in machine characteristics. We report on the first non-scaling FFAG, in which orbits are compacted to within 10 mm in radius over an electron momentum range of 12–18 MeV/c. In this strictly linear-gradient FFAG, unstable beam regions are crossed, but acceleration via a novel serpentine channel is so rapid that no significant beam disruption is observed. This result has significant implications for future particle accelerators, particularly muon and high-intensity proton accelerators.
122581027
Mobile Telescope for Examining Vertical Intensity of Cosmic Ray Fluxes
This report describes the mechanical and electrical features of a mobile fluorescer‐photomultiplier cosmic ray telescope. The telescope has been used on frequent occasions to obtain cosmic ray equator points and to examine the vertical cosmic ray intensity at atmospheric depths of 200 to 250 g/cm2. Statistical errors in the total counting rates were less than 1% and over‐all experimental errors totaled less than 2%.
116493819
A TELESCOPE FOR EXAMINING THE VERTICAL INTENSITY OF COSMIC RAY FLUXES ON A WORLD-WIDE BASIS.