Dave Johnson
July 12, 2010
NOvA/ANU Recycler Upgrades Review
Optics, Apertures, and Operations
Nova-doc 4930
Opening Statements
7/12/2010
2
d
Optics
Injection & Extraction transport lines can be described as FODOlattices with beta functions very similar to the Recycler and MI (i.e.maximum betas ~60 m or less) and vertical achromats.
Apertures
d
Operation
d
Recycler Injection
7/12/2010
3
Continuation of 8 GeV line FODO lattice using permanent magnet dipoles andquads with the addition of a vertical achromatic dogleg
847
101
103
Recycler
8 Gev line
100
850
102
104
V1 (switch)
V2 (PDD)
HBEND (35 mr)
VLAM (MLA)
K
HKICK
848
MI8
849
852
851
103
102
MI
QR853
QR852
PDDM
H
102
Inj kicker
lamb
Vup
Vdn
•Usual complement of BPM’s, Lossmonitors, multiwires, and correctionelements
Only two power supplies required:
Vertical switch magnet (ADCW)
Injection Lambertson (MLAW)
•Powered trim quads (MQT) are
included for matching.
Recycler Extraction
7/12/2010
4
Vertical achromat between RR and MI (FODO lattice similar to MI)
Design similar to existing R22 and R32 transport lines
Permanent magnet quads (with electromagnet trims, MQT)
•Usual complement of BPM’s, Lossmonitors, multiwires, and correctionelements
Only 3 power supplies required:
•Extraction Lambertson (MLAW)
•Vertical Dipoles (ADCW)
•Injection Lambertson(ILA)
•Powered trim quads (MQT) are
included for matching.
Recycler Abort Line (existing)
7/12/2010
5
Recycler abort line shares the beam absorber with the MI.
Contains vacuum break downstream of the Lambertson (do we keep ?)
Abort kicker double duty as pbar extraction kicker (pbar function will go away with Nova)
NEW > Install gap clearing kickers so the beam in the injection gap is cleanly sent to the absorber
400
LAM402
KICKER
LAM402
MI EnclosureWall
Dump
402
5
Assume ~5E13/1.33 sec
Assume 2% in gap
1E12/1.3sec
1 kW
Oct 2000
Recycler e-log
RR
MI
Apertures
7/12/2010
6
Expect NOvA Booster batch intensity at approximately the same as today~4E12/batch
Current measured transverse emittance of beam from Booster (during slip stackingoperation) is roughly 12-14 -mm-mr.
6 values of 21.6mm to 23mm and 10 values of 36mm to 38.4mm (for beta=60m)
Minimum injection line physical apertures based upon a 10 beam envelope for a25 -mm-mr emittance (=5.14mm @=60m)
Minimum extraction line physical apertures based upon a 10 beam envelope for a20 -mm-mr emittance (=4.6mm@=60m)
Utilize same style of beam pipe that exists in the MI, RR, and 8 GeV.
The ADC dipoles and the MLA Lambertsons are having new versions built withwider apertures.
The main aperture constraints are at the injection extraction points (partiallymitigated by creating a larger aperture Lambertson)
Beam pipe choice considered installed magnet pole tip dimensions and designlattice functions (expected beam size). Details in following talks!
Apertures (2)
7/12/2010
7
A partial list of magnet and beam pipe apertures
Magnet type
Shape
Hor
Ver
Hor
Ver
[in]
[in]
[mm]
[mm]
ADCW (could be 2x4” MR rect pipe)
Special
1.88
5.0
51
124
PDD (& PDS)
Elliptical
3.8
1.75
96.5
44.5
PDD_rolled
Elliptical
1.75
3.8
44.5
96.5
PM Quad Pole tip
3.28
83.3
MI beam pipe
Elliptical
4.6
2.0
117
51
Recycelr beam pipe
Elliptical
3.8
1.8
95
44
ILA (field region) existing
rectangular
2.0
12.0
44
305
MLA (field region) modified
rectangular
2.0
4.7
51
120
between dipoles (4”OD)
Round
3.88
3.88
97
97
3” round beam pipe (through PMQ)
Round
2.88
2.88
73.2
73.2
8Gev bpm (4”OD)
Round
3.88
3.88
97
97
Recycler bpm
elliptical
3.8
1.75
96.5
44.5
Use at horizontal
quad locations
Use at vertical
quad locations
Apertures Recycler Injection
7/12/2010
8
Provide for loss free transmission
Expect emittance of 12-14 (history shows withlarge tails)-> clean up with MI8 collimation
Would like to provide at least 1 for loss freesteering
Assume 99% in 6 -> use 10 with 25 beam
Vertical aperture
Min horizontal aperture
Apertures Recycler Extraction
7/12/2010
9
Maximum beta ~60m atquad locations (10 of 25= 51.4mm)
Vertical locations utilize 3”beam pipe (73mm) whilehorizontal locations use RRbeam pipe (95mm)
Recycler Extraction Lambertson
Main Injector Injection Lambertson
Apertures Recycler Abort
7/12/2010
10
Abort line apertures OK for 10 of 14
H ellipse
4” round
24” round
H
V
V
V
L
V ellipse
H ellipse
V ellipse
4” round
24” round
Horizontal aperture (red),
vertical aperture (blue)
10 of 14
10 of 25
6 of 25
Need to perform aperture scan
of abort line… schedule during start up
Operation
7/12/2010
11
Booster is assumed to be operational at 15 Hz
Expected operational scenario
Injection takes place during MI ramping (implications due to stray field on injection line)
We expect all injections into Recycler will occur without interruption, but we will have the capabilityof interleaving injections at a 15 Hz level
Gap clearing kicker at RR40 to clear any beam in injection gap before each injection
Beam extracted without capture in 53Mhz (MI is at 8 GeV)
Tuning
Instrumentation
4 MW in beam lines
4 MW in Recycler
BPM’s
Loss monitors (extra loss monitors around Lambertsons and switch magent
Steering
Define position and angle mults at Lambertson (approximately 2mm/amp on corrector for injection line)
Define Recycler closed orbit bumps (both injection and extraction Lambertsons)
Define MI closed orbit bumps around Lambertson
Modify closure program to Recycler and MI injection
Matching
The permanent magnet gradients for both transport lines set to match into Recycler/MI with the trim quads set to zero
Permanent magnet strength ~25 kG/m (2 or 3 at each location) 50 to 75 kG/m
Trim quads (MQT) 0.9 kG/m/Amp with 2 at each location 1.8 kG/m which gives a 24 to 36% quad strength tuning range for10 Amps
Recycler lattice functions ( may be adjusted +/-25% with less than 6 amps on any trim quad
Use profile matching for Recycler injection (MW) and TBT sigma matching for MI injection (IPM) with profile matching in bothtransport lines.
Summary
7/12/2010
12
The transfer line optics design were based upon existing transfer lines such as the 8GeV line and RR22/32 (i.e we have experience designing and building permanentmagnet lines and rings)
The transfer line optics have been firm for well over two years.
Beam line designers have worked closely with the Mechanical Support Department(Linda and Bill) to optimize locations of elements and specify appropriate beam pipeapertures.
Plan to document existing Recycler abort aperture
Power supply regulation requirements and tuning scenarios have been addressed