scholarly journals Closed orbit feedback system for the fast ramping hadron synchrotrons

2021 ◽  
Author(s):  
◽  
Sajjad Hussain Mirza
Keyword(s):  
Disturbance Rejection ◽  
Closed Orbit ◽  
Feedback System ◽  
Beam Position ◽  
Orbit Correction ◽  
Hardware Resource ◽  
Beam Parameters ◽  
The Stability ◽  
Orbit Response Matrix ◽  
Beam Position Monitors

The realization of a fast and robust closed orbit feedback (COFB) system for the on-ramp orbit correction at SIS18 synchrotron of FAIR project is reported in this thesis. SIS18 has some peculiar behaviors including on-ramp optics variation, very short lengths of the ramps (200 ms to 1 s) and a cycle-to-cycle variation of beam parameters. The realized fast COFB system being robust against above mentioned features of SIS18 is a first of its kind and the course to its realization led to some novel contributions in the field of closed orbit correction. A new method relying on the discrete Fourier transform (DFT)-based decomposition of the orbit response matrix (ORM) has been introduced, exploiting the symmetry in the arrangement of beam position monitors (BPMs) and the corrector magnets in the synchrotrons. A nearest-circulant approximation has also been introduced for synchrotrons having slight deviation from the symmetry, making the method applicable to a vast majority of synchrotrons. Moreover, the performance and the stability analysis of COFB systems in the presence of ORM mismatch between the synchrotron and the feedback controller is presented. The COFB systems are divided into slow and fast regimes and a new stability criterion consistent with measurements, is introduced. The practicality of the criterion is verified experimentally at COSY Jülich and is used for the analysis of various sources of ORM mismatch at SIS18. The commissioning of the SIS18 COFB system is also reported in detail which relies on Libera Hadron as the main hardware resource for the controller implementation. The on-ramp orbit correction is demonstrated for the horizontal plane of SIS18, for the disturbance rejection up to 600 Hz.

New beam-position monitor system for upgraded Photon Factory storage ring

1998 ◽  
Vol 5 (3) ◽  
pp. 624-626 ◽  
Author(s):  
K. Haga ◽  
T. Honda ◽  
M. Tadano ◽  
T. Obina ◽  
T. Kasuga
Keyword(s):  
Storage Ring ◽  
Closed Orbit ◽  
Processing System ◽  
Feedback System ◽  
Beam Position Monitor ◽  
Signal Processing System ◽  
Beam Position ◽  
Photon Factory ◽  
Beam Movement ◽  
Improve Reliability

Accompanying the brilliance-upgrading project at the Photon Factory storage ring, the beam-position monitor (BPM) system has been renovated. The new system was designed to enable precise and fast measurements to correct the closed-orbit distortion (COD), as well as to feed back the orbit position during user runs. There are 42 BPMs newly installed, amounting to a total of 65 BPMs. All of the BPMs are calibrated on the test bench using a coaxially strung metallic wire. The measured electrical offsets are typically 200 µm in both directions, which is 1/2–1/3 of those of the old-type BPMs. In the signal-processing system, PIN diode switches are employed in order to improve reliability. In the fastest mode, this system is capable of measuring COD within about 10 ms; this fast acquisition will allow fast suppression of the beam movement for frequencies up to 50 Hz using a global feedback system.

Mechanical requirement and influence on the design and manufacturing of beam position monitor of Taiwan photon source

2011 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
H. P. Hsueh ◽  
I. T. Huang ◽  
C. C. Chang ◽  
S. N. Hsu ◽  
G. Y. Hsiung ◽  
...  
Keyword(s):  
Feedback System ◽  
Time Domain Reflectometry ◽  
Beam Position ◽  
Stanford Linear Accelerator ◽  
Lack Of Control ◽  
Design And Manufacturing ◽  
Stanford Linear Accelerator Center ◽  
Beam Orbit ◽  
Photon Source ◽  
Beam Position Monitors

The beam position monitors (BPMs) with submicron-level resolution act as the major eyes of storage ring in detecting the position of electron beams and are used for feedback system to guide the beam orbit to the desired track. Compared to major improvements on backend electronics, the physical devices generate and transmit signals had little improvement due to the lack of control on manufacturing processes including all mechanical tolerance requirements. The design started with ANSYS to simulate mechanical deformation. Due to the small size (submillimetre) and complicated assembly of feedthrough structure, it is difficult to achieve 1 % tolerance (submicron) in all aspects including machining and brazing. The smallest tolerance for machining is 5 µ and the overall tolerance will be 30 µm. The influence of the tolerance on mechanical will be shown on time-domain reflectometry measurement. The resulted heat-related issue will also be discussed and addressed since the problem happened at SLAC (private communication with Albert Sheng at Stanford Linear Accelerator Center) and DIAMOND (presented at the RF Button Heating Mini-Workshop at EPAC 2008). Manufacturing steps will be described. The consequence of mismatch on manufacturing will be discussed. All related measurement and simulation data are presented in this paper.

Nematicons routing through two types of disclination lines in chiral nematic liquid crystals

2014 ◽  
Vol 23 (04) ◽  
pp. 1450042 ◽  
Author(s):  
Michał Kwaśny ◽  
Urszula A. Laudyn ◽  
Katarzyna A. Rutkowska ◽  
Mirosław A. Karpierz
Keyword(s):  
Liquid Crystals ◽  
Wave Vector ◽  
Nematic Liquid Crystals ◽  
Input Beam ◽  
Oriented Sample ◽  
Beam Position ◽  
Chiral Nematic ◽  
Different Types ◽  
Optimal Beam ◽  
Beam Parameters

In this work, we study nematicons propagation at the disclination lines in a wedge-shaped planarly oriented sample. Using optimal beam parameters for light self-trapping and varying the input beam position and direction of the wave vector k with respect to the z-axis, we gain insight in the nematicons propagation in the highly disturbed area around two different types of disclination lines in chiral nematic.

Beam position monitors

1988 ◽  
Vol 1 (3) ◽  
pp. 27-31 ◽  
Author(s):  
A. Gaupp ◽  
F. P. Wolf
Keyword(s):  
Beam Position ◽  
Beam Position Monitors

Design of Electrostatic Precipitator Power System Based on Auto Disturbance Rejection Controller

2013 ◽  
Vol 846-847 ◽  
pp. 190-194
Author(s):  
Shu Jun Yin ◽  
Xue Ren Li ◽  
Ji Geng Luo
Keyword(s):  
Power Supply ◽  
Disturbance Rejection ◽  
Power Supply System ◽  
Electrostatic Precipitator ◽  
Supply System ◽  
System Stability ◽  
Engineering Practice ◽  
Single Chip ◽  
High Voltage Power Supply ◽  
The Stability

The paper designs a three-phase high voltage power supply system based on active disturbance rejection controller which make single-chip microcomputer ATmega128 as the main control chip and the system improve the stability and control precision of dust removing power. Engineering practice shows that, the DC power supply system has the advantages of convenient operation, high work efficiency, system stability.

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