Design and beam dynamics of CEPC damping ring system

2021 ◽  
pp. 2142006
Author(s):  
Dou Wang ◽  
Xiaohao Cui ◽  
Cai Meng ◽  
Daheng Ji ◽  
Yudong Liu ◽  
...  
Keyword(s):  
Positron Beam ◽  
Ring System ◽  
Beam Dynamics ◽  
Parameter Choice ◽  
Beam Loss ◽  
Transverse Emittance ◽  
Instability Effect

A damping ring system which includes a small 1.1 GeV ring and two transport lines is introduced in CEPC linac in order to reduce the transverse emittance of positron beam at the end of linac and hence reduce the beam loss in the booster. This paper introduces the parameter choice and optics study of damping ring. The corresponding instability effect and IBS effect are also checked to make sure the design current and design emittance can be realized. Except for damping ring, two transport lines are needed to match the parameters between linac and damping ring. Both designs for energy compressor and bunch compressor including beam simulations are discussed in this paper.

scholarly journals Longitudinal Beam Dynamics for the Heavy-Ion Synchrotron Booster Ring at HIAF

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
D. Y. Yin ◽  
J. Liu ◽  
G. D. Shen ◽  
H. Du ◽  
J. C. Yang ◽  
...  
Keyword(s):  
High Intensity ◽  
Heavy Ion ◽  
High Energy ◽  
Beam Dynamics ◽  
Bunch Length ◽  
Voltage Amplitude ◽  
Energy Fluctuation ◽  
Beam Emittance ◽  
Beam Loss ◽  
Injection Energy

To accelerate high-intensity heavy-ion beams to high energy in the booster ring (BRing) at the High-Intensity Heavy-Ion Accelerator Facility (HIAF) project, we take the typical reference particle 238U35+, which can be accelerated from an injection energy of 17 MeV/u to the maximal extraction energy of 830 MeV/u, as an example to study the basic processes of longitudinal beam dynamics, including beam capture, acceleration, and bunch merging. The voltage amplitude, the synchronous phase, and the frequency program of the RF system during the operational cycle were given, and the beam properties such as bunch length, momentum spread, longitudinal beam emittance, and beam loss were derived, firstly. Then, the beam properties under different voltage amplitude and synchronous phase errors were also studied, and the results were compared with the cases without any errors. Next, the beam properties with the injection energy fluctuation were also studied. The tolerances of the RF errors and injection energy fluctuation were dictated based on the CISP simulations. Finally, the effect of space charge at the low injection energy with different beam intensities on longitudinal emittance and beam loss was evaluated.

SPPC/CEPC lattice design and beam dynamics study

2017 ◽  
Vol 32 (34) ◽  
pp. 1746005 ◽  
Author(s):  
Feng Su ◽  
Jie Gao ◽  
Yukai Chen ◽  
Jingyu Tang ◽  
Yiwei Wang ◽  
...  
Keyword(s):  
Beam Dynamics ◽  
Parameter Choice ◽  
Proton Proton ◽  
Double Ring ◽  
Lattice Design ◽  
Dynamic Aperture

In this paper, we introduced the parameter choice and the first version lattice design for a 61 km and 100-km Super Proton–Proton Collider (SPPC). We started the lattice design and the beam dynamics study from last year and showed the preliminary dynamic aperture result of these two SPPC lattice versions. We also showed the layout, the lattice design and the dynamic aperture study of a CEPC partial double ring, an advanced partial double ring and a fully partial double ring schemes.

R&D of CEPC injector linac

2021 ◽  
pp. 2142013
Author(s):  
Jingru Zhang ◽  
Cai Meng ◽  
Dazhang Li ◽  
Dou Wang ◽  
Guoxi Pei ◽  
...  
Keyword(s):  
Band Structure ◽  
Positron Beam ◽  
Rf System ◽  
Baseline Design ◽  
Pulse Compressor ◽  
Transverse Emittance ◽  
Key Technologies ◽  
Main Ring ◽  
Cavity Design

The CEPC includes a main ring and an injector. The injector consists of a booster and a linac. In order to meet the requirements of the booster, the baseline design of the linac is a 10 GeV electron and positron linac. Two alternative linac designs have also been introduced in this paper. For the linac baseline design, one-bunch-per-pulse is adopted. A 1.1 GeV damping ring is used to reduce the transverse emittance of positron beam. The main RF system of the linac adopts normal conducting S-band structure. Some key technologies of linac are development. The S-band structure and pulse compressor have been researched and studied. In the damping ring, two cavities used to provide 2 MV voltage. The preliminary cavity design has finished.

INVESTIGATION AND OPTIMIZATION OF LOW-ENERGY HEAVY-ION BEAM DYNAMICS IN PERIODIC AXISYMMETRICAL STRUCTURES WITH DC FOCUSING

2009 ◽  
Vol 24 (05) ◽  
pp. 843-856 ◽  
Author(s):  
VYACHESLAV SERGEEVICH DYUBKOV ◽  
EDUARD SERGEEVICH MASUNOV
Keyword(s):  
Ion Beam ◽  
Heavy Ion ◽  
Low Energy ◽  
Beam Dynamics ◽  
Smooth Approximation ◽  
Parameter Choice ◽  
Energy Beam ◽  
Beam Focusing ◽  
Spatially Periodic ◽  
Dynamics Stability

It is well-known that nonsynchronous harmonics of a RF field can focus particles. In order to focus ultra-low energy beam particles, a spatially periodic electrostatic field can be used, too. In this case the transverse focusing is provided by a periodic array of electrostatic lenses. This article is dedicated to questions of two high-current low-energy beam focusing types used in an injector-buncher of an ion linear accelerator, an application of a spatially periodic electrostatic focusing being examined for the first time. A two-dimensional nonlinear motion equation is derived in the Hamiltonian form in a smooth approximation. It allows us to study a correlation between the longitudinal and transverse ion beam dynamics at low energies. An investigation of the phase and transverse beam dynamics stability conditions in the initial part of the linac are given consideration. Conditions of the beam dynamics stability are found and analyzed. An approach to the field optimization problem is described. A method of the geometric parameter choice is worked out for a realization of the required field distributions in each structure. To verify the results of the beam dynamics stability analysis and optimized structure parameter choice, numerical simulations of low-energy heavy-ion beams are carried out.

Stochasting modeling of planetary ring systems

1984 ◽  
Vol 75 ◽  
pp. 461-469 ◽  
Author(s):  
Robert W. Hart
Keyword(s):  
Maximum Entropy ◽  
Ring System ◽  
The Sun ◽  
Ultimate State ◽  
Interparticle Interactions ◽  
Ring Systems ◽  
First Order ◽  
Planetary Ring ◽  
Insight Into

ABSTRACTThis paper models maximum entropy configurations of idealized gravitational ring systems. Such configurations are of interest because systems generally evolve toward an ultimate state of maximum randomness. For simplicity, attention is confined to ultimate states for which interparticle interactions are no longer of first order importance. The planets, in their orbits about the sun, are one example of such a ring system. The extent to which the present approximation yields insight into ring systems such as Saturn's is explored briefly.

Effectiveness of Brushing Associated with Oral Irrigation in Maintenance of Peri-Implant Tissues and Overdentures: Clinical Parameters and Patient Satisfaction.

2020 ◽  
Author(s):  
Marcela Moreira Salles ◽  
Viviane de Cássia Oliveira ◽  
Ana Paula Macedo ◽  
Claudia Helena Silva-Lovato ◽  
Helena de Freitas Oliveira Paranhos
Keyword(s):  
Patient Satisfaction ◽  
Analogue Scale ◽  
Ring System ◽  
Complete Dentures ◽  
Gingival Index ◽  
Prosthetic Rehabilitation ◽  
Mean Values ◽  
Probing Depth ◽  
Significant Difference ◽  
High Level

Implant-supported prostheses hygiene and peri-implant tissues health are considered to be predictive factors for successful prosthetic rehabilitation. Therefore, the purpose of this study was to evaluate the effectiveness of brushing associated with oral irrigation measured as biofilm-removing capacity, maintenance of healthy oral tissues, and patient satisfaction. A randomized, crossover clinical trial was conducted with 38 patients who wore conventional maxillary complete dentures and mandibular overdentures retained by the O-ring system. The patients were instructed to use the following hygiene methods for 14 days: mechanical brushing [MB (brush and dentifrice - Control)]; and MB with oral irrigation [WP (Waterpik - Experimental)]. Biofilm-removing capacity and maintenance of healthy oral tissues were evaluated by the Modified Plaque Index (PI), Gingival Index (GI), Probing Depth (PD), and Bleeding on Probing Index (BP) recorded at baseline and after each method. In parallel, patients answered a specific questionnaire using a Visual Analogue Scale after each hygiene method. Data were analyzed by Friedman and Wilcoxon tests (α=0.05). The results showed significantly lower PI, GI, PD, and BP indices after application of the hygiene methods (P<0.001) than those observed at baseline. However, no significant difference was found between MB and WP. The satisfaction questionnaire responses to both methods showed high mean values for all questions, with no statistically significant difference found between the answers given after the use of MB and WP (P>0.05). The findings suggest that WP was effective in reducing PI, GI, PD, and BP indices and provided a high level of patient satisfaction.

Synthesis of Spongidine A, D and Petrosaspongiolide L Methyl Ester Using Pyridine C-H Functionalization

2019 ◽  
Author(s):  
Florian Bartels ◽  
Manuela Weber ◽  
Mathias Christmann
Keyword(s):  
Natural Products ◽  
Methyl Ester ◽  
Hydrogen Atom ◽  
Phospholipase A2 ◽  
Late Stage ◽  
Hydrogen Atom Transfer ◽  
Ring System ◽  
Tetracyclic Core ◽  
Intramolecular Hydrogen ◽  
Phospholipase A2 Inhibitors

<div>An efficient strategy for the synthesis of the potent phospholipase A2 inhibitors spongidine A and D is presented. The tetracyclic core of the natural products was assembled via an intramolecular hydrogen atom transfer‐initiated Minisci reaction. A divergent late‐stage functionalization of the tetracyclic ring system was also used to achieve a concise synthesis of petrosaspongiolide L methyl ester.</div>

Tele-Substitution Reactions in the Synthesis of a Promising Class of Antimalarials

2020 ◽  
Author(s):  
Marat Korsik ◽  
Edwin Tse ◽  
David Smith ◽  
William Lewis ◽  
Peter J. Rutledge ◽  
...  
Keyword(s):  
Heterocyclic Ring ◽  
Ring System ◽  
Substitution Reactions ◽  
Laboratory Notebook ◽  
Polar Solvents ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Core ◽  
Nmr Data

<p></p><p>We have discovered and studied a <i>tele</i>substitution reaction in a biologically important heterocyclic ring system. Conditions that favour the <i>tele</i>-substitution pathway were identified: the use of increased equivalents of the nucleophile or decreased equivalents of base, or the use of softer nucleophiles, less polar solvents and larger halogens on the electrophile. Using results from X-ray crystallography and isotope labelling experiments a mechanism for this unusual transformation is proposed. We focused on this triazolopyrazine as it is the core structure of the <i>in vivo </i>active anti-plasmodium compounds of Series 4 of the Open Source Malaria consortium.</p> <p> </p> <p>Archive of the electronic laboratory notebook with the description of all conducted experiments and raw NMR data could be accessed via following link <a href="https://ses.library.usyd.edu.au/handle/2123/21890">https://ses.library.usyd.edu.au/handle/2123/21890</a> . For navigation between entries of laboratory notebook please use file "Strings for compounds in the article.pdf" that works as a reference between article codes and notebook codes, also this file contain SMILES for these compounds. </p><br><p></p>

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