DOCSLIB.ORG

KEK, Norihito Ohuchi 1. IR Magnets (ES, QCS, QC1)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
KEK, Norihito Ohuchi 1. IR Magnets (ES, QCS, QC1) SuperB.WS05.Hawaii IR Magnets for SuperKEKB KEK, Norihito Ohuchi 1. IR Magnets (ES, QCS, QC1) 2. Interference between Magnet-Cryostats and Belle 3. Summary SuperB.WS05.Hawaii IR Magnets - Required IR magnets from beam optics • Compensation solenoid (SC) – ESR and ESL, canceling the Belle solenoid field • Final focus quadrupole (SC) – QCSR and QCSL for both beams, ∫G dl QCSR= 11.99 (T/m)• m, ∫G dl QCSL= 14.33 • Special Quadrupole (NC or SC) – QC1RE, QC1LE for HER beam, ∫G dl QC1RE= 9.00, ∫G dl QC1LE= 9.92 • Special Quadrupole (NC) – QC2RE, QC2LE, QC2RP and QC2LP, ∫G dl QC2RE= 7.02, ∫G dl QC2LE= 6.80, ∫G dl QC2RP= 3.40, ∫G dl QC2LP= 4.02 IP QC2RE e- QC1RE HER e+ QC2LP ESL-1 QCSL 7 mrad 8 mrad Belle solenoid axis Beam-pipe axis QCSR LER 22 mrad QC1LE ESR-1 QC2RP ESL-2 ESR-2 QC2LE -5000.0 0.0 5000.0 SuperB.WS05.Hawaii IR Magnets - Spatial constraint for the design of the IR magnets • Physical aperture of beams – Determined by the beta function at the components and the beam acceptance (of which main sources are linac beam emittance and injection error). – Improvement of the beam acceptance by the damping ring for the positron beam. • SR envelops from QCS magnets – The intensities of the SR power are 179 kW and 64.6 kW from QCSR and QCSL, respectively. • The interference between the IR magnets and the detector components of Belle Belle boundary QC1R(SC)-cryostat-bore QC1L(SC)-cryostat-bore 150 QCSLA 150 QCSR-cryostat-bore QCSRA HER 100 QCSRC 100 QCSLC QCSRI QCSL-cryostat-bore 50 QCSLI 50 0 0 [mm] [mm] LER -50 -50 -100 -100 beam physical aperture SOR from the IP or arc sides of each QCS IP deviation of SOR from the central route -4000.0 0.0 4000.0 SuperB.WS05.Hawaii IR Magnets - Configuration of QCS and ES magnets (in the right side) • Compensation solenoid, ESR Magnet Operation Parameters – ESR is separated into two coil, ESR-1 and ESR-2. under the Belle field of 1.5 T – ESR-1 is placed in front of QCS-R, and ESR-2 is ESR-1 ESR-2 QCS-R overlaid on the outer surface of the QCS-R. I , A 647.2 647.2 1186.7 – The E.M.F. on the ESR induced by the Belle field is op 2.18×104N. Bmax, T 2.76 2.61 4.99 • Final focus quadrupole, QCS-R I /I , % 63 60 75 – The magnet consists of six layer coils. op c – The operation field gradient is 40.124 T/m, and the Length, mm 100 1000 456 effective magnetic length is 0.299 m. O.R., mm 95.5 173.8 116.8 R 219 ESR R 239 QCSR ESR-2 R 90 R 69 QCSR R 50 e+ ESR-1 8 7 4 e- R 85 R 209 R 194 1378.3 R 186 SuperB.WS05.Hawaii IR Magnets - Configuration of QCS and ES magnets (in the left side) Magnet Operation Parameters under 1.5 T • Compensation solenoid, ESL-1 and ESL-2 ESL-1 ESL-2 QCS-L – The E.M.F. on the ESL is 3.83×104N. I , A 656.2 656.2 1186.7 • Final focus quadrupole, QCS-L op 4.33 2.93 4.77 – The magnet cross section is the same as the QCS-R. Bmax, T – The operation field gradient is 40.124 T/m, and the Iop/Ic, % 80 56 74 effective magnetic length is 0.357 m. Length, mm 166 500 514 O.R., mm 94.6 183.6 116.8 R 230 ESL R 250 R 197 ESL-2 QCSL ESL-1 R 69 R 50 21.2 0 QCSL 0 47.8 5 R 72 R 90 R 116.1 1036.8 SuperB.WS05.Hawaii IR Magnets - QCS and ES magnets with Belle detector SuperB.WS05.Hawaii IR Magnets - Bz field profile along the Belle axis • The negative peaks are -3.62 T and -1.68 T in the left and the right side with respect to the IP, respectively. • The regions, where the field gradients are large, are closer to the IP than KEKB. Bz profile of SuperKEKB, T Bz-profile.SBWS05 2 Bz profile of KEKB, T 1 0 -1 T , z B -2 -1.68 T -3 -3.20 T -4 -3.62 T -4.40 T -5 -4 -3 -2 -1 0 1 2 3 4 z, m SuperB.WS05.Hawaii IR Magnets - Bz field profile in the Belle detector • The Bz profile in the large volume of the Belle detector is almost same as that of KEKB. • In the area near the magnets and the IP, the profile shows a large difference from that of KEKB. – In this area, the field mapping should be performed, again. Bz profile from 1.2 T to 1.6 T in the Belle detector Belle Solenoid ESL-2 ESL-1 ESR-1 ESR-2 Belle center IR Magnets SuperB.WS05.Hawaii - QC1-RE and QC-1LE (Super-conducting or Normal-conducting) • Normal-conducting type – Cu hollow conductor – Trim and backleg coils for the field correction Magnet Parameters (QC-1RE) – Unwanted multipole fields at the fringes (Ex, skew octupole) Normal Super • Super-conducting type G, T/m 12.0 27.67 – Nb-Ti rectangular solid cable – Corrector coils same as the QCS magnets for final alignment L, m 0.75 0.328 – Cryostat inner bore works as the function of the beam pipe. I , A 3700 539.4 • Careful consideration for the cryostat dislocation induced by op the beam pipe. Turns/pole 3 130 – An additional helium refrigerator is needed. – Careful consideration for magnet quench induced by beams since β is maximum at QC1s. Super-conducting QC1-RE Normal-conducting QC1-RE Cryostat ø570 ø420 R 59.17 R 78.17 R 85.17 SC Coil Iron Yoke SuperB.WS05.Hawaii IR Magnets - QC1-RE and QC1-LE (Super-conducting or Normal-conducting) Normal Super Magnet Parameters G, T/m 15.54 51.34 (QC1-LE) L, m 0.64 0.195 Iop, A 1300 419.9 Turns/pole 3 100 Super-conducting QC1-LE Normal-conducting QC1-LE ø420.0 ø300.0 R 17.4 R 26.39 R 32.9 R 34.89 SC Coil Iron Yoke Cryostat SuperB.WS05.Hawaii Interference between Magnet-Cryostats and Belle - Cryostat design of QCS and ES IP Requirement from the Belle group QCSL-CENTER(z-direction) 969.4 – Redesigning cryostat configuration to ESL-2 ESL-1 ° 0 reduce the Rad. Bhabha BG 0 . 0 pointed by M. Sallivan in 6th HLWS, 2004 3 0 QCSL 2 . 0 5 1 reported by O. Tajima in this meeting 2 QCSL-CENTER(H) Introducing the heavy metal (Tungsten alloy) as one of the magnet structural materials. Necessary to modify the support system of the 97W-4Ni-1Cu liquid helium vessel – Increasing the space between the 130 85 detector and the cryostat for wiring 1163.3 QCS-CENTER ESR-2 the cables 1 7 . 0 0 ° ESR-1 QCSR ESR and ESL solenoids were calculated again, and the fronts of the cryostats were re-designed. The created space in radial direction : 25 mm for ESR 38 mm for ESL SuperB.WS05.Hawaii Interference between Magnet-Cryostats and Belle - Support design of QCS and ES • Support system – The system consists of 8 rods (titanium alloy) for one cryostat. • Change of the cryostat weight by the heavy metal – Right : 492 kg ⇒ 608 kg Liquid Helium vessel – Left : 451 kg ⇒ 596 kg 4.7 K • Heat load via 8 rods < 4 W – Requirement from the cryogenic system Vacuum vessel room temp. Left Right 300 K Rod diameter, mm 7 6 4.7 K Rod length, mm 65 65 EMF Calculated stress of rod, N/mm2 306 290 Allowable stress at R.T., N/mm2 400 400 W Total heat load (eight rods), W 1.92 1.44 SuperB.WS05.Hawaii Interference between Magnet-Cryostats and Belle - Belle end-cap, QC1 and movable table for IR magnets Cryogenic transfer tube Accelerator components around the Belle end-cap iron yoke ø60.5 ø114.3 • QC1 ø45.3 – The cryostat for the SC QC1 is slightly larger than the NC QC1. ø42.7 ø48.6 • Transfer tube from the cryostat of ES and QCS ø39.4 – The outer diameter of transfer tube is modified from 216.3 mm (KEKB) to ø8 114.3 mm. • Movable table for the IR magnets – As the material of the table, the thickness of the SUS plate is assumed to be 40 mm as same as that of KEKB. ø72.1 ø76.3 Summary SuperB.WS05.Hawaii The 3-D field calculations of the QCS and ES magnets have been completed. These magnets have sufficient operation margin for the Super-KEKB. The field profile in the Belle was calculated for the modified model of the ES magnets. This profile around the IP and the cryostats should be checked by the Belle group. QC1 magnets in the normal-conducting and super-conducting types are designed and compared. We should do the further study for both magnets, ex., 3-D field calculation, effect of the field profile on the beam optics and handling in the actual operation. For shielding the Rad. Bhabha BG, application of the heavy metal was studied as the material of the magnet components in the cryostat. The heavy metal does not have a large effect on the cryogenic design at LHe temperature. The interference between the Belle end-cap iron yoke, cryogenic transfer tube and QC1 is manageable at present.
Load more

Recommended publications
  • Superkekb VACUUM SYSTEM K
    SuperKEKB VACUUM SYSTEM K. Shibata#, KEK, Tsukuba, Japan Abstract size in the horizontal and vertical directions at the IP, I is SuperKEKB, which is an upgrade of the KEKB B- the beam current, y is the vertical beam-beam * factory (KEKB), is a next-generation high-luminosity parameter, y is the vertical beta function at the IP, RL electron-positron collider. Its design luminosity is 8.0× and Ry are the reduction factors for the luminosity and 1035 cm-2s-1, which is about 40 times than the KEKB’s vertical beam-beam tune-shift parameter, respectively, record. To achieve this challenging goal, bunches of both owing to the crossing angle and the hourglass effect. The beams are squeezed extremely to the nanometer scale and subscripts + and – indicate a positron or electron, the beam currents are doubled. To realize this, many respectively. At the SuperKEKB, crossing the beams by upgrades must be performed including the replacement of using the “nanobeam scheme” [3] makes it possible to * th beam pipes mainly in the positron ring (LER). The beam squeeze y to about 1/20 of KEKB’s size. In the pipes in the LER arc section are being replaced with new nanobeam scheme, bunches of both beams are squeezed aluminium-alloy pipes with antechambers to cope with extremely to the nanometer scale (0.3 mm across and 100 the electron cloud issue and heating problem. nm high) and intersect only in the highly focused region Additionally, several types of countermeasures will be of each bunch at a large crossing angle (4.8 degrees).
    [Show full text]
  • First New Particle-‐Smasher Since the LHC Comes
    www.coepp.org.au Media release for immediate release Thursday 3 March 2016 First new particle-smasher since the LHC comes online A new particle collider, SuperKEKB, located at the KEK laboratory in Tsukuba, Japan has achieved “First Turns” and is now in the test operation stage. This is the newest “particle-smasher” to go online since the LHC at CERN in Geneva. SuperKEKB will be the world’s highest-luminosity collider and, in association with the Belle II experiment, it will collide electrons with their antiparticles – positrons – in the search for new physics. Designed and built at KEK by a team of Japanese accelerator physicists, SuperKEKB, along with the Belle II detector at the interaction point, will search for new physics beyond the Standard Model by measuring rare decays of elementary particles such as beauty quarks, charm quarks and tau leptons. In contrast to the LHC, which is the world's highest energy machine, SuperKEKB/Belle II is designed to have the world’s highest luminosity or rate of collisions (40 times higher than its predecessor KEKB). This will make SuperKEKB the world’s “highest luminosity” machine and the leading accelerator on the “luminosity frontier”. Key milestones: • 10 February, 2016: SuperKEKB succeeded in circulating and storing a positron beam moving close to the speed of light around the 3.0 kilometre circumference of its main ring. • 26 February, 2016: SuperKEKB electron-positron collider succeeded in circulating and storing a seven billion electron-volt energy (7 GeV) electron beam around its ring of magnets in the opposite direction. The achievement of these “first turns” – i.e.
    [Show full text]
  • KEKB and Superkekb Design*)
    Low emi(ance rings: Colliders mainly based on experiences of KEKB and SuperKEKB design*) Y. Funakoshi KEK *) Based on the works done by KEK/SuperKEKB opcs group members: K. Oide, H. Koiso, Y. Ohnishi, A. Morita, H. Sugimoto Comparison of emi(ances of colliders Comparison of emi(ances of colliders Future colliders LEP3 Exisng colliders TLEP-H From Beam Dynamics Newsle(er No. 31 Courtesy of F. Zimmermann, H. Burkhardt and Q. Qin F. Zimmmerman Comparison of emi(ances of colliders [cont’d] Future colliders Exisng colliders LEP3 TLEP-H Necessity of low emi(ance in colliers Importance of verFcal emi(ance • In many high luminosity colliders such as KEKB and PEP-II, the machines were operated well above the beam-beam limit. Usually the verFcal beam-beam limit is lower than the horizontal one. • Even above the beam-beam limit, the luminosity increases linearly as funcFon of the beam currents. • In this situaon, it is commonly considered that the verFcal emi(ance in single beam is not important for the luminosity, since the verFcal emi(ance is determined by the beam-beam blowup. • However, the beam-beam simulaon predicts that the smaller verFcal emi(ance in single beam is important for a higher luminosity. • In some machines such as SuperKEKB, SuperB and TLEP, a very low verFcal emi(ance is necessary to achieve the design beam-beam parameter. Simulaon: KEKB Luminosity vs. VerFcal emi(ance (single beam) KEKB Achieved: 0.24nm, σy = 1.18µm (LER) Simulaon by K. Ohmi εy(nm) • Smaller verFcal emi(ance always gives be(er performance.
    [Show full text]
  • The Belle II Experiment: Status and Prospects
    universe Article The Belle II Experiment: Status and Prospects Paolo Branchini † INFN Sezione di RomaTre Via Della Vasca Navale, 84, 00146 Roma, Italy; [email protected] † On behalf of the Belle II Collaboration. Received: 16 September 2018; Accepted: 29 September 2018; Published: 1 October2018 Abstract: The Belle II experiment is a substantial upgrade of the Belle detector and will operate at the SuperKEKBenergy-asymmetric e+e− collider. The accelerator has already successfully completed the first phase of commissioning in 2016. The first electron versus positron collisions in Belle II were delivered in April 2018. The design luminosity of SuperKEKB is 8 × 1035 cm−2 s−1, and the Belle II experiment aims to record 50 ab−1 of data, a factor of 50 more than the Belle experiment. This large dataset will be accumulated with low backgrounds and high trigger efficiencies in a clean e+e− environment. This contribution will review the detector upgrade, the achieved detector performance and the plans for the commissioning of Belle II. Keywords: flavor; dark matter 1. Introduction Even though the Standard Model (SM) is currently the best description of the subatomic world, it does not explain the complete picture. The theory incorporates only three out of the four fundamental forces, omitting gravity. Moreover, there are also important questions that it does not answer, such as the matter versus antimatter asymmetry in the number of quark and lepton generations. Many New Physics (NP) scenarios have been proposed. Experiments in high-energy physics search for NP using two complementary approaches. The first, at the energy frontier, is able to discover new particles directly produced in pp collisions (ATLAS, CMS).
    [Show full text]
  • Movable Collimator System for Superkekb
    PHYSICAL REVIEW ACCELERATORS AND BEAMS 23, 053501 (2020) Movable collimator system for SuperKEKB T. Ishibashi , S. Terui, Y. Suetsugu, K. Watanabe, and M. Shirai High Energy Accelerator Research Organization (KEK), 305-0801, Tsukuba, Japan (Received 3 March 2020; accepted 6 May 2020; published 13 May 2020) Movable collimators for the SuperKEKB main ring, which is a two-ring collider consisting of a 4 GeV positron and 7 GeVelectron storage ring, were designed to fit an antechamber scheme in the beam pipes, to suppress background noise in a particle detector complex named Belle II, and to avoid quenches, derived from stray particles, in the superconducting final focusing magnets. We developed horizontal and vertical collimators having a pair of horizontally or vertically opposed movable jaws with radiofrequency shields. The collimators have a large structure that protrudes into the circulating beam and a large impedance. Therefore, we estimated the impedance using an electromagnetic field simulator, and the impedance of the newly developed collimators is lower compared with that of our conventional ones because a part of each movable jaw is placed inside the antechamber structure. Ten horizontal collimators and three vertical collimators were installed in total, and we installed them in the rings taking the phase advance to the final focusing magnets into consideration. The system generally functioned, as expected, at a stored beam current of up to approximately 1 A. In high-current operations at 500 mA or above, the jaws were occasionally damaged by hitting abnormal beams, and we estimated the temperature rise for the collimator’s materials using a Monte Carlo simulation code.
    [Show full text]
  • Mvillanueva Tau-Workshop-2018.Pdf
    Prospects for � lepton physics at Belle II Michel Hernández Villanueva Outline: Department of Physics Cinvestav, Mexico • Achievements of B-factories in � lepton physics. On behalf of the Belle II collaboration • The Belle II experiment. 15th International Workshop on • First results with early data. Tau Lepton Physics • Prospects of � lepton Amsterdam, Netherlands, Sep 24, 2018 physics Rap God – Eminem B Factories • B-Factory: Production of b pairs. • � factory too! �(e+e- —> �(4s)) = 1.05 nb �(e+e- —> � �) = 0.92 nb Michel H. Villanueva 2 � lepton physics results at B factories Lint (fb-1) Lifetime and CPT test CP-Violation LFV limits Mass and CPT test CP-Violation LFV limits Limits in Mass and CPT test τ → μγ SCC searches Belle Limits in τ → ℓℓℓ BaBar Electric Limits in dipole limit τ → μγ τ → ℓℓℓ Michel H. Villanueva 3 Next gen: Belle II collaboration • 800+ members, 108 institutions, 25 countries • Located in KEK at Tsukuba, Japan Mt. Tsukuba Linac Michel H. Villanueva 4 Next gen: SuperKEKB • Super B-Factory (And � factory too!) �(e+e- —> �(4s)) = 1.05 nb �(e+e- —> � �) = 0.92 nb • Integrated luminosity expected: 50 ab-1 (x50 than previous B factories) 4.6x1010 � pairs @KEK Tsukuba, Japan Michel H. Villanueva 5 Next gen: SuperKEKB “Nano-beams”: vertical beam size is 50nm at the IP. KEKB • Challenges at L=8x1035 1/cm2/s: - Higher background (Radiative Bhabha, Touschek, beam- SuperKEKB gas scattering, etc.). - Higher trigger rates (High performance DAQ, computing). Michel H. Villanueva 6 Belle II Detector Michel H. Villanueva 7 SuperKEKB luminosityBelle II Schedule projection Data taking in phase II was performed with all Goal of Be!e II/SuperKEKB subsystems, except vertex detectors.
    [Show full text]
  • The Belle II Experiment at the Superkekb
    EPJ Web of Conferences 218, 07003 (2019) https://doi.org/10.1051/epjconf/201921807003 PhiPsi 2017 The Belle II Experiment at the SuperKEKB Chang-Zheng Yuan (for the Belle II Collaboration )1;2;? 1Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China 2University of Chinese Academy of Sciences, Beijing 100049, China Abstract. Belle II experiment at the SuperKEKB collider is a major upgrade of the Belle experiment at the KEKB asymmetric e+e− collider at the KEK. The experiment will focus on the search for new physics beyond the standard model via high precision measurement of heavy flavor decays and search for rare signals. In this talk, we present the status of the SuperKEKB collider and the Belle II detector. 1 Introduction The two B factories, Belle at the KEKB collider at KEK [1] and BaBar at the PEP II collider at SLAC [2], have been operating very successfully for more than ten years [3]. Altogether, about 1.5 ab−1 data in the vicinity of the Υ(4S ) resonance were accumulated, and these data were used in extensive studies of the B-physics, charm physics, tau physics, as well as hadron spectroscopy and various searches for possible hints of new physics, such as lepton number violation, low mass Higgs-like states, and dark matters. While most results from B factories are in good consistency with the expectations from the Stan- dard Model (SM), there are a few measurements that show discrepancies at around three standard deviation level from the SM predictions. One of the interesting examples is the possible observation of the violation of the lepton universality in semileptonic B decays, if confirmed, very probably, there is contribution from non-SM physics [4].
    [Show full text]
  • BUNCH by BUNCH FEEDBACK SYSTEMS for SUPERKEKB RINGS Makoto Tobiyama†, John W
    Proceedings of the 13th Annual Meeting of Particle Accelerator Society of Japan August 8-10, 2016, Chiba, Japan PASJ2016 TUOM06 BUNCH BY BUNCH FEEDBACK SYSTEMS FOR SUPERKEKB RINGS Makoto Tobiyama†, John W. Flanagan, KEK Accelerator Laboratory, 1-1 Oho, Tsukuba 305-0801, Japan, and Graduate University for Advanced Studies (SOKENDAI), 1-1, Oho, Tsukuba 305-0801, Japan Alessandro Drago, INFN-LNF, Via Enrico Fermi 40-00044, Frascati(Roma), Italy Abstract analysed by the unstable mode analysis with the grow- Bunch by bunch feedback systems for the SuperKEKB damp experiments. Also the related beam diagnostic tools rings have been developed. Transverse and longitudinal such as the bunch current monitor, large scale memory bunch feedback systems brought up in very early stages board, will be shown. of beam commissioning have shown excellent perfor- Table1: Main Parameters of SuperKEKB HER/LER in mance, and helped realize smooth beam storage and very Phase 1 Operation. quick vacuum scrubbing. Also, via grow-damp experi- ments and unstable mode analysis, they contributed to HER LER finding the possible source of an instability. The measured performance of the bunch feedback systems, together Energy (GeV) 7 4 with the performance of the bunch feedback related sys- Circumference(m) 3016 tems such as the bunch current monitor and betatron tune monitor are reported. Max. Beam current (mA) 1010 870 Max. Number of bunches 2455 2363 INTRODUCTION The KEKB collider has been upgraded to the Single bunch current (mA) 1.04 1.44 SuperKEKB collider with the final target of 40 times Min. bunch separation(ns) 4 higher luminosity than that of KEKB.
    [Show full text]
  • Accelerator Design at Superkekb
    Prog. Theor. Exp. Phys. 2013, 03A011 (17 pages) DOI: 10.1093/ptep/pts083 KEKB Accelerator Accelerator design at SuperKEKB Yukiyoshi Ohnishi∗, Tetsuo Abe, Toshikazu Adachi, Kazunori Akai, Yasushi Arimoto, Kiyokazu Ebihara, Kazumi Egawa, John Flanagan, Hitoshi Fukuma, Yoshihiro Funakoshi, Kazuro Furukawa, Takaaki Furuya, Naoko Iida, Hiromi Iinuma, Hoitomi Ikeda, Downloaded from Takuya Ishibashi, Masako Iwasaki, Tatsuya Kageyama, Susumu Kamada, Takuya Kamitani, Ken-ichi Kanazawa, Mitsuo Kikuchi, Haruyo Koiso, Mika Masuzawa, Toshihiro Mimashi, Takako Miura, Takashi Mori, Akio Morita, Tatsuro Nakamura, Kota Nakanishi, Hiroyuki Nakayama, Michiru Nishiwaki, Yujiro Ogawa, Kazuhito Ohmi, Norihito Ohuchi, Katsunobu Oide, Toshiyuki Oki, Masaaki Ono, Masanori Satoh, http://ptep.oxfordjournals.org/ Kyo Shibata, Masaaki Suetake, Yusuke Suetsugu, Ryuhei Sugahara, Hiroshi Sugimoto, Tsuyoshi Suwada, Masafumi Tawada, Makoto Tobiyama, Noboru Tokuda, Kiyosumi Tsuchiya, Hiroshi Yamaoka, Yoshiharu Yano, Mitsuhiro Yoshida, Shin-ichi Yoshimoto, Demin Zhou, and Zhanguo Zong High Energy Accelerator Research Organization, KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan ∗E-mail: [email protected] at High Energy Accelerator Research Organization(KEK) on August 14, 2013 Received September 25, 2012; Accepted November 13, 2012; Published March 26, 2013 ............................................................................... The SuperKEKB project requires a positron and electron collider with a peak luminosity of 8 × 1035 cm−2 s−1. This luminosity is 40 times that of the KEKB B-factory, which operated for 11 years up to 2010. SuperKEKB is an asymmetry-energy and double-ring collider; the beam energy of the positron (LER) is 4 GeV and that of the electron (HER) is 7 GeV.An extremely small beta function at the interaction point (IP) and a low emittance are necessary.
    [Show full text]
  • The Belle-II Experiment at Superkekb
    The Belle II Experiment at SuperKEKB Changzheng Yuan (苑长征) (for the Belle II Collaboration) IHEP, Beijing Hefei, May 25, 2012 1 Belle / KEKB / KEK Tokyo (45 mins by Tsukuba Exps) KEKB: e- (HER): 8.0 GeV e+ (LER): 3.5 GeV crossing angle: 22 mrad ECM=M(U(4S)) also at 1S, 2S, 5S e- 2010 Ldt = 1020 fb-1 e+ 1999 (1.02 ab-1) Peak lumi record at KEKB: L=2.1 x 1034/cm2/s with crab cavities2 Physics at a SuperB Factory • There is a good chance to see new phenomena: – CPV in from the new physics (non KM). – Lepton flavor violations in t decays. • They will help to diagnose (if found) or constrain (if not found) new physics models. • Btn, Dtn can probe the charged Higgs in large tanb region. • Physics motivation is independent of LHC. – If LHC finds NP, precision flavour physics is compulsory. – If LHC finds no NP, high statistics B/t decays would be a unique way to search for the >TeV scale physics [very probably if Mhiggs~125 GeV]. There are many more topics: CPV in charm, new hadrons, … Recent update of the physics reach with 50 ab-1 (75 ab-1): Physics at Super B Factory (Belle II authors + guests) hep-ex > arXiv:1002.5012 3 SuperB Progress Reports: Physics (SuperB authors + guests) hep-ex > arXiv:1008.1541 Search for New Physics Sensitivity to new physics B+t + n with charged Higgs t 0.38 0.35 Br(B tn ) (1.65 )10 4 0.37 0.37 In the SM 0.11 4 0.76 0.06 10 CKM fit Searches for lepton flavour violation in tau decays In the SM the lepton flavour violation decays are extremely small: Br(tl) 1054 4 Br(t 3 leptons) 1014 Hadron spectroscopy at B
    [Show full text]
  • Belle II/Superkekb: New Physics and the Next Generation Tom Browder, University of Hawai’I at Manoa
    Belle II/SuperKEKB: New Physics and the Next Generation Tom Browder, University of Hawai’i at Manoa Introduction, History and Motivation: What’s happening in high energy physics ? Some Highlights from First Collisions and the Phase 2 Belle II Pilot Run. The complex superconducting final focus is partially visible here (before closing the endcap). Physics and the Road Ahead to Phase 3, the first Physics run Vertex detector before Conclusion; opportunities installation for Vietnam The Geography of the International Belle II collaboration Belle II now has grown to ~800 researchers from 26 countries This is rather unique in Japan and Asia. The only comparable example is the T2K experiment at JPARC, which is also an international collaboration Including one very good one from Vietnam, Dong Van Thanh Youth and potential: There are ~267 graduate students in the collaboration What is happening these days in high energy physics ? (Personal perspective, based on trips to international conferences and summer schools.) Typical scenes in Hanoi, Vietnam NY Times on Aug 5, 2016 2016: US Some other media Belle II headlines on ICHEP: summer school, “Physicists look to @PNNL in the future as new Richland, particle dream dies” Washington “Particle Physics in Mourning” “The End of the Beginning” Friday August 5, 2016 at ICHEP in Chicago, the ATLAS and CMS collaborations announced that the 750 GeV di-photon excess had disappeared in the large Run II 13 TeV dataset. 2017 US Belle II School@Ole Miss New York Times, June 19, 2017 But since then, the silence from the energy frontier has been ominous.
    [Show full text]
  • First Simultaneous Detection of Electron and Positron Bunches at the Positron Capture Section of the Superkekb Factory
    First Simultaneous Detection of Electron and Positron Bunches at the Positron Capture Section of the SuperKEKB Factory Tsuyoshi Suwada ( [email protected] ) High Energy Accelerator Research Organization Muhammad Abdul Rehman High Energy Accelerator Research Organization Fusashi Miyahara High Energy Accelerator Research Organization Research Article Keywords: electron, positron bunch signals, wideband pickups Posted Date: February 24th, 2021 DOI: https://doi.org/10.21203/rs.3.rs-235736/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License First simultaneous detection of electron and positron bunches at the positron capture section of the SuperKEKB factory Tsuyoshi Suwada1,2,*, Muhammad Abdul Rehman1, and Fusashi Miyahara1 1High Energy Accelerator Research Organization (KEK), Accelerator Laboratory, Tsukuba, Ibaraki 305-0801, Japan 2The Graduate University for Advanced Studies (SOKENDAI), School of High Energy Accelerator Science, Tsukuba, Ibaraki 305-0801, Japan *[email protected] ABSTRACT The direct simultaneous detection of electron and positron bunch signals was successfully performed for the first time with wideband pickups and a detection system at the positron capture section of the SuperKEKB factory. The time interval between the electron and positron bunches, their bunch lengths, and bunch intensities depending on the phase of accelerating structures were measured to investigate their capture process and to maximally optimize the positron intensity. The results show that the time intervals were measured in the range of 135–265 ps, and the line-order switch of the electron and positron bunches in the axial direction was clearly observed as a function of the phase. The positron (electron) intensity was maximized at the optimal phase (180 deg shifted from the optimum).
    [Show full text]