Improvements to PEP Diagnostics

Improvements to PEP Diagnostics

Alan Fisher

PEP-II Performance Workshop 30 January to 1 February 2002

716

Measuring Beam Size with a Two-Slit Interferometer A measurement borrowed from Toshiyuki Mitsuhashi at KEK. The classic Young’s two-slit experiment: Pass light from a monochromatic point source through two slits, then recombine on a screen.

l

Each slit separately produces a broad interference pattern, depending on the slit width.

l

Because a point source is coherent, the two single-slit patterns interfere to produce fine modulation of the single-slit fringes..

l

Partial coherence of quasi-monochromatic light at 4 and P2, from a small but nonzero source S: l If IS4 - SP2I

Py 0

New Tune Pickups px w

@Ycm>

LER

3.1

25.4

23.1

25.4

HER

24.5

9.9

37.3

36.9

Status l l

Most parts have arrived. Assembly underway. Heliax cables for the additional buttons were sent flattened in places and are being replaced. 735

Original PEP-II The Monitor

OChl

Ax = (6 + Y) - (R + G)

C=B+R+G+Y

0-70dB

Gate

Band Pass

2-ns rise 476 MHz

3dB

3dB 1’

qqrt/

Ch2 0

Low Pass

LO 6dB 3dB

Ch 1 HP8941 OA Spectrum Analyzer Ethernet

-+lb!d

GPIB ~DEC

952 MHz

X

il

0

1-

Excitation

--J=+ 0

Zh2

-x2

-----‘II

To H ToV To L

DEsCRlPTlON

REV

PREF 1

ITEM NO LUY-~~-61 -m -nIY-I+3..

SCALE: NT.%

wa.rsI oc+m.3c 5Ec5w mw6mtsm*

-

NEXT ASSEMBLIES:

4

W ”rr

llFuram 26s 0‘5 W I-CcelLR LO1I WI mAxme + n+ m+ -+

3

-

N-

+

YlYRFJ

EASE

1 SUFF

STOCK OR PART NO W NOT SCALE DRAWING

STANFORDLlNEARACCELERATOR CENTER uILLslRRwI(TL!EW

SwmRO. wORNK STrnD MYEWM m o p m CA,* m m ST-0 m l -ml wwm “. I. DLpulm a -.R~NIIWI*DT-w~mmum~~ aUYTmSRCFZPFRYSYONCSSUNZW-. -xEam : -

4

‘@ ,A=* 2

,,y,~ CHKR ~p,y,

TITLE OR DESCRlPllON

OATI

OM

CAD F’LE NAME:sd12592707.igs

PEPII CONTROLS TUNE MONITOR BPM SIGNAL, PROCESSOR

SD-125-927-07-CO - - --Et?

E-z2FFLe%E~~s’Rc_

C ____

Signal to Noise Comparisons

New Tune Monitor

c Component

Old System, 30dB on step attenuator, used for large peak currents (typically 2 mA/bunch) NOiSe Cascaded Power Gain Figure Gain Gain in Peak Make & Model forward (dBm) NW WV

Noise Factor

-_ _.

Cascaded Cascaded Noise Level N. Factor N. Figure forward forward (dBm/Hz)

-1t-1IJ.7n

-75.w

Attenuator 180” hybrid 180” hybrid Stepattenuator

Narda 766.3 dB, 20 W LDF4-50A, 0.5” Heliax, 0.0751 dB/m Narda 4780.6 dB, O-6 GHz, 2 W Anzac H-183-4 Anzac H-183-5 HP8495G O-70 dB

Amplifier Gate

Mini-Circuits ZHL-1072l Mini-Circuits YSWA-2-SODR, 2 in series

Band-pass filter Attenuator Amplifier Attenuator Mixer Attenuator Low-pass filter

RLC Electronics BPF-750-952-194R Narda 4780,3 dB, O-6 GHz, 2 W Mini-Circuits ZFL.-lOOOH Narda 4780,3 dB, O-6 GHz, 2 W Amac MDC-149 Narda 4780,6 dB, O-6 GHz, 2 W Mini-Circuits SLP-10.7

Attenuator Long-haul cable

ISystemGain G and NoiseFigure F Signal Power = D Component

-3.0

3.0

-4.1

4.7

-6.0 -3.7 -3.1 -30.0

6.0 3.1 3.7 30.0

0.50 0.34 0.25 0.43 0.43 0.00

25.0 -2.8

4.5 2.8

316.23 0.52

-2.5 -3.0 28.0 -3.0 -6.3 -6.0 -1.0 -22.8 -98.32

2.5 3.0 5.0 3.0 7.3 6.0 1.0 55.74 dBm

0.56 0.50 630.96 0.50 0.23 0.25 0.79

L

KOIE-01

-78.54 -83.28 -89.28

2.00 2.98 3.98

2.OOE+OO 5.94E+OO 2.37EtOl

-101.68 -104.48 -107.02 -110.02 -82.02 -85.02 -91.32 -97.32 -98.32

2.82 1.91 1.79 2.00 3.16 2.00 5.37 3.98 1.26

3.66E+O5 3.67E+O5 3.67E+05 3.69E+O5 i 3.1 3.7 3.7 3.75EtO53.7

1.68E-01 4.23E-02 1.80E-02 7.69E-03 7.69E-06 2.43E-03 1.28E-03 7.1 lE-04 3.57E-04 2.258-01 1.13E-01 2&E-02 6&E-03 5.2s03

1

55.6 55.6

-144.4 1

0.01 P.T =

-126.18

New System, 35dB on step attenuator, to get same gain as case C with old system, Noise Cascaded GailI Figure Gain Make & Model Gain (dB) forward W

dBm

Power ia Peak @Em)

Noise Factor

Cascaded Cascaded Noise N. Figure Level forward forward (dBm/Hz)

N. Factor

-1719

_.

rls.01 .81.01 86.5 1 .92.51 .93.51 ISystem Gain G and Noise Figure F Signal Power = E

Component

-18.0 -93.51

58.62 1 dBm

0.02 P.T =

-119.89

1.41 2.00 5.62 3.98 1.26

1.28&05 7.28E+O5 7.28EiQ5 7.283+05

SNR=

dBm

New System, 10dB on step attenuator, first amplifier bypassed, for same gain as cases C and iJ Noise Cascaded Power G&l Gain Figure Make 81Model Gain in Peak forward (W (dB) (dBm)

7.28E+O5 7.28E+O5

Noise Factor

-10.0 58.6 58.6 58.6 58.6 58.62 26.37 dB

Cascaded &WA&; Level N. Factor N. Figure forward forward (dBm/Hz)

-75.54

Attenuator Long-haul cable Attenuator 180” hybrid 180” hybrid

Narda 766,3 dB, 20 W LDF4-5OA. 0.5” Heliax. 0.0751 dB/m Weimchel4W-O6,6db, 0-4GHz, 2W M/A Corn H-1834,3OMHz-3GHz M/A Corn H-183-4,30MHz-3GHz

Step attenuator Low-pass filter RF bypass switch

Weinschel 151-75 R.LC Electronics F-lo-3COO-R Narda 150-A2-AlD-2AO

Amplifier Gate

Miteq AFS3-00100300-25-23P-6 Mini-Circuits YSWA-2-SODR, 2 io series

Band-pass ftiter Attenuator Amplifier Attenuator Mixer Attenuator Low-pass filter

RLC Electronics BPF-750-952- 19-4-R Weioschel4W-03,3db, O-4GHz,2W Miteq AFS3-00100200-15-ULN Weimchel4W-O3.3db, 0-4GHz. 2W Miteq DMOO52HA2 Weimchel4W-06.6db. O-4GHz, 2W Mini-Circuits SLP-10.7

SystemGain G and NoiseFigure F Sienal Power =

-3.0 -4.1 -6.0 -3.7 -3.7

3.0 4.1 6.0 3.7 3.7

-10.0 -0.4 -0.2

10.0 0.4 0.2

0.0 -2.8

0.0 2.8

-1.6 1.6 -3.0 3.0 36.0 1.5 -3.0 3.0 -5.5 7.5 -6.0 6.0 -1.0 1.0 -18.0 40.00 -93.51 dBm

0.50 0.39 0.25 0.43 0.43 0.10 0.92 0.95 1.00 0.52 0.69 0.50 3,981.l 0.50 0.28 0.25 0.79 0.02

P-, E

5.01E-01 1.94E-01 4.87E-02 2.08E-02 8.87B-03 8.87E-04 8.188-04 7.82E-04 7.82B04 4.1OE-04 2.84E-04 1.42%04 5.66E-01 2.84E-01 8.CQE-02 2.01E-02 1.60E-02 .1-u-l-41

-78.54 -82.66 -88.66 -92.36 -96.06 -106.06 -106.41 -106.61 -106.61 -109.41 -111.01 -114.01 -78.01 -81.01 -86.5 1 -92.5 1 -93.51 ARm

-1~1.1 -120.7 -126.2 -132.2 -133.2 -133.2

-I

2.00 2.58 3.98 2.34 2.34 10.00 1.08 1.05 1.00 1.91 1.45 2.00 1.41 2.00 5.62 3.98 1.26

2.OOEtOO 5.15E+OO 2.05E+Ol 4.81E+Ol l.l3E+O2 l.l3E+O3 1.22E+O3 1.28EtO3 1.28E+O3 2.44E+O3 3.52E+O3 7.03E+O3 9.93E+O3 9.93E+O3 9.95E+O3 9.99E+O3 l.OOE+O4 LOOE+04 CNRS

3.0 7.1 13.1 ILO 10.0 20.5 30.5 30.9 31.1 31.1 33.9 35.5 38.5 40.0 40.0 40.0 40.0 40.0 40.00 36.82 dB

117” I>.,

-173.9 -173.9 -173.9 ,-l,n -~,J.Y -173.9 -173.9 -173.9 -173.9 -173.9 -173.9 -173.9 -173.9 -136.4 -139.4 -144.9 -150.9 -151.9

-151.9

Tune Tracker Purpose: To track the location of the tune peak. One digital lock-in amplifier for each plane. Method: l

Shake beam at a single frequency: o Sine wave source built into lock-in. o Combine with excitation from spectrum analyzer. o Drive the beam through transverse feedback amplifier and kicker.

l

Signal that goes to spectrum analyzer also goes to lock-in.

l

Lock-in finds amplitude and phase of beam’s response.

l

Phase changes by 180” as shake frequency is swept across resonance.

l

Keep frequency at middle of phase change to track tune.

l

Monotonic: Direction of tune change known without dither.

l

Use amplitude of response to determine how hard to shake.

Could be used to monitor the tune, or in a loop to control the tune by adjusting multiknob for the tune quadrupoles. Similar in concept and sensitivity to frequency-response mode of our FFT vector spectrum analyzer, but at one frequency. l

Operators can still monitor spectrum with analyzer.

Status: l

We have one lock-in (Stanford Research Systems SR830).

l

Stephanie Allison will write EPICS software.

l

W ill observe how well this follows one tune for a while before extending the system.

739

740

0 m

9

Beam-Position Monitors Conversion of BPMs at all sextupoles from single plane to xy: Drift at sextupoles causes coupling and tune changes. Involves 135 BPMs, 93 in HER and 42 in LER. Ron Johnson estimates 850 k$ for cables, filter-isolator boxes (FIBS), and processors (RInQs), including contingency and overhead. Processors must be re-engineered to replace obsolete chips (Xilinx, frequency synthesizer). Completion goal: November 2002 (but may need more time). No decision yet to proceed. Ron Johnson’s observations of orbit drift: Several IR-2 BPMs on both rings, on both sides of the IP, followed for 70 minutes (two top-offs). Highly correlated motion in x, about 200 pm. Weaker correlation in y, with 10 to 50 pm drift. Processor errors can’t cause these correlations. Correlations give processor resolution of 1.8 pm, comparable to bench tests. Possible sources: o Feedbacks; 0 Power supplies; o Vacuum chamber motion; o Synchrotron radiation or scattered beam on the buttons.

741

__-_--_.-_

a

’