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Martin, I.P.S.

Paper Title Page
TUPE054 Short Pulse Options for the UK's New Light Source Project 2266
 
  • I.P.S. Martin
    Diamond, Oxfordshire
  • R. Bartolini, I.P.S. Martin
    JAI, Oxford
  • D.J. Dunning, N. Thompson
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
 
 

The New Light Source pro­ject aims to con­struct a suite of seed­ed free-elec­tron lasers driv­en by a 2.25GeV cw super con­duct­ing linac. As part of the up­grade path, a num­ber of op­tions are being con­sid­ered for gen­er­at­ing ultra short (<1fs) soft x-ray puls­es, with low-charge 'sin­gle-spike' op­er­a­tion and bunch slic­ing like ap­proach­es of par­tic­u­lar in­ter­est, in­clud­ing as a pos­si­ble ex­ten­sion to echo-en­hanced har­mon­ic gen­er­a­tion. In this paper we pre­sent the sta­tus of this work, in­clud­ing re­cent re­sults from fully start to end sim­u­la­tions.

 
WEPEA065 Beam Dynamics for the NLS Superconducting Linac 2633
 
  • R. Bartolini, C. Christou, J.H. Han, I.P.S. Martin, J. Rowland
    Diamond, Oxfordshire
  • D. Angal-Kalinin, D.J. Dunning, F. Jackson, B.D. Muratori, N. Thompson, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
 
 

We pre­sent the progress with the de­sign of the 2.25 GeV su­per­con­duct­ing linac for the NLS pro­ject. We dis­cuss the per­for­mance achieved, the op­ti­mi­sa­tion strate­gies, the rel­e­vance of mi­crobunch­ing in­sta­bil­i­ty and the anal­y­sis of the ef­fect of var­i­ous jit­ter sources

 
WEPEA066 The First Eighteen Months of Top-up at Diamond Light Source 2636
 
  • C. Christou, J.A. Dobbing, R.T. Fielder, I.P.S. Martin, S.J. Singleton
    Diamond, Oxfordshire
 
 

Di­a­mond Light Source has de­liv­ered beam for users ex­clu­sive­ly in top-up mode since the end of Oc­to­ber 2008. In this mode, a small num­ber of sin­gle bunch­es are in­ject­ed into spe­cif­ic buck­ets of the stor­age ring every ten min­utes in order to main­tain a con­stant beam cur­rent and fill pat­tern. Dur­ing top-up the stor­age ring cur­rent is held with­in a win­dow of ap­prox­i­mate­ly 1.5mA around the tar­get cur­rent, gen­er­al­ly 250mA, for a va­ri­ety of fill pat­terns, in­clud­ing a two-thirds stor­age ring fill and a hy­brid fill in which an in­tense sin­gle bunch is added to the nor­mal fill pat­tern. Top-up has run con­tin­u­ous­ly for sev­er­al days on many oc­ca­sions, with in­jec­tion ef­fi­cien­cy into the stor­age ring of typ­i­cal­ly 60%-95% even with 10 in-vac­u­um in­ser­tion de­vice in op­er­a­tion with a per­mit­ted min­i­mum gap of 5 mm. The ef­fect of in­ser­tion de­vices, pulsed mag­net sta­bil­i­ty and stor­age ring beam op­tics on top-up re­li­a­bil­i­ty and per­for­mance is ex­am­ined, and the de­vel­op­ment of tools for the con­trol of top-up and stor­age ring fill is de­tailed.

 
THPE037 Low Alpha Operation of the Diamond Storage Ring 4599
 
  • I.P.S. Martin, G. Rehm, J. Rowland, C.A. Thomas
    Diamond, Oxfordshire
  • R. Bartolini, I.P.S. Martin
    JAI, Oxford
 
 

The Di­a­mond stor­age ring has been op­er­at­ed in low alpha mode pro­vid­ing short-pulse ra­di­a­tion for pump-probe ex­per­i­ments and co­her­ent ra­di­a­tion for THz/IR mea­sure­ments. Two lat­tices have been im­ple­ment­ed, with both ca­pa­ble of pro­vid­ing a vari­able alpha in the range ±2x10-5, down to min­i­mum val­ues well below 1x10-6. The sec­ond lat­tice ad­di­tion­al­ly pro­vides a low emit­tance of 4nm.​rad, com­pared to 35nm.​rad for the first lat­tice. An overview of op­er­a­tion in low alpha mode is given, along with first mea­sure­ments of co­her­ent emis­sion at long wave­lengths under a va­ri­ety of con­di­tions.

 
MOPE081 Performance of a Streak Camera using Reflective Input Optics 1170
 
  • C.A. Thomas, G. Rehm
    Diamond, Oxfordshire
  • I.P.S. Martin
    JAI, Oxford
 
 

Elec­tron bunch pro­file and length mea­sure­ment from large band­width syn­chrotron ra­di­a­tion with a streak cam­era can be strong­ly lim­it­ed by the chirp in­tro­duced by the length of ma­te­ri­al pre­sent in the input re­frac­tive op­tics of streak cam­eras. Elim­i­na­tion of the chirp can be done ei­ther by fil­ter­ing the band­width of the syn­chrotron ra­di­a­tion puls­es, by mea­sur­ing time re­solved spec­tra with the streak cam­era, or by re­plac­ing the front op­tics lens­es by fo­cussing mir­rors. The first so­lu­tion re­duces the power avail­able, thus lim­it­ing mea­sure­ments to min­i­mum bunch cur­rent that can be too high to as­sess the 'zero' cur­rent bunch length. The sec­ond el­e­gant so­lu­tion al­lows mea­sure­ment of the bunch length with the whole band­width and avail­able power but with loss of the sec­ond sweep axis in the cam­era, so that no beam dy­nam­ics can be ob­served. In order to pre­vent any pulse chirp, keep all the avail­able power and ca­pa­bil­i­ty of beam dy­nam­ics ob­ser­va­tion, we de­signed a new input op­tics ex­clu­sive­ly with mir­rors. We pre­sent here our de­sign and the re­sults of the sys­tem with our streak cam­era, mea­sur­ing 2ps bunch in the new Di­a­mond low-al­pha lat­tice.

 
TUPEC035 Design of the Recirculating Linac Option for the UK New Light Source 1799
 
  • P.H. Williams, D.J. Dunning, N. Thompson
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • D. Angal-Kalinin, J.K. Jones, P.H. Williams
    Cockcroft Institute, Warrington, Cheshire
  • R. Bartolini, I.P.S. Martin
    JAI, Oxford
  • J. Rowland
    Diamond, Oxfordshire
 
 

We pre­sent progress in the de­sign of the re­cir­cu­lat­ing linac op­tion for the UK New Light Source. Im­prove­ments in all ac­cel­er­a­tor sec­tions have been made such that the out­put meets the re­quired spec­i­fi­ca­tions to drive the seed­ed NLS FELs. Full start-to-end sim­u­la­tions and tol­er­ance stud­ies are pre­sent­ed to­geth­er with a com­par­i­son to the base­line, sin­gle pass linac de­sign.

 
TUPEC036 Design of Post Linac Beam Transport for the UK New Light Source Project 1802
 
  • D. Angal-Kalinin, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • D. Angal-Kalinin, F. Jackson, S.P. Jamison, J.K. Jones, B.D. Muratori, N. Thompson
    Cockcroft Institute, Warrington, Cheshire
  • R. Bartolini, I.P.S. Martin
    JAI, Oxford
 
 

The de­sign of free elec­tron laser (FEL) driv­er needs care­ful beam trans­port de­sign to pass very short bunch­es through the switch­yard/spread­er to switch the beam to dif­fer­ent FEL lines. The spread­er de­sign which al­lows flex­i­bil­i­ty in op­er­a­tion has been adapt­ed fol­low­ing the LBNL de­sign*. In order to mea­sure the slice prop­er­ties of the bunch­es two beam di­ag­nos­tics lines are pro­posed, a straight one for beam com­mis­sion­ing pur­pos­es and a branch of the spread­er sim­i­lar to the FEL lines to mea­sure the ad­verse ef­fects that may arise due to pass­ing the short bunch­es through the kick­er and sep­tum mag­nets. As a part of ma­chine pro­tec­tion, post linac col­li­ma­tion sys­tem col­li­mates the halo par­ti­cles in trans­verse and en­er­gy planes. The de­sign of the col­li­ma­tion, beam spread­er and beam di­ag­nos­tics lines is dis­cussed.


* Zholents A.A. et al, CBP Tech Note 401, 2009

 
THPE037 Low Alpha Operation of the Diamond Storage Ring 4599
 
  • I.P.S. Martin, G. Rehm, J. Rowland, C.A. Thomas
    Diamond, Oxfordshire
  • R. Bartolini, I.P.S. Martin
    JAI, Oxford
 
 

The Di­a­mond stor­age ring has been op­er­at­ed in low alpha mode pro­vid­ing short-pulse ra­di­a­tion for pump-probe ex­per­i­ments and co­her­ent ra­di­a­tion for THz/IR mea­sure­ments. Two lat­tices have been im­ple­ment­ed, with both ca­pa­ble of pro­vid­ing a vari­able alpha in the range ±2x10-5, down to min­i­mum val­ues well below 1x10-6. The sec­ond lat­tice ad­di­tion­al­ly pro­vides a low emit­tance of 4nm.​rad, com­pared to 35nm.​rad for the first lat­tice. An overview of op­er­a­tion in low alpha mode is given, along with first mea­sure­ments of co­her­ent emis­sion at long wave­lengths under a va­ri­ety of con­di­tions.

 
THPE087 Calibration of the Nonlinear Accelerator Model at Diamond Storage Ring 4728
 
  • R. Bartolini, G. Rehm, J. Rowland
    Diamond, Oxfordshire
  • P. Kuske
    Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin
  • I.P.S. Martin
    JAI, Oxford
  • F. Schmidt
    CERN, Geneva
 
 

The cor­rect im­ple­men­ta­tion of the non­lin­ear ring model is cru­cial to achieve the top per­for­mance of a syn­chrotron light source. Sev­er­al dy­nam­ics quan­ti­ties can be used to com­pare the real ma­chine with the model and even­tu­al­ly to cor­rect the ac­cel­er­a­tor. Most of these meth­ods are based on the anal­y­sis of turn-by-turn data of ex­cit­ed be­ta­tron os­cil­la­tions. We pre­sent the ex­per­i­men­tal re­sults of the cam­paign of mea­sure­ments car­ried out at the Di­a­mond. A com­bi­na­tion of Fre­quen­cy Map Anal­y­sis and res­o­nant driv­ing terms mea­sure­ments has al­lowed a pre­cise cal­i­bra­tion of the non­lin­ear model ca­pa­ble of re­pro­duc­ing and then cor­rect­ing the non­lin­ear beam dy­nam­ics in the stor­age ring.

 
THPE088 Beam Dynamics Effect of Insertion Devices at Diamond Storage Ring 4731
 
  • B. Singh, R.T. Fielder, J. Rowland
    Diamond, Oxfordshire
  • R. Bartolini, I.P.S. Martin
    JAI, Oxford
 
 

Di­a­mond op­er­ates with 10 in-vac­u­um in­ser­tion de­vices at 5 mm gap, two Ap­ple-II, two su­per­con­duct­ing and two nor­mal con­duct­ing wig­glers. We re­port here the cor­rec­tion of the lin­ear op­tics of wig­glers and mea­sure­ments of non­lin­ear ef­fects such as dy­nam­ic aper­ture and fre­quen­cy maps and their im­pacts on in­jec­tion ef­fi­cien­cy, life­time and loss dis­tri­bu­tion in op­er­a­tion of the stor­age ring.