Development of an eccentric cam-based active pre-alignment system for the compact linear collider main beam quadrupole magnet

2010 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
F. Lackner ◽  
K. Artoos ◽  
C. Collette ◽  
H. M. Durand ◽  
C. Hauviller ◽  
...  

Compact linear collider (CLIC) is a study for a future electron–positron collider that would allow physicists to explore a new energy region beyond the capabilities of today's particle accelerators. The demanding transverse and vertical beam sizes and emittance specifications are resulting in stringent alignment and a nanometre stability requirement. In the current feasibility study, the main beam quadrupole magnets have to be actively pre-aligned with a precision of 1 µm in five degrees of freedom before being mechanically stabilized to the nanometre scale above 1 Hz. This contribution describes the approach of performing this active pre-alignment based on an eccentric cam system. In order to limit the amplification of the vibration sources at resonant frequencies, a sufficiently high eigenfrequency is required. Therefore, the contact region between cam and support was optimized for adequate stiffness based on the Hertzian theory. Furthermore, practical tests performed on a single-degree-of-freedom mockup will show the limitation factors and further improvements required for successful integration in a full-scale quadrupole mockup presently under design.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonas Bundschuh ◽  
Laura A. M. D’Angelo ◽  
Herbert De Gersem

AbstractThe finite element method is widely used in simulations of various fields. However, when considering domains whose extent differs strongly in different spatial directions a finite element simulation becomes computationally very expensive due to the large number of degrees of freedom. An example of such a domain are the cables inside of the magnets of particle accelerators. For translationally invariant domains, this work proposes a quasi-3-D method. Thereby, a 2-D finite element method with a nodal basis in the cross-section is combined with a spectral method with a wavelet basis in the longitudinal direction. Furthermore, a spectral method with a wavelet basis and an adaptive and time-dependent resolution is presented. All methods are verified. As an example the hot-spot propagation due to a quench in Rutherford cables is simulated successfully.


2016 ◽  
Vol 31 (33) ◽  
pp. 1644026 ◽  
Author(s):  
Haijun Yang

The Circular Electron Positron Collider (CEPC) as a Higgs factory was proposed in September 2013. The preliminary conceptual design report was completed in 2015.1 The CEPC detector design was using International Linear Collider Detector — ILD2 as an initial baseline. The CEPC calorimeters, including the high granularity electromagnetic calorimeter (ECAL) and the hadron calorimeter (HCAL), are designed for precise energy measurements of electrons, photons, taus and hadronic jets. The basic resolution requirements for the ECAL and HCAL are about 16%[Formula: see text][Formula: see text] (GeV) and 50%[Formula: see text][Formula: see text] (GeV), respectively. To fully exploit the physics potential of the Higgs, [Formula: see text], [Formula: see text] and related Standard Model processes, the jet energy resolution is required to reach 3%–4%, or 30%/[Formula: see text] (GeV) at energies below about 100 GeV. To achieve the required performance, a Particle Flow Algorithm (PFA) — oriented calorimetry system is being considered as the baseline design. The CEPC ECAL detector options include silicon–tungsten or scintillator–tungsten structures with analog readout, while the HCAL detector options have scintillator or gaseous detector as the active sensor and iron as the absorber. Some latest R&D studies about ECAL and HCAL within the CEPC working group is also presented.


Author(s):  
Brian J. Slaboch ◽  
Philip Voglewede

This paper introduces the Underactuated Part Alignment System (UPAS) as a cost-effective and flexible approach to aligning parts in the vertical plane prior to an industrial robotic assembly task. The advantage of the UPAS is that it utilizes the degrees of freedom (DOFs) of a SCARA (Selective Compliant Assembly Robot Arm) type robot in conjunction with an external fixed post to achieve the desired part alignment. Three path planning techniques will be presented that can be used with the UPAS to achieve the proper part rotation.


Author(s):  
Philipp Roloff ◽  
Ulrike Schnoor ◽  
Rosa Simoniello ◽  
Boruo Xu

AbstractThe Compact Linear Collider (CLIC) is a future electron–positron collider that will allow measurements of the trilinear Higgs self-coupling in double Higgs boson events produced at its high-energy stages with collision energies from $$\sqrt{s}$$ s  = 1.4 to 3 TeV. The sensitivity to the Higgs self-coupling is driven by the measurements of the cross section and the invariant mass distribution of the Higgs-boson pair in the W-boson fusion process, $$\text {e}^{+}\text {e}^{-}\rightarrow {\text {H}\text {H}\nu \bar{\nu }}$$ e + e - → HH ν ν ¯ . It is enhanced by including the cross-section measurement of ZHH production at 1.4 TeV. The expected sensitivity of CLIC for Higgs pair production through W-boson fusion is studied for the decay channels $$\mathrm{b}\bar{\mathrm{b}}\mathrm{b}\bar{\mathrm{b}}$$ b b ¯ b b ¯   and $$\mathrm{b}\bar{\mathrm{b}}\mathrm{W}\mathrm{W}^{*}$$ b b ¯ W W ∗   using full detector simulation including all relevant backgrounds at $$\sqrt{s}$$ s = 1.4 TeV with an integrated luminosity of $$\mathcal {L}$$ L  = 2.5 ab$$^{-1}$$ - 1 and at $$\sqrt{s}$$ s = 3 TeV with $$\mathcal {L}$$ L  = 5 ab$$^{-1}$$ - 1 . Combining $$\text {e}^{+}\text {e}^{-}\rightarrow {\text {H}\text {H}\nu \bar{\nu }}$$ e + e - → HH ν ν ¯ and ZHH  cross-section measurements at 1.4 TeV with differential measurements in $$\text {e}^{+}\text {e}^{-}\rightarrow {\text {H}\text {H}\nu \bar{\nu }}$$ e + e - → HH ν ν ¯ events at 3 TeV, CLIC will be able to measure the trilinear Higgs self-coupling with a relative uncertainty of $$-8\%$$ - 8 % and $$ +11\%$$ + 11 % at 68% C.L., assuming the Standard Model. In addition, prospects for simultaneous constraints on the trilinear Higgs self-coupling and the Higgs-gauge coupling HHWW are derived based on the $${\text {H}\text {H}\nu \bar{\nu }}$$ HH ν ν ¯ measurement.


Author(s):  
Dan Yu ◽  
Manqi Ruan ◽  
Vincent Boudry ◽  
Henri Videau ◽  
Jean-Claude Brient ◽  
...  

AbstractThe Circular Electron Positron Collider and the International Linear Collider are two electron-positron Higgs factories. They are designed to operate at a center-of-mass energy of 240 and 250 GeV and accumulate 5.6 and 2 $$ab^{-1}$$ab-1 of integrated luminosity. This paper estimates their performance on the $$H \rightarrow \tau ^{+}\tau ^{-}$$H→τ+τ- benchmark measurement. Using the full simulation analysis, the CEPC is expected to measure the signal strength to a relative accuracy of 0.8%. Extrapolating to the ILC setup, we conclude the ILC can reach a relative accuracy of 1.1% or 1.2%, corresponding to two benchmark beam polarization setups. The physics requirement on the mass resolution of the Higgs boson with hadronic decay final states is also discussed, showing that the CEPC baseline design and reconstruction fulfill the accuracy requirement of the $$H\rightarrow \tau ^{+}\tau ^{-}$$H→τ+τ- signal strength.


2015 ◽  
Vol 30 (33) ◽  
pp. 1550192 ◽  
Author(s):  
Mitsuru Kakizaki ◽  
Shinya Kanemura ◽  
Mariko Kikuchi ◽  
Toshinori Matsui ◽  
Hiroshi Yokoya

In the Minimal Supersymmetric Standard Model (MSSM), the bottom Yukawa coupling of the Higgs boson can considerably deviate from its Standard Model prediction due to nondecoupling effects. We point out that the ratio of the Higgs boson decay branching fraction to a bottom quark pair and that to a W-boson pair from the same production channel is particularly sensitive to large additional MSSM Higgs boson mass regions at future electron–positron colliders. Based on this precision measurement, we explicitly show the indirect discovery reach of the additional Higgs bosons according to planned programs of the International Linear Collider.


2010 ◽  
Vol 76 (3-4) ◽  
pp. 329-335 ◽  
Author(s):  
WENMIN ZHANG ◽  
M. Y. YU ◽  
A. R. KARIMOV ◽  
L. STENFLO

AbstractNonlinear coupling of the motion in the three spatial degrees of freedom of a cold fluid electron–positron plasma is investigated. Exact solutions describing expanding flows with oscillations are obtained. It is found that the energy in the irrotational flow component is in general transferred to the rotational components, but not in the reversed direction. Furthermore, since the density evolution need not be related to all the three flow components, oscillations in one or two of the flow fields can be purely electromagnetic and are not accompanied by density oscillations.


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