A merged quadrupole-calorimeter for CEPC

2016 ◽  
Vol 31 (33) ◽  
pp. 1644025 ◽  
Author(s):  
Richard Talman ◽  
John Hauptman
Keyword(s):  
Storage Ring ◽  
Free Space ◽  
Intersection Point ◽  
Active Particle ◽  
Cylindrical Shape ◽  
Particle Detector ◽  
Particle Detection ◽  
Quadrupole Field ◽  
Half Length ◽  
Colliding Beams

The luminosity [Formula: see text] of colliding beams in a storage ring such as CEPC depends strongly on [Formula: see text], the half-length of the free space centered on the intersection point (IP). [Formula: see text] is also the length from the IP to the front edges of the two near-in quadrupoles that are focusing the counter-circulating beams to the IP spot. The detector length cannot, therefore, exceed [Formula: see text]. Since [Formula: see text] increases strongly with decreasing [Formula: see text], there is incentive for reducing [Formula: see text]; but this requires the detector to be shorter than desirable. This paper proposes a method for integrating these adjacent quadrupoles into the particle detector to retain (admittedly degraded) active particle detection of those forward going particles that would otherwise be obscured by the quadrupole. A gently conical quadrupole shape is more natural for merging the quadrupole into the particle detector than is the analytically exact cylindrical shape. This is true whether or not the calorimeter is integrated. It will be the task of accelerator physicists to determine the extent to which deviation from the pure quadrupole field compromises (or improves) accelerator performance. Superficially, both the presence of strongest gradient close to the IP and largest aperture farther from the IP seem to be advantageous. A tentative design for this merged, quadrupole-calorimeter is given.

scholarly journals Circular depolarization ratios of single water droplets and finite ice circular cylinders: a modeling study

2012 ◽  
Vol 12 (9) ◽  
pp. 4207-4214 ◽  
Author(s):  
M. Nicolet ◽  
M. Schnaiter ◽  
O. Stetzer
Keyword(s):  
Polarized Light ◽  
Ice Crystals ◽  
Particle Orientation ◽  
Circular Cylinders ◽  
Cylindrical Shape ◽  
Water Droplets ◽  
Particle Detection ◽  
Phase Discrimination ◽  
The Difference ◽  
Depolarization Ratios

Abstract. Computations of the phase matrix elements for single water droplets and ice crystals in fixed orientations are presented to determine if circular depolarization δC is more accurate than linear depolarization for phase discrimination. T-matrix simulations were performed to calculate right-handed and left-handed circular depolarization ratios δ+C, respectively δ−C and to compare them with linear ones. Ice crystals are assumed to have a circular cylindrical shape where their surface-equivalent diameters range up to 5 μm. The circular depolarization ratios of ice particles were generally higher than linear depolarization and depended mostly on the particle orientation as well as their sizes. The fraction of non-detectable ice crystals (δ<0.05) was smaller considering a circular polarized light source, reaching 4.5%. However, water droplets also depolarized light circularly for scattering angles smaller than 179° and size parameters smaller than 6 at side- and backscattering regions. Differentiation between ice crystals and water droplets might be difficult for experiments performed at backscattering angles which deviate from 180° unlike LIDAR applications. Instruments exploiting the difference in the P44/P11 ratio at a scattering angle around 115° are significantly constrained in distinguishing between water and ice because small droplets with size parameters between 5 and 10 do cause very high circular depolarizations at this angle. If the absence of the liquid phase is confirmed, the use of circular depolarization in single particle detection is more sensitive and less affected by particle orientation.

scholarly journals Comprehensive Improvement of the Sensitivity and Detectability of a Large-Aperture Electromagnetic Wear Particle Detector

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3162 ◽  
Author(s):  
Ran Jia ◽  
Biao Ma ◽  
Changsong Zheng ◽  
Xin Ba ◽  
Liyong Wang ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Wear Particle ◽  
Impedance Change ◽  
Particle Detector ◽  
Particle Detection ◽  
Detection Range ◽  
Micro Particles ◽  
Mode Decomposition ◽  
Flux Change ◽  
Lock In

The electromagnetic wear particle detector has been widely studied due to its prospective applications in various fields. In order to meet the requirements of the high-precision wear particle detector, a comprehensive method of improving the sensitivity and detectability of the sensor is proposed. Based on the nature of the sensor, parallel resonant exciting coils are used to increase the impedance change of the exciting circuit caused by particles, and the serial resonant topology structure and an amorphous core are applied to the inductive coil, which improves the magnetic flux change of the inductive coil and enlarges the induced electromotive force of the sensor. Moreover, the influences of the resonance frequency on the sensitivity and effective particle detection range of the sensor are studied, which forms the basis for optimizing the frequency of the magnetic field within the sensor. For further improving the detectability of micro-particles and the real-time monitoring ability of the sensor, a simple and quick extraction method for the particle signal, based on a modified lock-in amplifier and empirical mode decomposition and reverse reconstruction (EMD-RRC), is proposed, which can effectively extract the particle signal from the raw signal with low signal-to-noise ratio (SNR). The simulation and experimental results show that the proposed methods improve the sensitivity of the sensor by more than six times.

Free-Space Excitation of Optofluidic Devices for Pattern-Based Single Particle Detection

2021 ◽  
pp. 1-1
Author(s):  
Md Nafiz Amin ◽  
Vahid Ganjalizadeh ◽  
Matt Hamblin ◽  
Aaron R. Hawkins ◽  
Holger Schmidt
Keyword(s):  
Single Particle ◽  
Free Space ◽  
Particle Detection ◽  
Single Particle Detection

scholarly journals Circular depolarization ratios of single water droplets and finite ice circular cylinders: a modeling study

2011 ◽  
Vol 11 (11) ◽  
pp. 30125-30144
Author(s):  
M. Nicolet ◽  
M. Schnaiter ◽  
O. Stetzer
Keyword(s):  
Polarized Light ◽  
Ice Crystals ◽  
Particle Orientation ◽  
Circular Cylinders ◽  
Cylindrical Shape ◽  
Water Droplets ◽  
Particle Detection ◽  
Phase Discrimination ◽  
Single Particle Detection ◽  
Depolarization Ratios

Abstract. Computations of the phase matrix elements for single water droplets and ice crystals in fixed orientations are presented to determine if circular depolarization δ&amp;pm;C is more accurate than linear depolarization for phase discrimination. T-matrix simulations were performed to calculate right-handed and left-handed circular depolarization ratios δ&amp;plus;C, respectively δ−C and to compare them with linear ones. Ice crystals are assumed to have a circular cylindrical shape where their surface-equivalent diameters range up to 5 μm. The circular depolarization ratios of ice particles were generally higher than linear depolarization and depended mostly on the particle orientation as well as their sizes. The fraction of non-detectable ice crystals (δ < 0.05) was smaller considering a circular polarized light source, reaching 4.5%. However, water droplets also depolarized light circularly for scattering angles smaller than 179° and size parameters smaller than 6 at side- and backscattering regions. Differentiation between ice crystals and water droplets might be difficult for experiments performing at backscattering angles which deviate from 180° unlike lidar applications. If the absence of the liquid phase is confirmed, the use of circular depolarization in single particle detection is more sensitive and less affected by particle orientation.

Principle and Experimental Study of a MEMS Explosive Particle Detector

2003 ◽  
Author(s):  
Yan Zhang ◽  
Tao Mei ◽  
Deyi Kong ◽  
Chengmei Zhang ◽  
Yongchun Tao ◽  
...  
Keyword(s):  
Melting Point ◽  
High Selectivity ◽  
Particle Detector ◽  
Sensor Surface ◽  
Particle Detection ◽  
Surface Absorption ◽  
Before And After ◽  
Step Heating ◽  
The Difference ◽  
Detecting Method

A new explosive particle detection with MEMS is presented in this paper, which utilize the properties of explosive particles. The principle of the detector is described firstly: every explosive has unique melting and evaporation point, when single explosive particle on the sensor surface melts and absorbs heat from it, the temperature change of the sensor will occurs. Unlike other indirect detecting method, a step heating method was proposed to control the working state of the sensor. The method had the advantages of easy implementation, active controlling and high selectivity: Firstly, the voltage will make the temperature of the sensor a little lower than the melting point of explosive, and the fusion of the explosive will not occur yet; With the voltage begin to increase again, the temperature of the sensor will also increase up to the melting point and produce a respond graph called base graph. The same voltage pulse was sent through the sensor before and after putting the explosive particles on the sensor surface. Absorption of heat from it during melting and evaporation causes its temperature changing and the shift on the respond graph is different from the former. Furthermore, experiments have been performed to confirm the feasibility to measure the temperature directly, and the graph is presented to show the difference between the changing with TNT sample existing or not, the resistance changing is apparent in graph when the temperature increase close to the melting point of TNT.

Free Space Excitation in Optofluidic Devices for Single Particle Detection

2019 ◽  
Author(s):  
M. N. Amin ◽  
M. Hamblin ◽  
G. G. Meena ◽  
A. R. Hawkins ◽  
H. Schmidt
Keyword(s):  
Single Particle ◽  
Free Space ◽  
Particle Detection ◽  
Single Particle Detection
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