Superconducting RF Cavity Frequency and Field Distribution Sensitivity Simulation
Frequency and electromagnetic field distribution sensitivity of a superconducting RF (SRF) cavity are the fundamental phyical paramethers in cavity and tuner design. At low temperature, the frequency sensitivity can be obtained by measuring prototype cavity, but it is not easy to test the filed distribution sensitivity. This paper presents and describes a simulation method combining ANSYS and SUPERFISH to calculate the cavity frequency and field distribution variation due to cavity’s small deformation caused by mechanical force, radiation force, thermal expansion etc.. As an example, the simulation results of the frequency and field flatness sensitivity on the SNS cavities were confirmed by their test results.
MECHANICAL ANALYSIS AND DESIGN OF THE PEFP LOW BETA CAVITY
The PEFP low beta superconducting RF cavity is the lowest beta elliptical cavity operating at pulse mode so far, the Lorentz force detuning control of the PEFP low beta cavity is a big challenge in cavity design. In this paper, a basic design consideration in the stiffening structure for Lorentz force detuning control has been presented. Based on this consideration, a new stiffening structure has been designed for the PEFP low beta cavity. The PEFP low beta cavity with this structure has low Lorentz force detuning coefficient KL, reasonable cavity field flatness sensitivity, frequency sensitivity, tuning sensitivity and stable mechanical property.
Fragment Rotational State Distributions From The Dissociation Of NeIBr: Experimental And Theoretical Results
The IBr fragment rotational state distributions that result when the NeIBr van der Waals molecule undergoes vibrational predissociation have been measured in a pump–probe laser‐induced fluorescence experiment. Independent of initial vibrational state and the number of quanta of vibrational energy lost from the I–Br coordinate, the rotational distributions extend over the full range of energetically accessible states. From the observation of energetic constraints on the rotational distribution, the dissociation energy (D0) is calculated to be 65.5±1.2 cm−1 for the A electronic state, v=16. For the X electronic state, v=0, D0=71.8±1.2 cm−1. Quantum mechanical bound state calculations carried out on a model A electronic state potential energy surface are in quantitative agreement with this result. The rotational distributions are broader than that predicted by either a Franck–Condon or classical impulsive model for the dissociation. The distributions are qualitatively in accord with classical trajectory calc...