[FFA_CEBAF_Collab] [EXTERNAL] Re: FFA corrector concept
Berg, J Scott
jsberg at bnl.gov
Mon Aug 29 09:47:08 EDT 2022
I think we should at least have frames and coils sufficient to do everything on each FFA magnet; we can then power as needed, and power supplies are a usually a big chunk of the cost anyhow (though the coils are probably nontrivial as well). If you don't have the coils and decide you want them later, that becomes a much bigger deal.
In the discussion of the saturation field, is there any reason not to be generous with the iron thickness? We're not talking about a lot of iron here, and the coil length per turn should be dominated by the longitudinal length. I was a bit confused, there were numbers at 1.4 T and later 1.0 T was given.
-Scott
> -----Original Message-----
> From: FFA_CEBAF_Collab <ffa_cebaf_collab-bounces at jlab.org> On Behalf Of Jay
> Benesch via FFA_CEBAF_Collab
> Sent: Tuesday, August 23, 2022 1:27 PM
> To: Alex Bogacz <bogacz at jlab.org>; Brooks, Stephen <sbrooks at bnl.gov>
> Cc: Omar Garza <garza at jlab.org>; Camille Ginsburg <ginsburg at jlab.org>;
> ffa_cebaf_collab at jlab.org; Joseph Meyers <meyers at jlab.org>; Mike Bevins
> <mbevins at jlab.org>; Will Oren <oren at jlab.org>; Chase Dubbe
> <cdubbe at jlab.org>
> Subject: Re: [FFA_CEBAF_Collab] [EXTERNAL] Re: FFA corrector concept
>
> Alex,
>
> One per magnet is NOT conservative. Read the first page of my TN again:
> Stephen's specs. And his email. Three per magnet, two dipole and one
> quad, is conservative. Plus six per cell in each splitter. I assumed
> five cells in each of six splitters at each end of each arc, plus 90
> cells in the arc, to arrive at 300 frames and 900 power supplies per
> arc. That is the upper bound and therefore conservative. Recall the
> lesson of the CDG's SSC estimate and its fate.
>
> Jay
>
> On 8/23/22 13:19, Alex Bogacz wrote:
> > Hi Stephen,
> >
> > I will adjust number of correctors (for costing) to one per magnet, to
> > stay on a conservative site.
> > We can relax it later based on the outcome of the MC simulation.
> >
> > Cheers,
> >
> > Alex
> >
> > ___________________________________
> >
> > S. Alex Bogacz,
> >
> > Accelerator Physics Group Leader
> >
> > Center for Advanced Studies of Accelerators
> >
> > Jefferson Lab
> >
> > 12000 Jefferson Avenue, <x-apple-data-detectors://8>
> >
> > Newport News, VA 23606 <x-apple-data-detectors://8>
> >
> > ___________________________________
> > Sent from my iPhone
> >
> >> On Aug 23, 2022, at 1:10 PM, Brooks, Stephen via FFA_CEBAF_Collab
> >> <ffa_cebaf_collab at jlab.org> wrote:
> >>
> >> It *may* be possible to use fewer, but only after running error
> >> simulations. And typically, using fewer correctors means they have to
> >> be proportionately stronger each.
> >>
> >> So it's better to think of a large number of channels but relatively
> >> low-power power supplies. Vendors can put several of these in a
> >> chassis in some cases. Digital control means there shouldn't be an
> >> enormous penalty for additional channels if the power stays the same,
> >> although we will have to run more cables.
> >>
> >> -Stephen
> >>
> >> ________________________________________
> >> From: Jay Benesch <benesch at jlab.org>
> >> Sent: 23 August 2022 12:09
> >> To: Chase Dubbe; Omar Garza; Joseph Meyers; Will Oren; Mike Bevins
> >> Cc: ffa_cebaf_collab at jlab.org; Camille Ginsburg; Brooks, Stephen
> >> Subject: Re: [FFA_CEBAF_Collab] [EXTERNAL] Re: FFA corrector concept
> >>
> >> Colleauges,
> >>
> >> In case it wasn't clear: Stephen's response below implies that every
> >> window frame needs three power supplies, two for the dipoles and one for
> >> the quad. Including splitters, perhaps 900 power supplies per arc.
> >> Larger service buildings.
> >>
> >> Jay
> >>
> >> On 8/23/22 11:40, Brooks, Stephen wrote:
> >>> If you have multiple energy beams in the same line, you need more
> >>> correctors than for a single energy because you are correcting more
> >>> "degrees of freedom". You can't wait for several cells and cancel an
> >>> error downstream in a simplistic way because the beams undergo
> >>> different phase advances. You'd have to use a complicated set of
> >>> many correctors over several cells to do it.
> >>>
> >>> In particular, a dipole X and Y corrector on every magnet ensures all
> >>> survey errors in the magnet centres can be cancelled out. These
> >>> placement errors are amplified by the fact the gradients are fairly
> >>> high in the FFA.
> >>>
> >>> In CBETA we had half this number: dipole X correctors on the F
> >>> magnets and Y correctors on the D magnets and still could achieve
> >>> reasonable, although not perfect, results with 4 beams. So, every
> >>> magnet in CBETA had an iron frame but only 2 sides had copper coils.
> >>>
> >>> -Stephen
> >>>
> >>> ________________________________________
> >>> From: Alex Bogacz <bogacz at jlab.org>
> >>> Sent: 23 August 2022 10:59
> >>> To: Brooks, Stephen
> >>> Cc: Chase Dubbe; Omar Garza; ffa_cebaf_collab at jlab.org; Jay Benesch;
> >>> Joseph Meyers; Will Oren; Mike Bevins; Camille Ginsburg
> >>> Subject: Re: [FFA_CEBAF_Collab] [EXTERNAL] Re: FFA corrector concept
> >>>
> >>> Hi Stephen,
> >>>
> >>> That initial number came from me; a corrector every other cell….which
> >>> you feel is too sparse. How about one corrector per cell? I think we
> >>> need more thorough study, perhaps a MC simulation to quantify.
> >>> We will further tackle it on Friday…Feel free to lead the discussion…
> >>> Thanks.
> >>>
> >>> Cheers,
> >>>
> >>> Alex
> >>> ___________________________________
> >>> S. Alex Bogacz,
> >>> Accelerator Physics Group Leader
> >>> Center for Advanced Studies of Accelerators
> >>> Jefferson Lab
> >>> 12000 Jefferson Avenue,<x-apple-data-detectors://8>
> >>> Newport News, VA 23606<x-apple-data-detectors://8>
> >>> ___________________________________
> >>> Sent from my iPhone
> >>>
> >>> On Aug 23, 2022, at 10:40 AM, Brooks, Stephen via FFA_CEBAF_Collab
> >>> <ffa_cebaf_collab at jlab.org> wrote:
> >>>
> >>> 100 cells per 180 degree FFA arc would be 200 magnets, and 200
> >>> correctors. So for all FFA sections in the facility (two 180 degree
> >>> arcs), 400 permanent magnets and 400 correctors.
> >>>
> >>> I think what Jay is saying makes sense too. Not sure where "50" came
> >>> from.
> >>>
> >>> -Stephen
> >>>
> >>> ________________________________________
> >>> From: FFA_CEBAF_Collab <ffa_cebaf_collab-bounces at jlab.org> on behalf
> >>> of Jay Benesch via FFA_CEBAF_Collab <ffa_cebaf_collab at jlab.org>
> >>> Sent: 22 August 2022 11:42
> >>> To: Chase Dubbe; Omar Garza; ffa_cebaf_collab at jlab.org
> >>> Cc: Joseph Meyers; Mike Bevins; Will Oren; Camille Ginsburg
> >>> Subject: Re: [FFA_CEBAF_Collab] FFA corrector concept
> >>>
> >>> Chase,
> >>>
> >>> If there are only 50 BD and 50 BF per arc, then 100 assemblies per
> >>> arc. Since the length of the BD+BF cell is about 125 cm, the arc
> >>> circumference is ~250 m and the packing fraction is about 90%, I
> >>> rounded up to 100 cells. I remember 88 and 90 cells per arc
> >>> mentioned in weekly meetings. The splitters will need correctors as
> >>> well and there are at least five cells in each of those. Since the
> >>> splitters are individual lines by definition and there are six at
> >>> each end of each arc in the present concept, add 2*6*5 to the number
> >>> needed, for 150 total per arc. Alex's MMV.
> >>>
> >>> Jay
> >>>
> >>> ________________________________________
> >>> From: Chase Dubbe <cdubbe at jlab.org>
> >>> Sent: Monday, August 22, 2022 11:15 AM
> >>> To: Omar Garza; Jay Benesch; ffa_cebaf_collab at jlab.org
> >>> Cc: Will Oren; Camille Ginsburg; Mike Bevins; Joseph Meyers; Alex
> Bogacz
> >>> Subject: Re: FFA corrector concept
> >>>
> >>> Good Morning Omar,
> >>>
> >>> To try to help, the FFA permanent magnets won't have a power
> >>> requirement, but the Panofsky Quads that will be mounted along with
> >>> them will. Based on the latest Magnet count sheet, there will be 50
> >>> of them per ARC (East/West) and reviewing Jay's technical write up,
> >>> they should need 900W per magnet. He did mention that each would
> >>> require two power supplies.
> >>>
> >>> With regards to the counts though, there is some discrepancy. Jay,
> >>> for each of the ARCs, is the number 50 or 100? Looking at your paper,
> >>> vs the magnet count sheet, you are specifying 100 per ARC vs. the 50.
> >>> Also, do my assumptions on power and power supply requirements line
> >>> up with your specification?
> >>>
> >>> [cid:e6d9ef9a-552c-471e-b389-b9c5801d6a03]
> >>> *Snap shot from Jay's paper 'FFA Corrector Concept'
> >>>
> >>> Name L[cm] B[kG] G[kG/cm] Number of magnets
> >>> BD 50 3.1 4.7 200
> >>> BF 50 5.5 1.5 200
> >>> Panofsky window quad, per Jay's sprec 100
> >>> *Cells Taken from 'New Magnet and RF Inventory' Excel
> >>>
> >>> Thanks,
> >>> Chase
> >>> ________________________________
> >>> From: Omar Garza <garza at jlab.org>
> >>> Sent: Monday, August 22, 2022 10:51 AM
> >>> To: Jay Benesch <benesch at jlab.org>; Chase Dubbe <cdubbe at jlab.org>;
> >>> ffa_cebaf_collab at jlab.org <ffa_cebaf_collab at jlab.org>
> >>> Cc: Will Oren <oren at jlab.org>; Camille Ginsburg <ginsburg at jlab.org>;
> >>> Mike Bevins <mbevins at jlab.org>; Joseph Meyers <meyers at jlab.org>; Alex
> >>> Bogacz <bogacz at jlab.org>
> >>> Subject: Re: FFA corrector concept
> >>>
> >>> Good morning everyone.
> >>> Does someone have the power requirements for the FFAs and new dipoles?
> >>> Thank you.
> >>> O'
> >>>
> >>> Omar Garza
> >>> Deputy of Electrical Engineering Systems - Accelerator Reliability
> >>> Thomas Jefferson National Accelerator Facility
> >>> (757) 269-7257 garza at jlab.org<mailto:garza at jlab.org>
> >>> ________________________________
> >>> From: Jay Benesch <benesch at jlab.org>
> >>> Sent: Monday, August 8, 2022 11:41 AM
> >>> To: Chase Dubbe <cdubbe at jlab.org>; ffa_cebaf_collab at jlab.org
> >>> <ffa_cebaf_collab at jlab.org>
> >>> Cc: Will Oren <oren at jlab.org>; Omar Garza <garza at jlab.org>; Camille
> >>> Ginsburg <ginsburg at jlab.org>; Mike Bevins <mbevins at jlab.org>; Joseph
> >>> Meyers <meyers at jlab.org>; Alex Bogacz <bogacz at jlab.org>
> >>> Subject: Re: FFA corrector concept
> >>>
> >>> Chase,
> >>>
> >>> It is my understanding that each of the permanent magnets will require
> >>> one of these correctors. Only two of the three windings per assembly
> >>> will likely be powered. Hence the estimate of 400 units and 800 power
> >>> supplies. It seems to me better to build all the units with the three
> >>> windings and power only two, to simplify fabrication and assembly. And
> >>> we might need three in some locations. Rabbet joints assumed in the
> >>> steel to simplify assembly.
> >>>
> >>> I'll send you the opc file for this under separate email.
> >>>
> >>> Jay
> >>>
> >>> On 8/8/22 11:27, Chase Dubbe wrote:
> >>> Good Morning Jay,
> >>>
> >>> First, thank you for sharing all the other panofsky quad models. I have
> >>> been out on vacation, so have not had a chance to look through them,
> but
> >>> they are greatly appreciated.
> >>>
> >>> I am still trying to catch up, but for the cost estimate of these
> >>> Picture Frame Correctors, is the intent to have one per each FODO set
> of
> >>> permanent magnets in the FFA line, or will there be more or less? I
> just
> >>> want to get a grasp at the quantity so that I can either use the cost
> >>> estimate numbers Tommy Hiatt had developed, or perhaps go out for an
> RFI
> >>> for cost.
> >>>
> >>> Thanks again for the help,
> >>> Chase Dubbe'
> >>> -----------------------------------------------------------------------
> -
> >>> *From:* Jay Benesch <benesch at jlab.org>
> >>> *Sent:* Monday, August 8, 2022 10:18 AM
> >>> *To:* ffa_cebaf_collab at jlab.org <ffa_cebaf_collab at jlab.org>
> >>> *Cc:* Chase Dubbe <cdubbe at jlab.org>; Will Oren <oren at jlab.org>; Omar
> >>> Garza <garza at jlab.org>; Camille Ginsburg <ginsburg at jlab.org>
> >>> *Subject:* FFA corrector concept
> >>> Attached please find a "picture frame" corrector concept which
> satisfies
> >>> the requirements Stephen provided Friday. It should suffice for the
> cost
> >>> estimate. Comments welcome.
> >>>
> >>>
> >>> _______________________________________________
> >>> FFA_CEBAF_Collab mailing list
> >>> FFA_CEBAF_Collab at jlab.org
> >>> https://mailman.jlab.org/mailman/listinfo/ffa_cebaf_collab
> >> On 8/23/22 11:40, Brooks, Stephen wrote:
> >>> If you have multiple energy beams in the same line, you need more
> >>> correctors than for a single energy because you are correcting more
> >>> "degrees of freedom". You can't wait for several cells and cancel an
> >>> error downstream in a simplistic way because the beams undergo
> >>> different phase advances. You'd have to use a complicated set of
> >>> many correctors over several cells to do it.
> >>>
> >>> In particular, a dipole X and Y corrector on every magnet ensures all
> >>> survey errors in the magnet centres can be cancelled out. These
> >>> placement errors are amplified by the fact the gradients are fairly
> >>> high in the FFA.
> >>>
> >>> In CBETA we had half this number: dipole X correctors on the F
> >>> magnets and Y correctors on the D magnets and still could achieve
> >>> reasonable, although not perfect, results with 4 beams. So, every
> >>> magnet in CBETA had an iron frame but only 2 sides had copper coils.
> >>>
> >>> -Stephen
> >>>
> >>> ________________________________________
> >>> From: Alex Bogacz <bogacz at jlab.org>
> >>> Sent: 23 August 2022 10:59
> >>> To: Brooks, Stephen
> >>> Cc: Chase Dubbe; Omar Garza; ffa_cebaf_collab at jlab.org; Jay Benesch;
> >>> Joseph Meyers; Will Oren; Mike Bevins; Camille Ginsburg
> >>> Subject: Re: [FFA_CEBAF_Collab] [EXTERNAL] Re: FFA corrector concept
> >>>
> >>> Hi Stephen,
> >>>
> >>> That initial number came from me; a corrector every other cell….which
> >>> you feel is too sparse. How about one corrector per cell? I think we
> >>> need more thorough study, perhaps a MC simulation to quantify.
> >>> We will further tackle it on Friday…Feel free to lead the discussion…
> >>> Thanks.
> >>>
> >>> Cheers,
> >>>
> >>> Alex
> >>> ___________________________________
> >>> S. Alex Bogacz,
> >>> Accelerator Physics Group Leader
> >>> Center for Advanced Studies of Accelerators
> >>> Jefferson Lab
> >>> 12000 Jefferson Avenue,<x-apple-data-detectors://8>
> >>> Newport News, VA 23606<x-apple-data-detectors://8>
> >>> ___________________________________
> >>> Sent from my iPhone
> >>>
> >>> On Aug 23, 2022, at 10:40 AM, Brooks, Stephen via FFA_CEBAF_Collab
> >>> <ffa_cebaf_collab at jlab.org> wrote:
> >>>
> >>> 100 cells per 180 degree FFA arc would be 200 magnets, and 200
> >>> correctors. So for all FFA sections in the facility (two 180 degree
> >>> arcs), 400 permanent magnets and 400 correctors.
> >>>
> >>> I think what Jay is saying makes sense too. Not sure where "50" came
> >>> from.
> >>>
> >>> -Stephen
> >>>
> >>> ________________________________________
> >>> From: FFA_CEBAF_Collab <ffa_cebaf_collab-bounces at jlab.org> on behalf
> >>> of Jay Benesch via FFA_CEBAF_Collab <ffa_cebaf_collab at jlab.org>
> >>> Sent: 22 August 2022 11:42
> >>> To: Chase Dubbe; Omar Garza; ffa_cebaf_collab at jlab.org
> >>> Cc: Joseph Meyers; Mike Bevins; Will Oren; Camille Ginsburg
> >>> Subject: Re: [FFA_CEBAF_Collab] FFA corrector concept
> >>>
> >>> Chase,
> >>>
> >>> If there are only 50 BD and 50 BF per arc, then 100 assemblies per
> >>> arc. Since the length of the BD+BF cell is about 125 cm, the arc
> >>> circumference is ~250 m and the packing fraction is about 90%, I
> >>> rounded up to 100 cells. I remember 88 and 90 cells per arc
> >>> mentioned in weekly meetings. The splitters will need correctors as
> >>> well and there are at least five cells in each of those. Since the
> >>> splitters are individual lines by definition and there are six at
> >>> each end of each arc in the present concept, add 2*6*5 to the number
> >>> needed, for 150 total per arc. Alex's MMV.
> >>>
> >>> Jay
> >>>
> >>> ________________________________________
> >>> From: Chase Dubbe <cdubbe at jlab.org>
> >>> Sent: Monday, August 22, 2022 11:15 AM
> >>> To: Omar Garza; Jay Benesch; ffa_cebaf_collab at jlab.org
> >>> Cc: Will Oren; Camille Ginsburg; Mike Bevins; Joseph Meyers; Alex
> Bogacz
> >>> Subject: Re: FFA corrector concept
> >>>
> >>> Good Morning Omar,
> >>>
> >>> To try to help, the FFA permanent magnets won't have a power
> >>> requirement, but the Panofsky Quads that will be mounted along with
> >>> them will. Based on the latest Magnet count sheet, there will be 50
> >>> of them per ARC (East/West) and reviewing Jay's technical write up,
> >>> they should need 900W per magnet. He did mention that each would
> >>> require two power supplies.
> >>>
> >>> With regards to the counts though, there is some discrepancy. Jay,
> >>> for each of the ARCs, is the number 50 or 100? Looking at your paper,
> >>> vs the magnet count sheet, you are specifying 100 per ARC vs. the 50.
> >>> Also, do my assumptions on power and power supply requirements line
> >>> up with your specification?
> >>>
> >>> [cid:e6d9ef9a-552c-471e-b389-b9c5801d6a03]
> >>> *Snap shot from Jay's paper 'FFA Corrector Concept'
> >>>
> >>> Name L[cm] B[kG] G[kG/cm] Number of magnets
> >>> BD 50 3.1 4.7 200
> >>> BF 50 5.5 1.5 200
> >>> Panofsky window quad, per Jay's sprec 100
> >>> *Cells Taken from 'New Magnet and RF Inventory' Excel
> >>>
> >>> Thanks,
> >>> Chase
> >>> ________________________________
> >>> From: Omar Garza <garza at jlab.org>
> >>> Sent: Monday, August 22, 2022 10:51 AM
> >>> To: Jay Benesch <benesch at jlab.org>; Chase Dubbe <cdubbe at jlab.org>;
> >>> ffa_cebaf_collab at jlab.org <ffa_cebaf_collab at jlab.org>
> >>> Cc: Will Oren <oren at jlab.org>; Camille Ginsburg <ginsburg at jlab.org>;
> >>> Mike Bevins <mbevins at jlab.org>; Joseph Meyers <meyers at jlab.org>; Alex
> >>> Bogacz <bogacz at jlab.org>
> >>> Subject: Re: FFA corrector concept
> >>>
> >>> Good morning everyone.
> >>> Does someone have the power requirements for the FFAs and new dipoles?
> >>> Thank you.
> >>> O'
> >>>
> >>> Omar Garza
> >>> Deputy of Electrical Engineering Systems - Accelerator Reliability
> >>> Thomas Jefferson National Accelerator Facility
> >>> (757) 269-7257 garza at jlab.org<mailto:garza at jlab.org>
> >>> ________________________________
> >>> From: Jay Benesch <benesch at jlab.org>
> >>> Sent: Monday, August 8, 2022 11:41 AM
> >>> To: Chase Dubbe <cdubbe at jlab.org>; ffa_cebaf_collab at jlab.org
> >>> <ffa_cebaf_collab at jlab.org>
> >>> Cc: Will Oren <oren at jlab.org>; Omar Garza <garza at jlab.org>; Camille
> >>> Ginsburg <ginsburg at jlab.org>; Mike Bevins <mbevins at jlab.org>; Joseph
> >>> Meyers <meyers at jlab.org>; Alex Bogacz <bogacz at jlab.org>
> >>> Subject: Re: FFA corrector concept
> >>>
> >>> Chase,
> >>>
> >>> It is my understanding that each of the permanent magnets will require
> >>> one of these correctors. Only two of the three windings per assembly
> >>> will likely be powered. Hence the estimate of 400 units and 800 power
> >>> supplies. It seems to me better to build all the units with the three
> >>> windings and power only two, to simplify fabrication and assembly. And
> >>> we might need three in some locations. Rabbet joints assumed in the
> >>> steel to simplify assembly.
> >>>
> >>> I'll send you the opc file for this under separate email.
> >>>
> >>> Jay
> >>>
> >>> On 8/8/22 11:27, Chase Dubbe wrote:
> >>> Good Morning Jay,
> >>>
> >>> First, thank you for sharing all the other panofsky quad models. I have
> >>> been out on vacation, so have not had a chance to look through them,
> but
> >>> they are greatly appreciated.
> >>>
> >>> I am still trying to catch up, but for the cost estimate of these
> >>> Picture Frame Correctors, is the intent to have one per each FODO set
> of
> >>> permanent magnets in the FFA line, or will there be more or less? I
> just
> >>> want to get a grasp at the quantity so that I can either use the cost
> >>> estimate numbers Tommy Hiatt had developed, or perhaps go out for an
> RFI
> >>> for cost.
> >>>
> >>> Thanks again for the help,
> >>> Chase Dubbe'
> >>> -----------------------------------------------------------------------
> -
> >>> *From:* Jay Benesch <benesch at jlab.org>
> >>> *Sent:* Monday, August 8, 2022 10:18 AM
> >>> *To:* ffa_cebaf_collab at jlab.org <ffa_cebaf_collab at jlab.org>
> >>> *Cc:* Chase Dubbe <cdubbe at jlab.org>; Will Oren <oren at jlab.org>; Omar
> >>> Garza <garza at jlab.org>; Camille Ginsburg <ginsburg at jlab.org>
> >>> *Subject:* FFA corrector concept
> >>> Attached please find a "picture frame" corrector concept which
> satisfies
> >>> the requirements Stephen provided Friday. It should suffice for the
> cost
> >>> estimate. Comments welcome.
> >>>
> >>>
> >>> _______________________________________________
> >>> FFA_CEBAF_Collab mailing list
> >>> FFA_CEBAF_Collab at jlab.org
> >>> https://mailman.jlab.org/mailman/listinfo/ffa_cebaf_collab
> >>
> >>
> >>
> >> _______________________________________________
> >> FFA_CEBAF_Collab mailing list
> >> FFA_CEBAF_Collab at jlab.org
> >> https://mailman.jlab.org/mailman/listinfo/ffa_cebaf_collab
>
>
> _______________________________________________
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> FFA_CEBAF_Collab at jlab.org
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