Conceptual Design of Rapid Circular Particle Accelerator Using High-Gradient Resonant Cavities with Fixed Frequency

A new high-energy particle accelerator with static combined type of magnetic field and high-gradient resonant cavities is introduced for muon acceleration up to 300 MeV and proton acceleration up to 400 MeV. The accelerator concept is expected to realize Mpps-class rapid cycling high-energy particle acceleration in circular particle accelerators. Conceptual designs of the circular accelerator are discussed with an emphasis on short lifetime particles. The fundamental concept of particle acceleration and the related practical issues, which should be discussed when designing the accelerators, are described as well

Lattice Design Of Jhf Synchrotrons

Several kinds of lattice structures have been designed and examined for the JHF synchrotorons. The high(or imaginary) fl t lattice has been used as the 50 GeV main ring to avoid beam loss at the transition crossing. We have studied the feasibility to apply this scheme to the 3 GeV booster as a flexible momentum compaction lattice. These rings have wide tunablilities and flexibilities of the linear optics. The possibility of increasing the extraction energy of the booster to 6 GeV has been investigated. 1 INTRODUCTION The Japan Hadron Facility(JHF) consists of the 50 GeV main ring, the 3 GeV booster and the 200 MeV linac. Because the beam intensity of the main ring is extremely high (2\Theta10 14 ppp), a low beam loss is required. In order to avoid beam loss at the transition crossing, we have employed the imaginary fl t lattice which does not have a transition energy. The 3 GeV booster is a rapid cycle synchrotron of which repetition rate is 25 Hz. It will be constructed in the ex..

Technical Note : Range verification of pulsed proton beams from fixed-field alternating gradient accelerator by means of time-of-flight measurement of ionoacoustic waves

Purpose: Ionoacoustics is one of the promising approaches to verify the beam range in proton therapy. However, the weakness of the wave signal remains a main hindrance to its application in clinics. Here we studied the potential use of a fixed-field alternating gradient accelerator (FFA), one of the accelerator candidates for future proton therapy. For such end, magnitude of the pressure wave and range accuracy achieved by the short-pulsed beam of FFA were assessed, using both simulation and experimental procedure. Methods: A 100 MeV proton beam from the FFA was applied on a water phantom, through the acrylic wall. The beam range measured by the Bragg peak (BP)-ionization chamber (BPC) was 77.6 mm, while the maximum dose at BP was estimated to be 0.35 Gy/pulse. A hydrophone was placed 20 mm downstream of the BP, and signals were amplified and stored by a digital oscilloscope, averaged, and low-pass filtered. Time-of-flight (TOF) and two relative TOF values were analyzed in order to determine the beam range. Furthermore, an acoustic wave transport simulation was conducted to estimate the amplitude of the pressure waves. Results: The range calculated when using two relative TOF was 78.16 +/- 0.01 and 78.14 +/- 0.01 mm, respectively, both values being coherent with the range measured by the BPC (the difference was 0.5-0.6 mm). In contrast, utilizing the direct TOF resulted in a range error of 1.8 mm. Fivefold and 50-fold averaging were required to suppress the range variation to below 1 mm for TOF and relative TOF measures, respectively. The simulation suggested the magnitude of pressure wave at the detector exceeded 7 Pascal. Conclusion: A submillimeter range accuracy was attained with a pulsed beam of about 21 ns from an FFA, at a clinical energy using relative TOF. To precisely quantify the range with a single TOF measurement, subsequent improvement in the measuring system is required