Keyword: polarization
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MOXC02 Improved Lifetime of a High Spin Polarization Superlattice Photocathode electron, cathode, gun, vacuum 31
 
  • L. Cultrera
    BNL, Upton, New York, USA
  
  Funding: Department of Energy under grant DE-SC0012704
Highly spin po­lar­ized elec­tron beams are re­quired for the op­er­a­tion of a wide range of ac­cel­er­a­tors and in­stru­ments. The pro­duc­tion of such elec­trons re­quires the use of Neg­a­tive Elec­tron Affin­ity (NEA) ac­ti­vated GaAs-based cath­odes op­er­ated in pho­to­elec­tron guns. Be­cause of their ex­treme sen­si­tiv­ity to poor vac­uum con­di­tions the degra­da­tion of the pho­toe­mis­sion process is so strong that NEA ac­ti­vated GaAs-based pho­to­cath­odes can only sur­vive in the ex­treme vac­u­ums typ­i­cal of DC gun. State-of-the-art on pho­to­cath­ode tech­nol­ogy for spin po­lar­ized beam pro­duc­tions are sum­ma­rized. Re­cent re­sults on the use of ro­bust NEA coat­ing based on the Cs-Te and Cs-Sb lead­ing to im­proved op­er­a­tional life­time of a high spin po­lar­iza­tion pho­to­cath­ode are re­viewed. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOXC02  
About • paper received ※ 20 May 2021       paper accepted ※ 19 July 2021       issue date ※ 19 August 2021  
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MOPAB014 First High Spin-Flip Efficiency for High Energy Polarized Protons resonance, dipole, proton, experiment 84
 
  • H. Huang, J. Kewisch, C. Liu, A. Marusic, W. Meng, F. Méot, P. Oddo, V. Ptitsyn, V.H. Ranjbar, T. Roser
    BNL, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In order to min­i­mize the sys­tem­atic er­rors for the Rel­a­tivis­tic Heavy Ion Col­lider (RHIC) spin physics ex­per­i­ments, flip­ping the spin of each bunch of pro­tons dur­ing the stores is needed. Ex­per­i­ments done with sin­gle RF mag­net at en­er­gies less than 2 GeV have demon­strated a spin-flip ef­fi­ciency over 99%. At high en­ergy col­lid­ers with Siber­ian snakes, a sin­gle mag­net spin flip­per does not work be­cause of the large spin tune spread and the gen­er­a­tion of mul­ti­ple, over­lap­ping res­o­nances. Over past decade, RHIC spin flip­per de­sign has evolved and a so­phis­ti­cated spin flip­per, con­structed of nine-di­pole mag­nets, was de­vel­oped to flip the spin in RHIC. A spe­cial op­tics choice was also used to make the spin tune spread very small. In re­cent ex­per­i­ment, 97% spin-flip ef­fi­ciency was mea­sured at both 24 and 255 GeV for the first time. The re­sults show that ef­fi­cient spin flip­ping can be achieved at high en­er­gies. 		 
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DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB014  
About • paper received ※ 16 May 2021       paper accepted ※ 08 June 2021       issue date ※ 20 August 2021  
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MOPAB015 Feasibility of Polarized Deuteron Beam in the EIC resonance, solenoid, proton, detector 87
 
  • H. Huang, F. Méot, V. Ptitsyn, V.H. Ranjbar, T. Roser
    BNL, Upton, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The physics pro­gram in the EIC calls for po­lar­ized neu­tron beam at high en­er­gies. The best neu­tron car­ri­ers are 3He nu­clei and deuterons. Both neu­tron car­ries are ex­pected to be used by spin physics pro­gram in the EIC. Due to the small mag­netic mo­ment anom­aly of deuteron par­ti­cles, much higher mag­netic fields are re­quired for spin ro­ta­tion, so full Siber­ian snake is not fea­si­ble. How­ever, the res­o­nance strength is in gen­eral weak and the num­ber of res­o­nances is also small. It is pos­si­ble to deal with in­di­vid­ual res­o­nances with con­ven­tional meth­ods, such as be­ta­tron tune jump for in­trin­sic de­po­lar­iz­ing res­o­nances; and a weak par­tial snakes for im­per­fec­tion res­o­nances. The study shows that ac­cel­er­at­ing po­lar­ized deuteron be­yond 100GeV/n is pos­si­ble in the EIC. 		 
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DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB015  
About • paper received ※ 16 May 2021       paper accepted ※ 28 May 2021       issue date ※ 13 August 2021  
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MOPAB239 Simulation and Optimization of the Spin Coherence Time of Protons in a Prototype EDM Ring quadrupole, storage-ring, dipole, simulation 771
 
  • M. Vitz, A. Lehrach
    FZJ, Jülich, Germany
  • R. Shankar
    INFN-Ferrara, Ferrara, Italy
  
  The mat­ter-an­ti­mat­ter asym­me­try might be un­der­stood by in­ves­ti­gat­ing the EDM (Elec­tric Di­pole Mo­ment) of el­e­men­tary charged par­ti­cles. A per­ma­nent EDM of a sub­atomic par­ti­cle vi­o­lates time-re­ver­sal and par­ity sym­me­try at the same time and would be, with the cur­rently achiev­able ex­per­i­men­tal ac­cu­racy, a strong in­di­ca­tion for physics be­yond the Stan­dard Model. The JEDI-Col­lab­o­ra­tion (Jülich Elec­tric Di­pole mo­ment In­ves­ti­ga­tions) in Jülich is prepar­ing a di­rect EDM mea­sure­ment for pro­tons and deuterons: first at the stor­age ring COSY (COoler SYn­chro­tron) and later at a ded­i­cated stor­age ring. A pro­to­type EDM ring is an in­ter­me­di­ate step be­fore build­ing the final stor­age ring to demon­strate suf­fi­cient beam life­time and SCT (Spin Co­her­ence Time) in a pure elec­tro­sta­tic ring as well as in a stor­age ring with com­bined elec­tric and mag­netic bend­ing el­e­ments. In order to study the ef­fect of E-B-de­flec­tors on the orbit and the spin mo­tion, the soft­ware li­brary Bmad is used. The first re­sults of the op­tics and spin sim­u­la­tions, with a focus on the op­ti­miza­tion of the SCT, to­wards the pro­to­type EDM ring will be dis­cussed.  
poster icon Poster MOPAB239 [0.560 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB239  
About • paper received ※ 17 May 2021       paper accepted ※ 09 June 2021       issue date ※ 23 August 2021  
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TUPAB107 Accelerator and Light Source Research Program at Duke University FEL, storage-ring, undulator, electron 1636
 
  • Y.K. Wu
    FEL/Duke University, Durham, North Carolina, USA
  
  Funding: This work is supported in part by the US DOE grant no. DE-FG02-97ER41033.
The ac­cel­er­a­tor and light source re­search pro­gram at Duke Free-Elec­tron Laser Lab­o­ra­tory (DFELL), TUNL, is fo­cused on the de­vel­op­ment of the stor­age ring based free-elec­tron lasers (FELs) and a state-of-the-art Comp­ton gamma-ray source, the High In­ten­sity Gamma-ray Source (HIGS) dri­ven by the stor­age ring FEL. With a max­i­mum total flux of about 3·1010 gamma/s and a spec­tral flux of more than 1,000 gamma/s/eV around 10 MeV, the HIGS is the world’s high­est-flux Comp­ton gamma-ray source. Op­er­ated in the en­ergy range from 1 to 100 MeV, the HIGS is a pre­mier Comp­ton gamma-ray fa­cil­ity in the world for a va­ri­ety of nu­clear physics re­search pro­grams, both fun­da­men­tal and ap­plied. In this work, we will de­scribe our re­cent light source de­vel­op­ment to en­able the pro­duc­tion of gamma rays in the higher en­ergy range from 100 and 120 MeV. We will also pro­vide a sum­mary of our re­cent ac­cel­er­a­tor physics and FEL physics re­search ac­tiv­i­ties. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB107  
About • paper received ※ 26 May 2021       paper accepted ※ 14 July 2021       issue date ※ 15 August 2021  
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TUPAB122 SASE3 Variable Polarization Project at the European XFEL undulator, vacuum, FEL, electron 1678
 
  • S.K. Karabekyan, S. Abeghyan, M. Bagha-Shanjani, S. Casalbuoni, U. Englisch, G. Geloni, J. Grünert, S. Hauf, C. Holz, D. La Civita, J. Laksman, D. Mamchyk, M.P. Planas, F. Preisskorn, S. Serkez, H. Sinn, A. Violante, G. Wellenreuther, M. Wuenschel, M. Yakopov, C. Youngman
    EuXFEL, Schenefeld, Germany
  • A. Block, W. Decking, N. Golubeva, K. Knebel, T. Ladwig, D.L. Lenz, D. Lipka, R. Mattusch, N. Mildner, E. Negodin, D. Nölle, J. Prenting, F. Saretzki, M. Schlösser, F. Schmidt-Föhre, E. Schneidmiller, D. Thoden, T. Wamsat, S. Wendt, T. Wilksen, T. Wohlenberg, M.V. Yurkov
    DESY, Hamburg, Germany
  • M. Brügger, M. Calvi, S. Danner, R. Ganter, L. Huber, A. Keller, M.S. Schmidt, T. Schmidt
    PSI, Villigen PSI, Switzerland
  • D.E. Kim
    PAL, Pohang, Republic of Korea
  • Y. Li
    IHEP, People’s Republic of China
  
  At the Eu­ro­pean XFEL, two un­du­la­tor sys­tems for hard and one for soft X-rays have been suc­cess­fully put into op­er­a­tion. The SASE3 soft X-ray un­du­la­tor sys­tem gen­er­ates lin­early po­lar­ized ra­di­a­tion in the hor­i­zon­tal plane. One of the re­quire­ments for ex­tend­ing the ra­di­a­tion char­ac­ter­is­tics is the abil­ity to ob­tain dif­fer­ent po­lar­iza­tion modes. These in­clude both right and left cir­cu­lar, el­lip­ti­cal po­lar­iza­tion, or lin­ear po­lar­iza­tion at an ar­bi­trary angle. For this pur­pose, a sys­tem con­sist­ing of four APPLE X he­li­cal un­du­la­tors de­vel­oped at the Paul Scher­rer In­sti­tute (PSI) is used. This paper pre­sents the de­sign pa­ra­me­ters of the SASE3 un­du­la­tor sys­tem after mod­i­fy­ing it with the he­li­cal af­ter­burner. It also de­scribes the meth­ods and the de­sign so­lu­tions dif­fer­ent from those used at PSI. The sta­tus and sched­ule of the pro­ject are in­tro­duced.  
poster icon Poster TUPAB122 [0.553 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB122  
About • paper received ※ 19 May 2021       paper accepted ※ 31 May 2021       issue date ※ 27 August 2021  
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TUPAB275 Enhanced Orthogonal Polarization Component Treatment in COTRI Model for Microbunched Beam Diagnostics bunching, radiation, diagnostics, laser 2113
 
  • D.W. Rule
    Private Address, Silver Spring, USA
  • A.H. Lumpkin
    ANL, Lemont, Illinois, USA
  
  Funding: Work supported by U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
We pre­sent the re­sults of mod­i­fy­ing our co­her­ent op­ti­cal tran­si­tion ra­di­a­tion in­ter­fer­om­e­try (COTRI) model’s treat­ment of the per­pen­dic­u­lar po­lar­iza­tion of OTR, Iperp. Our pre­vi­ous an­a­lytic ap­prox­i­ma­tion for Iperp was for beam di­ver­gences, sy << 1/g, where g is the Lorentz fac­tor and sy is the rms y-com­po­nent of the beam di­ver­gence. We have re­placed our an­a­lyt­i­cal form with a Gauss­ian quad­ra­ture for the con­vo­lu­tion of Iperp with the di­ver­gence in theta-y. This ex­tends the range of di­ver­gences we re­li­ably model to sy > 1/g. Ipar, the par­al­lel po­lar­iza­tion in the model, is un­changed. Iperp is po­lar­ized along the y-axis and is pro­por­tional to the square of the y-com­po­nent of the beam’s ve­loc­ity dis­tri­b­u­tion. We il­lus­trate our re­sults with two cases: 1) beam en­ergy E=1 GeV, OTR wave­length 633 nm, Q=235 pC, mi­crobunch­ing frac­tion, bf=1%, di­ver­gences of 0.1-0.7 mrad, and rms beam sizes 2,10, and 30 mi­crons; 2) E=375 MeV, wave­length 266 nm, Q=300 pC, bf=10%, di­ver­gences of 0.1-0,7 mrad, and rms beam sizes of 10,25,50, and 100 mi­crons. We will pre­sent two cases that would be of in­ter­est for the di­ag­nos­tics of laser-plasma ac­cel­er­a­tor beams* and pre-bunched FELs**, re­spec­tively.
* A. H. Lumpkin et al., Phys. Rev. Lett. 125, 014801 (2020).
** A. H. Lumpkin and D. W. Rule, in Proc., 39th International FEL Conference, FEL 2019 (JACoW Pub., Hamburg, Germany, 2019), pp. 408-411. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB275  
About • paper received ※ 22 May 2021       paper accepted ※ 10 June 2021       issue date ※ 20 August 2021  
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TUPAB373 Design of a Delta-type Superconducting Undulator at the IHEP undulator, photon, permanent-magnet, radiation 2391
 
  • J.H. Wei
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • C.D. Deng
    DNSC, Dongguan, People’s Republic of China
  • L. Gong, X.Y. Li, X.C. Yang
    IHEP, Beijing, People’s Republic of China
  • Y. Li
    DESY, Hamburg, Germany
  
  Un­du­la­tors play an im­por­tant role in the 4th gen­er­a­tion ra­di­a­tion light source. In order to sat­isfy dif­fer­ent re­quire­ments of the ex­per­i­ments, var­i­ous un­du­la­tor struc­tures have been pro­posed. The Delta-type un­du­la­tor can pro­vide cir­cu­lar po­lar­ized ra­di­a­tion. Con­ven­tional un­du­la­tors are usu­ally made of per­ma­nent mag­nets, but the ap­pli­ca­tion of the su­per­con­duct­ing tech­nol­ogy in the un­du­la­tor is de­vel­op­ing quickly. Com­pared to the per­ma­nent mag­net un­du­la­tors, su­per­con­duct­ing un­du­la­tors can pro­vide higher pho­ton flux with the same mag­netic pole gap and pe­riod length, es­pe­cially when the pe­riod length is longer than 20 mm. An R&D pro­ject is un­der­way to pro­duce a protype of a Delta-type su­per­con­duct­ing un­du­la­tor with 28 mm long pe­riod and 12 mm gap at the IHEP. The struc­ture de­sign and the sim­u­la­tion re­sults of the mag­netic field are pre­sented in this paper.  
poster icon Poster TUPAB373 [1.752 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB373  
About • paper received ※ 19 May 2021       paper accepted ※ 18 June 2021       issue date ※ 15 August 2021  
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WEXC05 First Results Operating a Long-Period EPU in Universal Mode at the Canadian Light Source photon, focusing, undulator, injection 2566
 
  • W.A. Wurtz, C.K. Baribeau, D. Bertwistle, M.J. Sigrist
    CLS, Saskatoon, Saskatchewan, Canada
  
  The Quan­tum Ma­te­ri­als Spec­troscopy Cen­tre beam­line at the Cana­dian Light Source (CLS) re­quires pho­tons with en­er­gies as low as 15 eV with cir­cu­lar po­lar­iza­tion at the end sta­tion. This en­ergy range is ac­com­plished on the 2.9 GeV CLS stor­age ring using an el­lip­ti­cally po­lar­iz­ing un­du­la­tor (EPU) with a 180 mm pe­riod, which we call EPU180. In order to re­al­ize cir­cu­lar po­lar­ized pho­tons at the end sta­tion with this low en­ergy, we must over­come two tech­ni­cal is­sues. First, the beam­line op­tics dis­tort the po­lar­iza­tion of the light, so we com­pen­sate by pro­vid­ing light with a flat­tened, tilted po­lar­iza­tion el­lipse at the source point - a mode of op­er­a­tion known as uni­ver­sal mode. Sec­ond, the de­vice has a strong ef­fect on the elec­tron beam due to dy­namic fo­cus­ing and is ca­pa­ble of re­duc­ing the in­jec­tion ef­fi­ciency to zero. We over­come this non-lin­ear dy­namic fo­cus­ing using cur­rent strips ad­hered to the vac­uum cham­ber. In this re­port, we pre­sent the first re­sults with op­er­at­ing EPU180 in uni­ver­sal mode and we re­cover the dy­namic aper­ture using the cur­rent strips.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEXC05  
About • paper received ※ 13 May 2021       paper accepted ※ 05 July 2021       issue date ※ 11 August 2021  
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WEPAB080 Near Threshold Pion Photoproduction on Deuterons photon, experiment, multipole, scattering 2775
 
  • V. Shastri, V. Aswathi, S.P. Shilpashree
    Christ University, School of Engineering and Technology, Bangalore, India
  
  The study of pho­to­pro­duc­tion of mesons is a prime tool in un­der­stand­ing the prop­er­ties of strong in­ter­ac­tions. The only pho­to­pro­duc­tion re­ac­tion on deuteron with two-body final state is co­her­ent pion pho­to­pro­duc­tion re­ac­tion. Sev­eral the­o­ret­i­cal stud­ies are being car­ried out on the pion pho­to­pro­duc­tion on deuterons since sev­eral decades. On the ex­per­i­men­tal side, the ac­cel­er­a­tor and de­tec­tor tech­nol­ogy has im­proved the de­vel­op­ments. In the re­cent years, mea­sure­ments of ten­sor an­a­lyz­ing pow­ers as­so­ci­ated with co­her­ent and in­co­her­ent pion pho­to­pro­duc­tion are also being car­ried out at the VEPP-3 elec­tron stor­age ring. In one of the re­cent mea­sure­ments, Rachek et al"*" have ob­served dis­crep­ancy be­tween the­ory and ex­per­i­ment at higher pho­ton en­er­gies and have sug­gested for im­prove­ment of the the­o­ret­i­cal mod­els. In a more re­cent analy­sis,"**" the role of D-wave com­po­nent on spin asym­me­tries have been iden­ti­fied. In view of these de­vel­op­ments, the pur­pose of the pre­sent con­tri­bu­tion is to study co­her­ent pion pho­to­pro­duc­tion on deuterons using model in­de­pen­dent ir­re­ducible ten­sor for­mal­ism de­vel­oped ear­lier to study the pho­to­dis­in­te­gra­tion of deuterons."***"
*I A Rachek et al., Few-Body Syst., 58, 29 (2017)
**H M Al Ghamdi et al, Brazillian Journal of Physics, 50, 615 (2020)
*** G Ramachandran, S P Shilpashree Phys. Rev. C 74, 052801(R) (2006) 		 
poster icon Poster WEPAB080 [0.203 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB080  
About • paper received ※ 29 May 2021       paper accepted ※ 01 July 2021       issue date ※ 16 August 2021  
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WEPAB102 Half-Metal Spin Filter for Highly Polarized Emission from GaAs Photocathodes electron, cathode, lattice, hardware 2833
 
  • S. Poddar, C.-J. Jing, E.J. Montgomery
    Euclid Beamlabs, Bolingbrook, USA
  • P. Lukashev
    University of Northern Iowa, Cedar Falls, Iowa, USA
  • C. Palmstrøm
    UCSB, Santa Barbara, California, USA
  • M.L. Stutzman, S. Zhang
    JLab, Newport News, Virginia, USA
  
  Funding: Work supported by Department of Energy grant number DE-SC0020564.
GaAs-based pho­to­cath­odes are one of the major sources of spin-po­lar­ized elec­trons and are cru­cial for the up­com­ing Elec­tron-Ion col­lider ex­per­i­ments which in­cludes study of pro­ton spin and spin par­ity vi­o­la­tion in the stan­dard model. The the­o­ret­i­cal po­lar­iza­tion limit in un­strained GaAs pho­to­cath­odes is 50 % but only 35 % is rou­tinely achieved in ex­per­i­ments. Spin se­lec­tive fil­ter­ing al­lows to boost the spin po­lar­iza­tion be­yond the 50 % the­o­ret­i­cal limit. In this work, first-prin­ci­ple elec­tronic cal­cu­la­tions using stan­dard Den­sity Func­tional The­ory are per­formed to pre­dict pos­si­ble Heusler alloy half-metal can­di­dates to be used as spin-fil­ter. Sim­u­la­tions are also per­formed to in­ves­ti­gate the half-metal­lic­ity as func­tion of the mag­netic spin di­rec­tion. Sev­eral de­vices are ex­per­i­men­tally fab­ri­cated using ded­i­cated Mol­e­c­u­lar Beam Epi­taxy growth sys­tem. We im­ple­mented Quan­tum Ef­fi­ciency and Po­lar­iza­tion test­ing of these half-metal/GaAs het­erostruc­tures using a ded­i­cated Mott po­larime­ter sys­tem. Pho­toe­mis­sion can also be seen on mag­net­i­cally switch­ing the spin-fil­ter di­rec­tion ac­com­pa­nied by a change in sign of the asym­me­try which is a qual­i­ta­tive proof of the spin-fil­ter­ing ef­fect. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB102  
About • paper received ※ 20 May 2021       paper accepted ※ 28 July 2021       issue date ※ 27 August 2021  
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WEPAB188 New Method to Search for Axion-Like Particles Demonstrated with Polarized Beam at the COSY Storage Ring resonance, storage-ring, experiment, dipole 3057
 
  • S. Karanth
    Jagiellonian University, Kraków, Poland
  
  The axion was orig­i­nally pro­posed to ex­plain the small size of CP vi­o­la­tion in quan­tum chro­mo­dy­nam­ics. It might be a can­di­date for dark mat­ter in the uni­verse. Ax­ions or ax­ion-like par­ti­cles (ALPs) when cou­pled to glu­ons in­duce an os­cil­lat­ing Elec­tric Di­pole Mo­ment (EDM) along the nu­cleon’s spin di­rec­tion. At the Cooler Syn­chro­tron (COSY) in Jülich, this prin­ci­ple was used to per­form a first test ex­per­i­ment to search for ALPs using an in-plane po­lar­ized deuteron beam. If the spin pre­ces­sion fre­quency equals the EDM os­cil­la­tion fre­quency, a res­o­nance oc­curs that ac­cu­mu­lates the ro­ta­tion of the po­lar­iza­tion out of the ring plane. Since the axion fre­quency is un­known, the beam mo­men­tum was ramped to search for a ver­ti­cal po­lar­iza­tion jump that would occur when the res­o­nance is crossed. At COSY, four beam bunches with dif­fer­ent po­lar­iza­tion di­rec­tions were used to make sure that no res­o­nance was missed be­cause of the un­known rel­a­tive phase be­tween the po­lar­iza­tion pre­ces­sion and the EDM os­cil­la­tions. We scanned a fre­quency win­dow of about a 1-kHz width around the spin pre­ces­sion fre­quency of 121 kHz. This talk will de­scribe the ex­per­i­ment and show pre­lim­i­nary re­sults.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB188  
About • paper received ※ 19 May 2021       paper accepted ※ 01 July 2021       issue date ※ 31 August 2021  
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WEPAB405 Supercontinuum Generation for the Improvement of Pulse Radiolysis System laser, radiation, photon, electron 3657
 
  • M. Sato, Y. Kaneko, Y. Koshiba, M. Washio
    RISE, Tokyo, Japan
  • K. Sakaue
    The University of Tokyo, Graduate School of Engineering, Bunkyo, Japan
  
  Pulse ra­di­ol­y­sis is one of the ab­sorp­tion mea­sure­ment meth­ods for in­ves­ti­gat­ing the fun­da­men­tal, ul­tra­fast process of ra­di­a­tion chem­i­cal re­ac­tions. An­a­lyt­i­cal light is trans­mit­ted si­mul­ta­ne­ously with the tim­ing of elec­tron beam ir­ra­di­a­tion, and its ab­sorp­tion by re­ac­tive species is de­tected. Since the tar­get re­ac­tions arise in pico sec­ond time scale or even shorter, an­a­lyt­i­cal light is re­quired to have such du­ra­tion. Be­sides, so as not to be buried in noise of the ra­di­a­tion source, the op­ti­cal power of the an­a­lyt­i­cal light must be high enough. Fur­ther­more, it is de­sir­able that the an­a­lyt­i­cal light cov­ers vis­i­ble re­gion be­cause im­por­tant ab­sorp­tions caused by ir­ra­di­a­tion prod­ucts such as hy­drated elec­tron, hy­droxyl rad­i­cal, or so exist in the re­gion. We con­sid­ered that the su­per­con­tin­uum light gen­er­ated from an ul­tra­short pulse laser is suit­able as an an­a­lyt­i­cal light be­cause it has all these char­ac­ter­is­tics. In this study, we gen­er­ate the sec­ond har­monic (775 nm) of an er­bium fiber laser (1550 nm) as a seed laser for su­per­con­tin­uum gen­er­a­tion. In this pre­sen­ta­tion, we re­port the cur­rent sit­u­a­tion of our laser sys­tem and prospects.  
poster icon Poster WEPAB405 [0.734 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB405  
About • paper received ※ 18 May 2021       paper accepted ※ 01 September 2021       issue date ※ 20 August 2021  
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THPAB022 Possibilities for Upgrading to Polarized SuperKEKB electron, experiment, lattice, cathode 3799
 
  • Z.J. Liptak, M. Kuriki
    HU/AdSM, Higashi-Hiroshima, Japan
  • J.M. Roney
    Victoria University, Victoria, B.C., Canada
  
  The Su­perKEKB ac­cel­er­a­tor is cur­rently in op­er­a­tion in Tsukuba, Japan, with a planned long shut­down in 2026. Among the pos­si­ble up­grades being con­sid­ered dur­ing this pe­riod is the change to a po­lar­ized elec­tron beam in the High En­ergy Ring. Such a change would re­quire mod­i­fi­ca­tions in the source gen­er­a­tion and trans­port, geo­met­ri­cal and lat­tice vari­a­tions to pro­vide spin ro­ta­tion, and po­larime­try. A Po­lar­ized Su­perKEKB Work­ing Group has been formed from mem­bers of the Belle II ex­per­i­ment and the Su­perKEKB ac­cel­er­a­tor team to in­ves­ti­gate the pos­si­bil­i­ties and chal­lenges of these mod­i­fi­ca­tions. This talk lays out the goals of the pro­posed up­grade, con­sid­ers the nec­es­sary changes to the ex­ist­ing ac­cel­er­a­tor and their fea­si­bil­ity and lays out the physics mo­ti­va­tion be­hind such an ef­fort.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB022  
About • paper received ※ 19 May 2021       paper accepted ※ 23 July 2021       issue date ※ 29 August 2021  
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THPAB123 Pytomic: A Python Tool for Polarized Atomic Beam Tracking simulation, detector, sextupole, target 4002
 
  • J.L. Martinez Marin, W. Armstrong, B.M. Mustapha
    ANL, Lemont, Illinois, USA
  
  Funding: This work was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357 through ANL’s LDRD program.
Py­tomic is a new tool for the sim­u­la­tion and analy­sis of atomic beams through mag­netic sys­tems. It is writ­ten in Python and based on the same fun­da­men­tals as other par­ti­cle track­ing codes but for atomic beams in­stead of charged beams. In this case, the ma­nip­u­la­tion and con­trol of neu­tral atomic beams is via a force due to the spin in­ter­act­ing with a mag­netic field gra­di­ent. An ob­ject-ori­ented tool was de­vel­oped to aid in the de­sign of a beam­line through the ma­nip­u­la­tion of mod­u­lar el­e­ments. The Python lan­guage al­lowed for a smooth im­ple­men­ta­tion and kept the code clear and sim­ple. The pri­mary pur­pose of de­vel­op­ing this code was to have a tool to de­sign, sim­u­late, and op­ti­mize a Breit-Rabi Po­larime­ter to mea­sure the po­lar­iza­tion of an atomic beam. There­fore, dif­fer­ent set-ups with dif­fer­ent mag­nets need to be sim­u­lated and op­ti­mized for di­rect com­par­i­son. In ad­di­tion to sim­u­la­tion and track­ing mod­ules, a new data analy­sis mod­ule was de­vel­oped to be able to quickly an­a­lyze sim­u­la­tion re­sults, gain­ing in­sight from each it­er­a­tion of the sim­u­la­tion, lead­ing to an ef­fi­cient and rapid de­sign process. Ex­am­ple ap­pli­ca­tions to de­sign po­larime­ters for atomic beams will be pre­sented. 		 
poster icon Poster THPAB123 [7.765 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB123  
About • paper received ※ 20 May 2021       paper accepted ※ 21 June 2021       issue date ※ 27 August 2021  
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THPAB131 Spatio-Temporal Measurements of THz Pulses electron, radiation, laser, FEM 4021
 
  • G.A. Hine
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory under Contract No. DEAC05-00OR22725.
The 3D char­ac­ter­i­za­tion of sin­gle-cy­cle Ter­a­hertz (THz) pulses in its trans­verse and tem­po­ral di­men­sions is pre­sented. The high fields and short wave­lengths of THz pulses make them an in­trigu­ing prospect for novel ac­cel­er­a­tor tech­nolo­gies. Ef­fec­tive ap­pli­ca­tion for free-space THz pulses re­quires high beam qual­ity and con­comi­tant mea­sur­ing tech­niques. The com­bi­na­tion of con­ven­tional elec­tro-op­tic sam­pling to mea­sure the tem­po­ral pro­file and de­tec­tors like mi­crobolome­ter focal plane ar­rays to mea­sure the trans­verse pro­file does not cap­ture the cor­re­la­tions that can arise in sin­gle-cy­cle THz pulses. To cap­ture these cor­re­la­tions, a mod­i­fied ver­sion elec­tro-op­tic sam­pling using a CCD is im­ple­mented. THz pulses gen­er­ated by op­ti­cal rec­ti­fi­ca­tion in or­ganic crys­tals are mea­sured using this tech­nique and their spa­tiotem­po­ral cor­re­la­tions char­ac­ter­ized. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB131  
About • paper received ※ 19 May 2021       paper accepted ※ 14 July 2021       issue date ※ 17 August 2021  
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THPAB170 RF Deflector Design for Rapid Proton Therapy proton, cavity, simulation, quadrupole 4086
 
  • E.J.C. Snively, G.B. Bowden, V.A. Dolgashev, Z. Li, E.A. Nanni, D.T. Palmer, S.G. Tantawi
    SLAC, Menlo Park, California, USA
  
  Funding: This work is supported by US Department of Energy Contract No. DE-AC02-76SF00515.
Pen­cil beam scan­ning of charged par­ti­cle beams is a key tech­nol­ogy en­abling high dose rate can­cer ther­apy. The po­ten­tial ben­e­fits of high-speed dose de­liv­ery in­clude not only a re­duc­tion in total treat­ment time and im­prove­ments to mo­tion man­age­ment dur­ing treat­ment but also the pos­si­bil­ity of en­hanced healthy tis­sue spar­ing through the FLASH ef­fect, a promis­ing new treat­ment modal­ity. We pre­sent here the de­sign of an RF de­flec­tor op­er­at­ing at 2.856 GHz for the rapid steer­ing of 150 MeV pro­ton beams. The de­sign uti­lizes a TE11-like mode sup­ported by two posts pro­trud­ing into a pill­box geom­e­try to form an RF di­pole. This con­fig­u­ra­tion pro­vides a sig­nif­i­cant en­hance­ment to the ef­fi­ciency of the struc­ture, char­ac­ter­ized by a trans­verse shunt im­ped­ance of 68 MOhm/m, as com­pared to a con­ven­tional TM11 de­flec­tor. We dis­cuss sim­u­la­tions of the struc­ture per­for­mance for sev­eral op­er­at­ing con­fig­u­ra­tions in­clud­ing the ad­di­tion of a per­ma­nent mag­net quadru­pole to am­plify the RF-dri­ven de­flec­tion. In ad­di­tion to sim­u­la­tion stud­ies, we will pre­sent pre­lim­i­nary re­sults from a 3-cell pro­to­type fab­ri­cated using four cop­per slabs to ac­com­mo­date the non-ax­i­ally sym­met­ric cell geom­e­try. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB170  
About • paper received ※ 19 May 2021       paper accepted ※ 14 July 2021       issue date ※ 27 August 2021  
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THPAB174 T-BMT Spin Resonance Tracker Code for He3 with Six Snakes resonance, emittance, HOM, betatron 4101
 
  • V.H. Ranjbar, H. Huang, Y. Luo, F. Méot, V. Ptitsyn
    BNL, Upton, New York, USA
  • G.H. Hoffstaetter, D. Sagan
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • F. Lin, V.S. Morozov
    JLab, Newport News, Virginia, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy .
Po­lar­iza­tion life­time for He3 using two and six snakes are stud­ied using the T-BMT Spin Res­o­nance Tracker code. This code in­te­grates a re­duced spinor form of the T-BMT equa­tion in­clud­ing only sev­eral spin res­o­nances and the kine­mat­ics of syn­chro­tron mo­tion. It was pre­vi­ously bench­marked against RHIC po­lar­iza­tion life­time under the two snake sys­tem *.
* Phys. Rev.Accel. Beams 22 (2019) 9, 091001 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB174  
About • paper received ※ 20 May 2021       paper accepted ※ 02 July 2021       issue date ※ 28 August 2021  
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THPAB177 Simulation Model Improvements at the Cooler Synchrotron COSY Using the LOCO Algorithm simulation, storage-ring, quadrupole, dipole 4111
 
  • V. Poncza, A. Lehrach
    FZJ, Jülich, Germany
  • A. Lehrach, V. Poncza
    RWTH, Aachen, Germany
  
  Funding: ERC Advanced Grant (srEDM #694340) of the European Union
The JEDI (Jülich Elec­tric Di­pole mo­ment In­ves­ti­ga­tions) col­lab­o­ra­tion is search­ing for Elec­tric Dipol Mo­ments (EDMs) of charged par­ti­cles in stor­age rings. In a step­wise ap­proach, a first di­rect deuteron EDM mea­sure­ment was per­formed at the Cooler Syn­chro­tron COSY and de­sign stud­ies for a ded­i­cated pro­ton EDM stor­age ring are un­der­way. In an ex­per­i­ment with a po­lar­ized beam in a stor­age ring, an EDM leads to a ver­ti­cal po­lar­iza­tion buildup. How­ever, the ver­ti­cal po­lar­iza­tion com­po­nent is also in­duced by sys­tem­atic ef­fects such as mag­net mis­align­ments. To in­ves­ti­gate sys­tem­atic ef­fects in­di­vid­u­ally and to sup­port data analy­sis, a re­al­is­tic sim­u­la­tion model of the stor­age ring is needed. In this paper, the de­vel­op­ment of such a model based on the Bmad soft­ware li­brary is pre­sented. Fur­ther­more, var­i­ous sys­tem­atic ef­fects and their im­pact on the spin mo­tion in COSY are in­ves­ti­gated and quan­ti­fied by means of beam and spin track­ing sim­u­la­tions. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB177  
About • paper received ※ 19 May 2021       paper accepted ※ 27 July 2021       issue date ※ 12 August 2021  
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