Dynamics. Differential Algebraic Techniques. Fields. Maps: Calculation. Maps: Properties. Spectrometers. Repetitive Systems.

Modern map methods in particle beam physics

We have developed a method for achieving excellent resolving power in in-flight particle identification of radioactive isotope (RI) beams at the BigRIPS fragment separator at the RIKEN Nishina Center RI Beam Factory (RIBF). In the BigRIPS separator, RI beams are identified by their atomic number Z and mass-to-charge ratio A/Q which are deduced from the measurements of time of flight (TOF), magnetic rigidity (Bρ) and energy loss (ΔE), and delivered as tagged RI beams to a variety of experiments including secondary reaction measurements. High A/Q resolution is an essential requirement for this scheme, because the charge state Q of RI beams has to be identified at RIBF energies such as 200–300 MeV/nucleon. By precisely determining the Bρ and TOF values, we have achieved relative A/Q resolution as good as 0.034% (root-mean-square value). The achieved A/Q resolution is high enough to clearly identify the charge state Q in the Z versus A/Q particle identification plot, where fully-stripped and hydrogen-like peaks are very closely located. The precise Bρ determination is achieved by refined particle trajectory reconstruction, while a slew correction is performed to precisely determine the TOF value. Furthermore background events are thoroughly removed to improve reliability of the particle identification. In the present paper we present the details of the particle identification scheme in the BigRIPS separator. The isotope separation in the BigRIPS separator is also briefly introduced.

Identification and separation of radioactive isotope beams by the BigRIPS separator at the RIKEN RI Beam Factory

The QMG/2, a magnetic spectrograph for nuclear research☆

The QDMDQ magnetic spectrograph “Raiden” (I)-design and construction

Second order transfer matrices of real magnetic and electrostatic sector fields

The first‐ and second‐order matrix equations for the magnetic optics of the midplane of uniform‐field wedge magnets have been derived. The calculations include rotated input and output wedges and curved surfaces on the input and output faces. A second‐order matrix algebra has been developed to handle beam transport optics for multiple element systems in a manner similar to that which has been used in the past for the first‐order beam transport optics.

R. Belbeoch

Papers

First‐ and Second‐Order Magnetic Optics Matrix Equations for the Midplane of Uniform‐Field Wedge Magnets

Sur la modification des propriétés des aimants produite par les effets de bord. Cas des aimants à champ uniforme et à gradient de champ