E-rhic-ir-l mailing list

["Christie, William" <christie AT bnl.gov>]

Dear All,
        Below please find the minutes from our eRHIC IR Design meeting that 
was held on Friday, 1/4/2019. Please note that it was decided that our next 
meeting will be this Friday, January 11th, starting at 2:30 pm.
        Greetings,
            Bill

      Minutes from the eRHIC IR Design meeting held on 1/4/19
     
---------------------------------------------------------------------------------
* We started with a brief discussion of the agenda for the meeting.
   - Discussion concerning the status of Bob's IR Design (as detailed in his 
E-mail to the mailing list on December 14, 2018).
   - A look at, and discussion of, Doug's integration slides which he sent to 
Bill on January 4, 2019.
   - A run through of Gary's draft slides for the IR presentation at the 
upcoming internal eRHIC Cost review.
   - AOB

* Discussion concerning Bob's latest design (files: 121418-IR-v2.txt & 
12_14_18-ir-v3.pdf, attached):
   - The overall goal is to get to a "complete" and stable updated (increased 
crossing angle and interaction point translation) IR design. Once stable, 
physics performance simulations can be setup and carried out, as well as 
further refinement of costing and component design.
    - It has been stable since mid December, though as noted below there were 
some recent changes.
    - Steve T. has not yet matched this latest design into the electron ring.
      - Ferdi suggests that one can do a fairly quick look, in sufficient 
detail to determine whether a matching solution is possible.
         - Steve will try to do this.
    - Elke brings up the additional need to reach a stable design so that one 
can do a beam background study, with more design parameters stable/fixed.
    - Holger brings up the concern that some of the magnet parameters in the 
files Bob sent out in December may not be realizable. There were a few 
magnets that Bob changed in his latest iteration that concern Holger and 
Brett. New motivation for the change to these magnet parameters is not by 
anyone in attendance at the meeting. Holger and Brett have sent an E-mail to 
Bob concerning these changes, but as of the time of this meeting haven't 
gotten a reply.
    - In an effort to move forward in the goal of getting to a stable and 
feasible new/updated IR design it is decided that we'll have our next meeting 
in one weeks time (i.e. on Friday January 11th) when Bob is expected to be at 
BNL. Bill will get the minutes out for this meeting, and get a notification 
sent out for the January 11th meeting.

* Walk through and discussion of Doug's Integration slides (file 6IR Layout 
Development Update 2019-01-02.pptx, attached):
   - Doug walks the group through his slides, with many comments and 
questions from the group.
   - Hadron beam is in the Yellow ring
   - Brett points out that the hadron ring Quad magnets shown downstream from 
the crab cavities are assumed to be "reused" Quads from the RHIC Blue ring, 
and hence are assumed to come at zero cost.
   - Slide #2, Doug comments that the B0 coils are superconducting in his 
model.
   - Slide #3, Hadrons traveling to the lower right in the figure. Clear by 
noticing the larger beam pipe.
   - Slide #4, Same comment about the assumption that the Quads shown for the 
Hadron ring are assumed to be "recycled" from the Blue RHIC ring, and hence 
assumed to have zero cost.
   - Flip through the rest of the slides.
   - Point made that it would be nice to see a slide or two of the overall 
layout that includes the RCS ring.

* We walk through Gary's Slides (I don't have a copy of these slides to 
attach).
   - Gary led us through his draft slides, and various comments and 
suggestions were made.

* Next meeting to be on Friday, January 11th, starting at the usual 2:30 pm
    DRAFT AGENDA:
     - Discussion of Bob's December IR Design layout and parameters, assumed 
led by Bob
     - Update by Steve T. on his effort to determine if an Electron ring 
Match solution is possible.
     - Update from Guillaume on his updates and insights on matching the IR 
design into the Hadron rings.
     - AOB
                        End of meeting.

# "gm emit" is a geometric emittance.
#
# "rad1" is the minimum inside magnet aperture at the IP end of magnets.
#
# For straight magnets, "rad2" is given as 0
#
# For tapered magnets "rad2" is the larger aperture father from the IP.
#
# "center-x", "center-y", "center-z" are the horizontal, vertical and 
distance along
# the beam, of the magnet centres, with respect to a Z axis passing through 
the IP
# parallel with the hadron beam at the IP. x=y=z=0 is at the IP. 
#
# "angle" is the horizontal angle between the magnet axis and the Z axis
#
# 
-----------------------------------------------------------------------------
# zpF3513g  Hadron forward  275 
#
# beta*_x  beta*_y  gm emit_x gm emit_y  crossing_x  crossing_y    mom
#  [m]      [m]        [nm]     [nm]      [mrad]      [mrad]     GeV/c
 0.9000   0.0430     20.0000    6.1000      25          0         275  
#
# name    center_z center_x center_y rad1  rad2   length   angle      B      
gradient 
#           [m]      [m]      [m]    [m]    [m]    [m]    [mrad]     [T]     
[T/m]  
  B0pF    5.900  -0.0150    0.00    0.1700   0   1.200   -25.00   -1.300      
0.000  
  Q1ApF    7.730   0.0067    0.00   0.0450   0   1.460    -3.15    0.000    
-77.903  
  Q1BpF    9.565   0.0119    0.00   0.0650   0   1.610   -10.00    0.000    
-63.028  
  Q2pF   13.070   0.0120    0.00    0.1130   0   3.600    -8.89    0.000     
39.736  
  B1pF   16.870   0.0180    0.00    0.1150   0   3.000    10.00   -4.570      
0.000  
# 
-----------------------------------------------------------------------------
# -------------------------------------
# zeF3513d1  Electron forward High beta 
#
# beta*_x  beta*_y  gm emit_x gm emit_y  crossing_x  crossing_y    mom
#  [m]      [m]      [nm]      [nm]       [mrad]      [mrad]      GeV/c
 0.8300   0.0800     22.0000    3.3000      25           0         18  
#
# name    center_z center_x center_y rad1  rad2    length   angle      B      
gradient 
#           [m]      [m]      [m]    [m]    [m]      [m]    [mrad]     [T]    
 [T/m]  
  Q0eF    5.900  -0.1475    0.00   0.0250    0     1.200    -25.00    0.000   
 -12.705  
  Q2AeF    7.730  -0.1933    0.00   0.03   0.042   1.460    -25.00    0.000   
   0.00  
  Q2BeF    9.565  -0.2391    0.00   0.0436 0.0566  1.610    -25.00    0.000   
   1.155  
  Q2CeF   12.270  -0.3067    0.00   0.0690   0     2.000    -25.00    0.000   
   3.850  
# -------------------------------------
# -------------------------------------
# zeF3523d2  Electron forward  Low beta
#
# beta*_x  beta*_y  gm emit_x gm emit_y  crossing_x  crossing_y    mom
#  [m]      [m]      [nm]      [nm]       [mrad]      [mrad]     GeV/c
 0.8300   0.0800     22.0000    3.3000      25          0         18  
#
# name    center_z center_x center_y rad1  rad2  length   angle      B      
gradient 
#           [m]      [m]      [m]     [m]   [m]    [m]    [mrad]     [T]     
[T/m]  
  Q0eF    5.900  -0.1475    0.00   0.0250    0    1.200   -25.00    0.000    
-17.325  
  Q2AeF    7.730  -0.1933    0.00  0.03    0.042  1.460   -25.00    0.000     
 5.582  
  Q2BeF    9.565  -0.2391    0.00  0.0436  0.0566 1.610   -25.00    0.000     
 6.814  
  Q2CeF   12.270  -0.3067    0.00   0.0690   0     2.000   -25.00    0.000    
  0.000  
# -------------------------------------
# ---------------------------------------------
# zpR3513g  Hadron Rear  275 
#
# beta*_x  beta*_y  gm emit_x gm emit_y  crossing_x  crossing_y    mom
#  [m]      [m]      [nm]       [nm]      [mrad]      [mrad]      GeV/c
 0.9000   0.0430     20.0000    6.1000      25          0          275  
#
# name center_z center_x center_y rad1    rad2   length   angle      B      
gradient 
#         [m]     [m]     [m]      [m]     [m]     [m]    [mrad]     [T]     
[T/m]  
Q1ApR   -6.200   0.00    0.00   0.0201   0.0256   1.800     0.00    0.000    
-83.417  
Q1BpR   -8.300   0.00    0.00   0.0280      0     1.400     0.00    0.000    
-83.417  
Q2pR   -12.000   0.00    0.00   0.0500      0     2.000     0.00    0.000     
77.000  
# ---------------------------------------------
# -------------------------------------
# zeR3513g  Electron Rear  18 
#
# beta*_x  beta*_y  gm emit_x gm emit_y  crossing_x  crossing_y    mom
#  [m]      [m]       [nm]     [nm]       [mrad]      [mrad]      GeV/c
 0.8300   0.0800     22.0000    3.3000      25           0         18  
#
# name    center_z center_x center_y rad1  rad2   length    angle      B     
gradient 
#           [m]      [m]      [m]    [m]   [m]     [m]      [mrad]     [T]    
 [T/m]  
  Q1eR   -6.200   -0.1550    0.00  0.066  0.0795   1.800    -25.00    0.000   
 -14.460  
  Q2eR   -8.300   -0.2075    0.00  0.0832 0.0938   1.400    -25.00    0.000   
  13.740  
  B2eR  -12.250   -0.3063    0.00  0.0975 0.1388   5.500    -25.00   -0.18    
  0.000  

# -------------------------------------

Attachment: 12_14_18-ir-v3.pdf
Description: 12_14_18-ir-v3.pdf

Attachment: 6IR Layout Development Update 2019-01-02.pptx
Description: 6IR Layout Development Update 2019-01-02.pptx