Symbiosis of DAQ, Accelerator Settings, Diagnostics, and ... · Christophor Kozhuharov, GSI...

Christophor Kozhuharov, GSI DarmstadtFirst FAIR FEE Workshop, Oct 11-13, 2005 Symbiosis of DAQ, Accelerator Settings, Diagnostics,

and Slow Controls at Experimental Storage Rings

Experiments at Storage Rings

Symbiosis of DAQ, Accelerator Settings, Diagnostics, and Slow Controls

Illustrative Examples:Particle Detection by Means of Schottky-Noise Frequency MeasurementsRevolution Frequencies at the Transition Settingof the Experimental Storage RingPhoton-free Precise Spectroscopy by Means of Dielectronic Recombination



New exprimental possibilities at Super-FRS/NESR

Super-FRS

SIS

CR

NESR

Low-Energy Cave

High-Energy Cave

cooler

e-target

Larg

e pr

oduc

tion

rate

sof

radi

oact

ive

nucl

ei

• Separate Ring, CR, with stochastic cooling• NESR with a cooler and with a separate ultracold e-target



Experimental Storage Ring, ESR

Injection fromSIS/FRS

Electron Cooler/Target RecombinationDetector

Reinjection toSIS

Schottky pick-up

Circumference 108.4 mEnergies 4 - 500 MeV/uIons (Li) C6+ - U92+



Particle Detection in Storage Rings by Means of Schottky-Noise Frequency Measurements

Basic features of the Schottky noise method.ESR-Experiments as Examples for:

Non-destructive non-instantaneous particle detection.Broad band detection of a multitude of masses (momenta).Frequency (momentum, mass) resolving power.Count rate: dynamics; number of particles.Sensitivity, single particle detection.

Schottky–noise equipment for the ESR experiments:Schottky-noise sampling.Time Capture Data Acquisition, TCAP-DAQ.

Outlook:Electron cooling force spectrometer. R&D topics, developments, and improvements



Frequency Measurements by Schottky Noise

S

D+ 45 dB

+ 45 dB

Sum/DifferenceSwitch

l/2 -Resonator

l/2 -Resonator

SchottkyPick-ups

LORF

LocalOscillator

Mixer

IF

On-line FFTAnalysis

Raw datastorage

Off-line FFTAnalysis

Stored ion beam

f ~ 2 MHz0

Low-passfilter

~60 MHz

ADC

t/T

U

Singlestored ion

f

~1f

f ~2 MHz0h f0 (h+1)f0 (h+2)f0

Storedion beam

1 2 3 4 . . .

. . .

f/f

dP/df

1 2 3 4 . . .

. . .

0

FFT

fD

f

pD

p~

P ~ N Q2

dP

/df



Cooling: narrowing velocity, size and divergence of the stored ions



Schottky Signal of the Bound-State β-Decay 187Re75+ 187Os75+

187Re75+

primary beam2⋅108 ions 187Os76+

3⋅102 ions

after 5.7 h storage

T1/2 (187Re75+) = 33(2) yIons in super nova explosions are highly ionized.



Mass Measurements at ESR



Time Capture Data Acquisition (TCAP DAQ)

HP

E14

01B

VX

I-M

XI

datum incbc350VXI

TFP16-chScalerCAENV260

96-ch I/OHP E1458AADC

triggerbox HP E1562A

Data &SCSI module

HP E1430AADC

VXI busHD

swap disk 1

HD

HD

Linux PC

RAID 1

RAID 2

swap disk 2

Schottky-noise signalfrom mixer

trigger

10 MHzsampling frequency

Analog input

Local

bus

VXI bus

Slow controls

block header information sources



Schottky Noise SamplingAnalog input

Inputamplifier

Anti-aliasfilter

SamplingADC

Clockgeneration

Zoom anddecimationfiltering

Dataformatting

FIFOmemory

Dataoutput

Triggerdetection

(ADC trigger)

Externaltrigger

Externalclock(TFP)

Send dataregister

VXI backplane

Controlregister

Clockto/from

othermodulesSync

to/fromother

modules

Thruputcontroller

Local

bus

High SpeedFIFO

4 MB/smax

40 MB/smax

SCSI-2controller

Externalwide

differentialSCSI

HP E1562A

Externalsingle-endedSCSI



Broad Band Detection of a Multitude of Nuclides



Schottky Mass Measurements

Resolving power 2x106 Accuracy 30 keVSensitivity 1 ion (Z > 40) T½ > 1s 285 new masses

150m

,g65

+

Dy

150

65+

Tb

143

62+

143m

,g62

+

Eu S

m

157

68+

Er

127

55+

Cs

157

68+

Tm

173

75+

166

72+

166

72+

180

78+

Pt

Re

Hf

Ta

152

66+

152

66+

Ho

Dy

159

69+

159

69+

136

59+

Tm

Yb

Pr

W

164

71+

171

74

Lu

164

71+

Hf

145

63+

122

53+

Gd

I

175

76+

161

70+

138

60+16

170

+

168

73+

168

73+

Os

TaW

Yb

Nd

Lu

149

65+

Tb

156

68+

156

68+

Er

Tm

154

67+

154

67+

HoEr

163

71+

147

64+

147

64+

147

64+

Dy

Tb

Gd

Lu

165

72+

165

72+

172

75+

163

71+

170

74+

Hf

TaRe

W

Hf

10000 20000 30000 40000 50000 60000 70000 80000 90000 100000

8

7

6

5

4

3

2

1

0

Frequency / Hz

Inte

nsity

/ arb

. uni

ts

mass known mass unknown

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.65

0.70

Inte

nsity

/ arb

. uni

t s

Frequency / Hz

143 62+gSm

143 62+mSm

754 keV

33800 33900 34000 34100 34200 34300 34400 34500

(1 particle)(1 particle)

m/ m 700000� ~~



Integration Time

1 block, 0.1 s

96 averaged blocks, 10s



dP

df

(a.u

.)

frequency (Hz)



Decay of a Single Stored Ion

0.95

0.87

0.77

0.44

0.67

0.80

0.62

0.57

0.52

0.48

0.40

inte

nsity

/ ar

b. u

nits

127300 127400 127500 127600 127700 127800 127900 128000 128100 128200

reco

rdin

g tim

e / s

econ

ds

0

30

60

90

120

150

180

240

192 81+Pb

192 81+Tl

frequency / Hz

e capture

Q = 3.37MeV

-

ec



The Experimental Storage Ring, ESR



First Direct Observation of Bound-State β-Decay



Time traces of bound beta decay

Left: isomeric nuclear state

Middle: bare Tl-206 g.s.

Right: β(b) daughter == H-like Pb-206



R&D Topic: Multiple Schottky Pickups and FFT

Signal/Noiseand/or time gain = √ n'Coincidence technique with replay capabilities'Multi-dimensional Fourier expansion of amplitudes and phases.Position information?

SchottkyPickups?

NESRElectronTarget

Cooler

ParticleDetectors

Electron

Gas-JetTarget



Cooling Force

Measured Longitudinal Cooling Force at ESR (Th. Winkler et al.)

as a function of the relative velocity between the ions and the electrons as a function of the ion charge



Basic Idea of the Cooling Force Spectrometer

Observable: Time dependent increase of the ion intensity in the cooled peak.

Tuning Parameters:Cooler voltageElectron current

Result:Velocity (Momentum) distribution

(AIC-proposal)



Mass Measurements at ESR



Isochronous Mass Measurements at ESR

Trigger from injection

20GS/s , 10GS/s 2 channels

Tektronix

DigitalOscilloscope

TDS 7404

Ion

B

E

Ethernet

SCSI-Bus

remote co

ntrol

ESR

H K R1 2345.452 4378.453 4578.654 1443.565 1784.546 4777.727 2789.38

PC2

Datastorage

5 GHz bandwidth, 10 GHz sampling rate2 channels with 64 MB fast memory

new: 15 GHz, 40 GHz sampling rate (2 ch.) 64 MB fast memory per channel



Data Analysis

-0.6

-0.8

-0.4

-0.2

0

0.21 turn 3 turns 2 turns

Signal [V]

13.5 14.0 14.5 15.0 15.5 16.0 16.5 17.0 17.5

Revolution tim e [µs]

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2Signal [V]

Zeit

2 ns2 ns 2 ns

140

120

100

80

60

40

20

0530 532 534 536 538

Um laufzeit [ns]

Teilchen, gewichtet

528

Se

As

Ga

Ge

Zn Cu

Ni Fe

Co

Mn

Cr

V Ti

Sc

Ca

Br

72

70

68

66

64

62 60

58

56

54

52

50

48 46

44

42

Zn

Cu

Ni

Co

Fe

Mn

Cr

VTi Sc Ca

K

Ar

Cl

S

P Si

Al

Mg

Na

61

59

57

55

53

53m

51

49

47

45 43

41

39

37

35

33

31

29

27

25

23

Cu

Kr

Br

Se

As

Rb

Ge

Ga

Zn

Ne

21

61

75

73

71

69

67 65

63

77



Dielectronic Recombination

A q++ e- → [ ]A (q-1)+ ∗∗

(time-reverse to autoionization)Dielectronic Capture (DC)

A⇒ σ ∝ DC a

→ A(q-1)+ n ⋅ hν+

Radiative Stabilization(in competition to autoionization)

⇒ σ = DR σ ⋅DC [ ]Σ Ar

Σ Σ A + Aa r

Two observables: recombined ion or photons (e.g. EBIT, RTE @ Gasjet)



Experimental Setup

Aq+

ion-

beam

Eion ≈ 90 - 100 MeV/u⇒ vion≈ 0,41 - 0,43 cIion < 1 mA (7 x 107 ions)

Merged circulatingIon beam andcooler electron beam

Ucath = 45 - 55 kVIel = 80 -100 mA

e-beam

Co-propagating beams⇒ 0 ≤ Erel ≤ 400 eV@ 0 ≤ ∆Ulab≤ 10000 V

A (q-1)+

detector

Detection of therecombined ions A (q-1)+

with single particle detector

drift tubes -5 kV … +5 kV

Variation of Erel:fast energy scan(approx. 1500 pts. à 40 mswith intermediate cooling)

⇒ Rate coeffizient α(Erel)on an absolute scale

α

Erel

α σ(E ) = v (E )

=

rel rel rel⟨ ⟩

R γ2 N n L/UIon e

-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.005

101520

~ 5eV

E cm [

eV ]

Ulab [ kV ]

Highest sensitivityat very low

collision energies

-5.0 -4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 5.00

50

100

150

200

250

300

350

400

βion = 0.413 U

Cath = 50.0 kV;

Cooling @ UDrift = 0 V UCath = 55.0 kV;

Cooling @ UDrift

= -5 kV

E cm [

eV ]

Ulab

[ kV ]



Experimental Storage Ring, ESR

Injection fromSIS/FRS

Electron Cooler/Target RecombinationDetector

Reinjection toSIS

Schottky pick-up

Circumference 108.4 mEnergies 4 - 500 MeV/uIons (Li) C6+ - U92+



Determination of the 2s1/2 - 2p1/2 Splitting

0.0

0.5

1.0

1.5

2.0

Au75+ (1s22p1/2

nl j)

E (2s1/2 - 2p

1/2 )

1000/n2

α [

arb.

uni

ts ]

60 80 100 120 140 160 180 200 220

n=35

n=24n=25

n=30

n=23

Relative energy [ eV ]

n = 20n = 21n = ∞

E ( 2s1/2 → 2p1/2 )

Main Idea: Extrapolate to the

series limit!• fine structure of peaks• distribution of individual resonance strengths• apparaus function (velocity spread of electrons)

Additionally taken into account:



Relative Contributions to the 2s1/2 -2p1/2 Energy Splitting (Li-like Ions)

Sensitivity :0,5 % of „QED“< 7 % of QED in order α2

< 3 % of nuclear sizecontributions

(on an absolute scale)

208Pb remains an idealcandidate for QED tests

QED or nuclear pyhsics ?

nuclear charge Z rela

tive

cont

ribut

ions

to th

e 2s

- 2p

spl

ittin

g1/

21/

2

(-) nuclear size

experimental uncertaintiesC. Brandau et al., PRL (2003) 07320291

QED: Yerokhin et al. (2001,2002)

Experimental uncertaintiesfrom:Bosselmann et al. (1999)Feili et al. (2000)



Isotopic Shift of Li-like 142Nd57+ vs. 150Nd57+

by Means of Dielectronic Recombination at ESR

0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0

100

200

300

400

500

Rat

e C

oeffi

cien

t [A

rb. U

nits

]

Electron-Ion Collision Energy (c.m.) [eV]

A=142 A=150

Nd56+ (1s2 2p1/2 18lj )

n = ∞n = 18

2p1/2

2s1/2

...

preliminary

C. Brandau, C. Kozhuharov, A. Müller et al.

First preliminary results of a pilot experiment performed at ESR in August 2005



Ultracold Electron Beam

10-4 10-3 10-2 10-1 100 101 102 10310-4

10-3

10-2

10-1

100

kT⊥ = 120 meV

∆E|| = 4(

ln2 E

rel kT

|| )1/2

current ESR∆E = ( ∆E

⊥

2 + ∆E||2 )1/2

∆E⊥ = kT

⊥ ln2

Ener

gy s

prea

d [ e

V ]

Relative energy (eV)

kT|| = 0.1 meV

10-4 10-3 10-2 10-1 100 101 102 10310-4

10-3

10-2

10-1

100

lower transversaltemperature(current TSR, CRYRING)kT

⊥ = 1 meV

kT⊥ = 120 meV

∆E|| = 4(

ln2 E

rel kT

|| )1/2


⊥

2 + ∆E||2 )1/2

∆E⊥ = kT

⊥ ln2

Ener

gy s

prea

d [ e

V ]


kT|| = 0.1 meV

10-4 10-3 10-2 10-1 100 101 102 10310-4

10-3

10-2

10-1

100

lower longitudinaltemperature

lower transversaltemperature(current TSR, CRYRING)kT

⊥ = 1 meV

kT⊥ = 120 meV

∆E|| = 4(

ln2 E

rel kT

|| )1/2


⊥

2 + ∆E||2 )1/2

∆E⊥ = kT

⊥ ln2

Ener

gy s

prea

d [ e

V ]


( theoretical limit 50 kV), kT

|| = 0.2 µeV

kT|| = 0.1 meV

Present ESR:kT given by cathodeheating and fast accelaeration

Adiabatic expansionof the electron beam

lower transversal kT:

Adiabatic accelerationof electron beam

lower longitudinal kT:

Further reduction of kT with cold (80 K) photo cathodeHas been demonstrated at MPI-K in Heidelberg.



KLL-DR-Experiments at ESR

Basic Idea: The ion beam is cooled stochastically. The electron cooler serves solely as an electron target.

mittlere Position imPhasenraum

x

x

x’

x’

Kicker

Pick-up

Stochastic Cooling : The average position of a sample in the phase space is detected. This defines thecorrection of the kicker.

Combiner-Station

long. Pick-up

transv. Pick-up

long. Kicker

transv. Kicker



First Measurement of KLL-DR-Resonances in U91+



Conclusions

The symbiosis of experimental FEE with special accelerator settings, with the slow controls, and with the diagnostics has been the base of several successful experiments.Opportunity knocks but once—the present planning of the future accelerators, of their diagnostics and slow controls ought to ensure a large bandwidth of networking and interfacing between the experiments and storage rings.



Conclusions

Particle detection in storage rings by means of Schottky-noise fast Fourier transform frequency measurements is a versatile tool for non-destructive non-instantaneous measurements.A broad band of masses or of momenta can be detected.The mass and/or momentum resolving power is excellent.Intensities and lifetimes can be measured as well.The count rate dynamics is up to eight orders of magnitude.One single highly-charged heavy-ion can be detected.The data—taken continuously—can be handled and stored.There is room for improvement, research and development:

multiple Schottky pickups and correlated FFT.electron cooling force spectrometer

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Symbiosis of DAQ, Accelerator Settings, Diagnostics, and ... · Christophor Kozhuharov, GSI...

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