Spectrap Electronics Stefan Stahl measurements by Stefan Stahl & Zoran Angelkovic Latest result of commissioning and tests

Spectrap Electronics

Stefan Stahl

measurements by

Stefan Stahl & Zoran Angelkovic

Latest result of commissioning and tests

Spectrap Collaboration Meeting, 1. March, 2010

Spectrap Evaluation of Cryogenic Components

Preface: main objectivesPreface: main objectives

challenge : low final temperature close to 4.2K

• Resistive Cooling of captured ions to T = 4.2K and ion detectionResistive Cooling of captured ions to T = 4.2K and ion detection

• Rotating Wall CompressionRotating Wall Compression

• FT-ICR Detection (optional)FT-ICR Detection (optional)

challenge : FT-ICR and rotating wall compression at the same time

m · D²

q² · R



Amplifiers and FiltersAmplifiers and Filters



Coils and Electronics Base PlateCoils and Electronics Base Plate

Teflon-isolated copper-wireon a PEEK core

Base Plate connectedto Alu-flange, holdingThe trap structure



Arrival DetectorArrival DetectorIdea: Schottky Pickup Detects Arrival of Ions => and Captures the Ions

Challenge: Height Image Pulse ~ 105e ~ 300µVCapture Pulse: 1kV / 25ns ~ 3Mio times higher signal on Detector

STRONG Protection needed !



Arrival DetectorArrival Detector

3rd Version



Arrival DetectorArrival Detector

enc = 780 erms (elementary charges)



Integration Test at 300K and 77KIntegration Test at 300K and 77K

• Cryogenic Biasing Filters

• Axial Amplifiers (GaAs FETs)

• Cyclotron Amplifiers

• All together in Conjunction with Room Temperature Box



Amplifier/Resonator Noise Tests, 77KAmplifier/Resonator Noise Tests, 77K

500kHz-coil 1.5MHz-coil

Cyclotron Detector:



Summary and OutlookSummary and Outlook• All amplifiers and filters have been successfully

tested at 300K and 77K

• Cooling Resonators work as expected

• Integration tests (300K & 77K) have been accomplished successfully

• Arrival Detector (3rd version) has been improved and tested at 4.2K, enc = 780e rms

• Tests WITH trap mounted and connected to electronics, adjust resonator frequencies @ 300K

• Test Rotating Wall coupling to electrodes

• Final integration test inside magnet and at 4.2K

• Software control of devices

To do (next weeks)



Thanks a lot foryour attention.

Email: [email protected] www.stahl-electronics.com



Spare Slides:Spare Slides:



Examples of Coil-Design



Pickup-Elektrode

Pickup-Elektrode

x

y

Detection of Image Charges, FT-ICRDetection of Image Charges, FT-ICR



Pickup-Elektrode

Pickup-Elektrode

ion currentsignal

I

t


x

y



Pickup-Elektrode

Pickup-Elektrode

ion currentsignal

I


x

y

very smallsignal ~fA

Signal strength

D ~ distance of pickup electrodes



Pickup-Elektrode

Pickup-Elektrode

ion currentsignal

z

Voltage/Current Amplifier

Pe nning Tra p(c ro ss se c tio n)

ra d ia lly sp lit e le c tro d eslit

FFTFou rie r-Transfo rm - spectra l analyser

excited ion

m agnetic fie ld

low noiseAm p.

timetime-domain frequency-domain

I

frequency

dP /d fion current signal

mass spectrum

FFT

q/mspectrum

II

t f

x

y

very smallsignal ~fA


„FT-ICR“ Fourier-Transform Ion Cyclotron Resonance




• Method is non-destructive

• Many ion species can be detected at the same time

• Small sensitivity to space charges compared to TOFSmall sensitivity to space charges compared to TOF

• Useful over a very wide range of ion numbersUseful over a very wide range of ion numbers



FT-ICR CircuitryFT-ICR Circuitry



First HFirst H22OO++ Resonance: Resonance:



Shot Noise by Ions and ElectronsShot Noise by Ions and Electrons

Creating shot noise while flying through

1010 electrons/sec. ~ 6 fA/ (Hz)1/2 1012 ions/sec. ~ 700 fA/ (Hz)1/2

Documents

Spectrap Electronics Stefan Stahl measurements by Stefan Stahl & Zoran Angelkovic Latest result of commissioning and tests