Micron-scale laser-wire scanner for the KEK Accelerator Test Facility extraction line

Physical Review Special Topics - Accelerators and Beams 13:12 (2010)

Authors:

ST Boogert, GA Blair, G Boorman, A Bosco, LC Deacon, P Karataev, A Aryshev, M Fukuda, N Terunuma, J Urakawa, L Corner, N Delerue, B Foster, D Howell, M Newman, R Senanayake, R Walczak, F Ganaway

Abstract:

A laser-wire transverse electron beam size measurement system has been constructed and operated at the Accelerator Test Facility (ATF) extraction line at KEK. The construction of the system is described in detail along with the environment of the ATF related to the laser wire. A special set of electron beam optics was developed to generate an approximately 1μm vertical focus at the laser-wire location. The results of our operation at the ATF extraction line are presented, where a minimum rms electron beam size of 4.8±0.3μm was measured, and smaller electron beam sizes can be measured by developing the method further. The beam size at the laser-wire location was changed using quadrupoles and the resulting electron beam size measured, and vertical emittance extracted.© 2010 The American Physical Society.

Inclusive dijet cross sections in neutral current deep inelastic scattering at HERA

European Physical Journal C 70:4 (2010) 965-982

Authors:

H Abramowicz, I Abt, L Adamczyk, M Adamus, R Aggarwal, S Antonelli, P Antonioli, A Antonov, M Arneodo, V Aushev, Y Aushev, O Bachynska, A Bamberger, AN Barakbaev, G Barbagli, G Bari, F Barreiro, D Bartsch, M Basile, O Behnke, J Behr, U Behrens, L Bellagamba, A Bertolin, S Bhadra, M Bindi, C Blohm, V Bokhonov, T Bołd, EG Boos, K Borras, D Boscherini, D Bot, SK Boutle, I Brock, E Brownson, R Brugnera, N Brümmer, A Bruni, G Bruni, B Brzozowska, PJ Bussey, JM Butterworth, B Bylsma, A Caldwell, M Capua, R Carlin, CD Catterall, S Chekanov, J Chwastowski, J Ciborowski, R Ciesielski, L Cifarelli, F Cindolo, A Contin, AM Cooper-Sarkar, N Coppola, M Corradi, F Corriveau, M Costa, G D'Agostini, F Dal Corso, J del Peso, RK Dementiev, S De Pasquale, M Derrick, RCE Devenish, D Dobur, BA Dolgoshein, G Dolinska, AT Doyle, V Drugakov, LS Durkin, S Dusini, Y Eisenberg, PF Ermolov, A Eskreys, S Fang, S Fazio, J Ferrando, MI Ferrero, J Figiel, M Forrest, B Foster, S Fourletov, G Gach, A Galas, E Gallo, A Garfagnini, A Geiser, I Gialas, LK Gladilin, D Gladkov, C Glasman, O Gogota, YA Golubkov, P Göttlicher, I Grabowska-Bołd, J Grebenyuk, I Gregor

Abstract:

Single- and double-differential inclusive dijet cross sections in neutral current deep inelastic ep scattering have been measured with the ZEUS detector using an integrated luminosity of 374 pb-1. The measurement was performed at large values of the photon virtuality, Q2, between 125 and 20 000 GeV2. The jets were reconstructed with the kT cluster algorithm in the Breit reference frame and selected by requiring their transverse energies in the Breit frame, ET,Bjet, to be larger than 8 GeV. In addition, the invariant mass of the dijet system, Mjj, was required to be greater than 20 GeV. The cross sections are described by the predictions of next-to-leading-order QCD. © 2010 The Author(s).

Measurement of high-Q2 charged current deep inelastic scattering cross sections with a longitudinally polarised positron beam at HERA

European Physical Journal C 70:4 (2010) 945-963

Authors:

H Abramowicz, I Abt, L Adamczyk, M Adamus, R Aggarwal, S Antonelli, P Antonioli, A Antonov, M Arneodo, V Aushev, Y Aushev, O Bachynska, A Bamberger, AN Barakbaev, G Barbagli, G Bari, F Barreiro, D Bartsch, M Basile, O Behnke, J Behr, U Behrens, L Bellagamba, A Bertolin, S Bhadra, M Bindi, C Blohm, V Bokhonov, T Bołd, EG Boos, K Borras, D Boscherini, D Bot, SK Boutle, I Brock, E Brownson, R Brugnera, N Brümmer, A Bruni, G Bruni, B Brzozowska, PJ Bussey, JM Butterworth, B Bylsma, A Caldwell, M Capua, R Carlin, CD Catterall, S Chekanov, J Chwastowski, J Ciborowski, R Ciesielski, L Cifarelli, F Cindolo, A Contin, AM Cooper-Sarkar, N Coppola, M Corradi, F Corriveau, M Costa, G D'Agostini, F Dal Corso, J del Peso, RK Dementiev, S De Pasquale, M Derrick, RCE Devenish, D Dobur, BA Dolgoshein, G Dolinska, AT Doyle, V Drugakov, LS Durkin, S Dusini, Y Eisenberg, PF Ermolov, A Eskreys, S Fang, S Fazio, J Ferrando, MI Ferrero, J Figiel, M Forrest, B Foster, S Fourletov, G Gach, A Galas, E Gallo, A Garfagnini, A Geiser, I Gialas, LK Gladilin, D Gladkov, C Glasman, O Gogota, YA Golubkov, P Göttlicher, I Grabowska-Bołd, J Grebenyuk, I Gregor

Abstract:

Measurements of the cross sections for charged current deep inelastic scattering in e+p collisions with a longitudinally polarised positron beam are presented. The measurements are based on a data sample with an integrated luminosity of 132 pb-1 collected with the ZEUS detector at HERA at a centre-of-mass energy of 318 GeV. The total cross section is presented at positive and negative values of the longitudinal polarisation of the positron beams. The single-differential cross-sections dσ/dQ2, dσ/dx and dσ/dy are presented for Q2>200 GeV2. The reduced cross-section σ̃ is presented in the kinematic range 200

All-optical steering of laser-wakefield-accelerated electron beams

Physical Review Letters 105:21 (2010)

Authors:

A Popp, J Vieira, J Osterhoff, Z Major, R Hörlein, M Fuchs, R Weingartner, TP Rowlands-Rees, M Marti, RA Fonseca, SF Martins, LO Silva, SM Hooker, F Krausz, F Grüner, S Karsch

Abstract:

We investigate the influence of a tilted laser-pulse-intensity front on laser-wakefield acceleration. Such asymmetric light pulses may be exploited to obtain control over the electron-bunch-pointing direction and in our case allowed for reproducible electron-beam steering in an all-optical way within an 8 mrad opening window with respect to the initial laser axis. We also discovered evidence of collective electron-betatron oscillations due to off-axis electron injection into the wakefield induced by a pulse-front tilt. These findings are supported by 3D particle-in-cell simulations. © 2010 The American Physical Society.

Micron size laser-wire system at the ATF extraction line, recent results and ATF-II upgrade

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 623:1 (2010) 564-566

Authors:

A Aryshev, GA Blair, ST Boogert, G Boorman, A Bosco, L Corner, L Deacon, N Delerue, B Foster, F Gannaway, H Hayano, D Howell, P Karataev, L Nevay, M Newman, R Senanayake, N Terunuma, J Urakawa, R Walczak

Abstract:

The KEK Accelerator test facility (ATF) extraction line laser-wire system has been upgraded last year allowing the measurement of micron scale transverse size electron beams. The last measurements using the upgraded system from recent operation at the ATF are presented, demonstrating raw measurements of order 3μm RMS. The main component contributions to this measurement are also discussed. © 2010 Elsevier B.V. All rights reserved.