Why is this important?

Janurary 12, 2005 Dave Johnson RR Dept Meeting 1

• Why is this important?– We want average corrector current to be zero (not contribute to central

trajectory)– Reduce feed down from quad and sextupole in gradient magnet

• Determine true tune/chromaticity/coupling from Recycler permanent magnets

– Match complex to true Recycler energy (w/o corrector contribution to average dipole field)

– Reduce/eliminate dependency on DC magnetic elements, use magnet moves to reduce corrector strength (0.2A max) and install PM quad trims in phase trombone

• Some statements– The Recycler central trajectory should be “as defined by the design lattice”.

– The BPM’s were specified to lay on the central trajectory with dp/p as zero

– The BPM’s/beam pipe were installed to centered on this central trajectory

– The gradient magnets were installed with a specific sagatti (and longitudinal offset) correction to minimize feeddown and maximize aperture.

Defining a “Golden” Closed Orbit (smoothed ‘n centered) beams doc 1540


• Factors in absolute BPM readings– Data for individual channels

• Survey offset • Electrical center of plates• Electronic offset (cables+electronics)

– Data for BPM type• Gain (mm/volt)

• In process of verifying gains/offsets installed in front end

• Rechecked lattice specification and survey technique

– Magnets survey w/ Laser tracker (not shown)

• Radial = 0.001mm , = 0.041 mm• V = 0.002 mm, = 0.022 mm• Roll = -0.024mr , = 0.201 mr

– BPM/beam pipe optical survey • PLOTS to the right ->• Parallel offset to mini straight as

defined by up/down stream gradient magnets/quads (using sagatti corrected offsets)

Horizontal BPM Set- Ideal

0

5

10

15

20

25

30

35

B P M Off s et [mm]

Recycler BPM’s (do we trust them?)

Vertical BPM Set- Ideal

0

5

10

15

20

25

30

35

40

45

B P M Off s et [mm]

+/- 1.6 mm

+/- 1 mm

Horizontal

Vertical

OBPM Survey Offsets installed in front end

Results of global BPM survey 2001


rms 7.3 mmdp/p 0.0013Xmax ~16 mm

rms 1.38 mmaveg -.174mmXmax ~16 mm

Our Current Operational Orbit

After Stan’s vertical aperture scan

Centering in physical aperture


Corrector Settings for Current Operational Orbit

.157*117 ur/A = <18.4 ur> inside

corr / dipole ~ 0.001

-.305*73 ur/A = <22.3 ur> down


Closed injection to same effrms 3.7 mmdp/p 0.0002Xmax ~ 2 mm*

Smoothed* and Centered* Orbit

S•Centered Orbit by Rfreq•Smoothed using R50 to select dipole/region for smooth•Not smoothed MI30 or MI60•Avoided LEP corr (for now)•Fixed positions thru known apertures

First pass at adj tunes

Admittance > 90

* First pass

Coupling/chromaticity NOT adjusted

KnownOffsets


• RF freq: 52809500 -> 52809000 (only approximate now) • Revolution freq: reduced by ~0.85 Hz (89812.0748 Hz -> 89811.2244 Hz) • Revolution period: reduced by ~ 105 ps• dp/p (RR) = -0.0011 (

• Impact on MI and complex– MI/complex energy reduced by ~ 8 Mev

• Impact on RR BPM– only 89 kHz and narrow band – Minor impact

• Schottkies– Mixdown frequencies

• Stochastic Cooling – delay times between pickup and kicker change by ~20 ps

• Electron Cooling• RF (low level wave forms)

Recycler frequency change


Corrector Currents for Smoothed Orbit

.027*117 ur/A = <3.1 ur> inside


TM-2134 Meiqin, et.al.

Dynamic Aperture

25.5 mm

38.25 mm

Dp/p = +0.003

Current central orbit p/p +.0014Typical p/p(90%) +/-.0015

Working point (.425, .415)for this calculation

Chromaticity = -2 units


x

Working point

Current Operating PointQh ~ .414-.415Qv ~.412

For = -10,And p/p ~.0015v = +/-0.015 each plane(into 5th and 7th)

For = -2,And p/p ~.0015v = +/-0.003 each plane(into 12th)

Approx. tune spread for = -10shown on plot

For p/p of .0015 maximum to avoid 5th and 7th order resonances


5280

9500

5281

0250

5280

8750

1250 Hz

Data taken by Stan… Extinguish points are 52805750 and 52813300 for momentumaperture of +/- about 3800 Hz. MI is not ramping for this data, H and V chromaticityis about -2.5 unit.

p/p>0 < 0

p/p>0 > 0

2500 hz 3000hz

Current Momentum Aperture12/3/04


Tunes

Current Orbit Smoothed OrbitCurrents: 0.427, 0.040, 0.489, -0.679, 0.172

Currents: 0.808, -0.239, 0.919, 0.016, 0.395

*No attempt to adjust coupling or chromaticity

Trims: 2/half-cell @ 0.027 T/A PM quad: 4/half-cell @ .85 T trims contribute 1.6% of focusing at 1 amp

Qh ~ .414Qv ~ .415


“Bare Machine” Tunes

Qh .4099Qv .4310

Qh .4131Qv .4393

Qh .4216Qv .4349

Schottky

VSA (uncorrected)

Nov 30, 2004

January 11, 2005

Design.425/.415

Measured Harm.4269 / .4022


Horizontal Admittance

22.3 mm

21.7 mm

Operational orbit

Smoothed orbit

A = 0.02232*9.52/52A > 90 -mm-mr


Our Current Operational Orbit

•Smoothed orbit with freq at 52809000 Hz •Increased freq back to 52809500 Hz•Orbit difference shows dp/p +0.0014•Contribution +0.0011 from freq change

Dp

p/p = -(1/)f/f

=(1/tr2 – 1/2)

= -0.00851

tr = 19.968


• Include all offsets in BPM front end (in progress) • Smooth orbit (reduce average corrector strength)• Determine quad moves to reduce largest correctors (MI30 and MI60)• Adjust freq to get a zero dp/p with average corr current zero.• Investigate apertures in MI60 and MI30 Center beam in phase trombone quads (H & V rms < .1mm / 5A) - Jan 11• Adjust coupling (what’s the source)• Adjust chromaticity • Determine momentum aperture • Determine source of “bare machine” tune shift (X =-.0034 , y =+.02)• Measure sensitivity of lifetime due to tunes• Re-tune injection/extraction (may require adjustments to closed orbit/counter-

wave in MI)• Re-adjust cooling/instrumentation to centered Recycler frequency• Match MI (and eventually the complex) to this new frequency/energy• Revisit MI ramp compensation

What Needs to be Done

Documents

Why is this important?