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 Contact:
   Project Coordinator
   Prof. Theo Zouros
   Atomic & Molecular Physics
   Dept. of Physics
   Univ. of Crete, PO Box 2208,
  . GR-71003 Heraklion
   Tel:+30-2810394117
   Fax:+30-2810394301
   e-mail: tzouros@physics.uoc.gr

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Home > Description of Work Packages

Description of Work Packages

The detailed time chart of all activities is given in summary in the Gantt chart Timetable. This is seen to be separated into three distinct but overlapping phases:
  1. Construction phase (WP1-7, months 1-24),
  2. Measurements phase (WP8, months 19-48),
  3. Data analysis and Dissemination of results phase (WP9-10, months 19-48).
The work packages are explained next in more detail. Additionally, in Table I (at the very end of this proposal), the names of the researchers, their expertise, their assigned tasks and their estimated effort are listed for convenience

A. Construction phase (WP1-WP7, 24 months)

Work packages 1-7 relate to the construction phase in which the entire experiment composed of beam line, ion strippers, vacuum chamber, gas cell, spectrometer, position sensitive detectors and data acquisition system will need to be designed, constructed, tested and/or put into operation.

 

Work Package

1

Start:

Month 1

 

Finish:

Month 15

Cost:

Title:

WP1: Beam line design and construction

Description:

Research Teams:

RT1, RT2, RT3

1.1 Optics design of complete beam line The optics of the entire accelerator will be checked with the CPO code TRANSPORT and compared to real beam conditions.  Then the optics of the new beam line will be designed starting from the switching magnet port L45. This will determine exactly what and where to place steerers, quadrupoles, beam monitors, slits and the optimal length to the target for highest transmission.

1.2 Beamline construction Using the optics design the new beam line will then be constructed. This includes the beam tubing, support stands, placing the focusing elements at the right place, adding gate valves, pumping ports, vacuum gauges, etc.  The machine shop will be used for many of the required constructions. Materials needed for beam line and optical elements already exist, but might need repairs.

1.3 Optical alignment of new beam line Will be performed with a telescope whose stand has to be built and aligned with alignment mark at accelerator switching magnet

1.4 Vacuum test of new beam line A turbo pump with fore line pump will be needed to bring the beam line to a vacuum of 5Χ10-7 Torr or better. If pumps not available they will have to be ordered and bought.

1.5 Test new beam line transmission with ions from TANDEM Once under vacuum fluorine or oxygen beams will be used to test beam line transmission through slits by recording ion current at the end of the beam line and comparing to current at switching magnet and expectations of CPO TRANSPORT code.

Deliverables:

1 Report and possibly part of BS, MS or PhD thesis

 

Work Package

2

Start:

Month 1

Finish:

Month 15

Cost:

Title:

WP2: Design and Construction of Ion beam strippers

Description:

Research Teams:

RT1, RT2, RT3

2.1 Foil post stripper design and construction: A self-supporting multiple foil stripper will be designed, build in the shop and placed between analyzing and switching magnet for post-stripping of the beam.

2.2 Tandem terminal gas stripper design and construction: The TANDEM tank will be opened and a differentially pumped gas canal will be positioned with turbo pump, pressure monitor and leak valve.

2.3 TRANSPORT study of beam transmission through strippers: Code TRANSPORT will be used for the optimization of the low energy TANDEM beam for optimal transmission through the terminal stripper

2.4 Implementation of charge state analysis code for optimal charge selection:. Charge state analysis code CHARGE implemented for the TANDEM parameters to predict charge distributions after stripping. 

2.5 Test of strippers and ion transmission to new beam line: Test beams run to measure the efficiency of gas and post stripping and get a better idea of the actual beam currents of highly charged ion beams

Deliverables:

1 Report and possibly part of BS, MS or PhD thesis

 

Work Package

3

Start:

Month 1

Finish:

Month 9

Cost:

Title:

WP3: 00 Auger projectile spectroscopy - Design of experimental apparatus

Description:

Research Teams:

RT1, RT2, RT3

3.1 Design of full experimental setup inside collision chamber:  Details of electron optics, gas cell and spectrometer input lens geometries will be reconsidered and partially redesigned to further improve Kansas apparatus. TRANSPORT code used to optimize ion beam transmission through the target gas cell.

3.2 Market research, ordering and receiving all required components: The apparatus from Kansas came without electronics such as signal processing amps, HV power supplies and data acquisition which have to be bought. New spectrometer support will be designed and constructed in the machine shop.  

Deliverables:

2 Reports and part of BS, MS or PhD thesis

 

Work Package

4

Start:

Month 4

Finish:

Month 15

Cost:

Title:

WP4: Collision chamber preparation

Description:

Research Teams:

RT1, RT2, RT3

4.1 Preparation of high vacuum collision chamber:  Careful study of best usage of two collision chambers brought from Kansas. The 2nd chamber is bigger than the original with more space for gas cell and spectrometer and has better mu-metal shielding advantages that need to be considered. High voltage cabling considerations. Electrical signal and noise pick-up considerations. Pumping speed analysis, selection of turbo pumps and ultimate vacuum considerations. Typically, a central turbo pump (350-500 lt/s) is needed for the chamber with a second smaller one (100 lt/s) for the target gas cell. All pumps will have to be bought.

4.2 Faraday cup construction: The Faraday cup has to be designed, built and carefully installed on the chamber. It is used to stop the beam and measure its current for monitoring and spectrum normalization.

4.3 Connection of chamber to beam line and final tests with ion beam from TANDEM: The whole chamber and Faraday cup will be tested for vacuum to about 1 x 10-7 Torr. Then it will be connected to the beam line and aligned to the beam axis on a special support stand that will be built in the machine shop. Check of transmission and current integration with ion beam from the accelerator.

Deliverables:

1 Report and possibly part of BS, MS or PhD thesis

 

 

Work Package

5

Start:

Month 7

Finish:

Month 15

Cost:

Title:

WP5: Differentially pumped gas cell - design and construction

Description:

Research Teams:

RT1, RT2, RT3

A low chamber (2-4Χ10-7 Torr) pressure with fully loaded (10-20 mTorr) target gas cell is crucial for obtaining high quality, low background electron spectra, particularly with position sensitive detection since it also reduces the dead time of the entire data acquisition This necessitates the use of a doubly differentially pumped gas cell with its own independent pumping system a concept first used with great success in Kansas.

5.1 Design of doubly differentially pumped gas cell:  calls for a voltage floatable target gas cell enclosed in an outer cell and directly pumped by an independent turbo pump with μm XYZ alignment capabilities. Supporting the gas cell at the correct focusing distance is very important and will be studied in simulation using SIMION CPO software in conjunction with the input lens settings of the hemispherical analyzer. A 50-100 lt/s turbo pump with back up pump will have to be ordered and installed.

5.2 Gas cell construction and placement in collision chamber: Gas cell manifold, aperture assembly, pumping system and support will be built according to the design in the shop and positioned.

5.3 Connection to gas feed through and pressure stabilization unit: The gas pressure will be stabilized and monitored by a feedback system, typically a capacitive manometer, which will also have to be bought.

5.4 Gas cell alignment and support: involves the crucial optical alignment of the gas cell with the optical axis and is first performed in air with a telescope. Final micro adjustment to minimize electron background from slit edge scattering is performed by taking electron spectra with ion beam on target (WP8.1).

Deliverables:

1 Report and part of BS, MS or PhD thesis

 

Work Package

6

Start:

Month 1

Finish:

Month 18

Cost:

Title:

WP6: Electronics and Data Acquisition system -design and implementation

Description:

Research Teams:

RT1, RT2, RT3

6.1 Detectors electronics: Design, purchase, and assembly: The pulses from the electron detectors of the spectrometers are processed through a system of preamps, shaping amps, logical gates and ADCs which will have to be redesigned and whose components must be bought. Spectrometer electrode voltages are delivered by programmable precision high voltage power supplies and coordinated with the detector signals through the data acquisition system (DAQ) centrally controlled by a PC. Both DAQ and power supplies must also be bought as well as related high voltage vacuum feedthroughs, SHV and MHV connectors, HV cabling etc.

6.2 Design and development of data acquisition (DAQ) systems for channeltron and PSD: DAQ software must be written for the purchased DAQ. Two different types of DAQ programs will be used either to scan the spectrometer voltages with the channeltron detector or keep the voltages fixed when used with spectrograph’s position sensitive detector (PSD). Eventually both will be combined in one program.

6.3 Tests of complete electronics and DAQ with pulsers: Tests of the electronics will be performed with pulsers, Eventually, improvements in the counting rate capabilities of the Kansas system [Ben99b] and dead time minimization will be sought using histogramming memory electronics or delay-line electronics

Deliverables:

2 Reports and part of BS, MS or PhD thesis, DAQ software programs

 

Work Package

7

Start:

Month 7

Finish:

Month 18

Cost:

Title:

WP7: Electron spectrometers - preparation, setup and operation

Description:

Research Teams:

RT1, RT2, RT3

7.1 Hemispherical Deflector Analyzer (HDA) - preparation and tests of operation:

7.2 Two-stage 450 parallel plate Analyzer (PPA) - preparation and tests of operation:

Existing HDA [Ben99a, b, Zou02a] and PPA [Zou97a] spectrometers brought from Kansas must be prepared for use, cleaned, resurfaced with conducting graphite coating (Aquadag) and tested for electrical high voltage break down to 5kV. Special positioning stands for both systems allowing for sensitive alignment must be built. Both MCP plates, found to develop dead spots or hot spots after heavy and channeltron detector, deteriorate over time will be replaced as needed, the cost included under consumables.

7.3 Final test of spectrometers -high voltage control and DAQ: Finally, the entire spectroscopy apparatus connected to the DAQ (WP6) will be tested first with an e-gun and later with collisional electrons.  Further improvement of the optics of deceleration stage in either type of spectrometer is also planned using the simulation software SIMION for maximum transmission optimization and improved energy resolution.

Deliverables:

1 Report and part of BS, MS or PhD thesis, DAQ software programs

B. Measurement phase (WP8)

With the end of phase A, we can finally start in WP8 with the proposed measurements using the He-like ions, the installed post strippers, the new beam line and the electron spectroscopy setup. The measurements will be performed using the zero-degree Auger projectile spectroscopy technique [Zou97a], which records the Auger electrons emitted from the projectile ions excited in the collision with the gas target with high resolution in the direction of the beam (00 – zero-degrees).

 

Work Package

8

Start:

Month 19

Finish:

Month 48

Cost:

Title:

WP8: Measurements of electron spectra using ions from the TANDEM

Description:

Research Teams:

RT1, RT2, RT3, RT4

For the specific isoelectronic sequence measurements proposed here we shall follow the procedures presented in Strohschein et al [Stro08a] used for the measured C4+ spectra shown in Figs. 1 and 2. The same procedures will be repeated for every single different ion species used until we cover all the ions with atomic number between Lithium and Fluorine.  These are described below:

8.1 Start up of negative ion source - tuning the beam at the required energy for optimal transmission:

This is the first part of every beam time and includes the startup of the ion source, tuning the selected ion species through the accelerator with the required energy, selecting the right charge state at the analyzing magnet, post stripping if necessary prior to switching the beam to the right beam line by setting the switching magnet. Depending on whether beam in the ground state or mixed state is required, the tank gas stripper or the post-stripper is activated. The selected beam is eventually tuned through the target gas cell and the 00 spectrometer and optimized in the final Faraday cup. Electron spectra are then accumulated and final beam tuning to minimize background from slits etc. is performed.

8.2 Absolute energy calibration of electron spectra

Before projectile electron spectra can be taken an overall electron energy calibration of the entire apparatus is required usually performed with known target Auger lines as for example obtained in 3 MeV p + Ne/Ar [Zou97a]. Also required is the accurate knowledge of the beam velocity which is usually obtained by measuring the energy of the “cusp” electrons which are known to move at the projectile speed. Finally, once this is known, projectile electron spectra can be safely accumulated since the Auger energies in the lab frame are now well specified and particular states/lines can be accurately identified.

8.3. Absolute calibration of electron double differential cross sections (DDCS)

This is an important calibration of the counts scale of an electron spectrum related to the electron DDCS and the overall absolute efficiency of the apparatus. It is typically performed by a procedure well established by Zouros and his collaborators in Kansas. It involves a measurement of the so called Binary Encounter peak electrons using bare ions which correspond to elastically scattered electrons for which the absolute DDCS are very well established from theory. This calibration is usually performed with a strong completely stripped ion beam typically F9+, O8+ or B5+ around 1 MeV/u [Zou97a].

8.4. Measurements of electron spectra and conversion to DDCS

Once the precise energy range of the spectrum to be recorded as well as the target gas pressure are specified after a few standard tests requiring short runs of spectra accumulation, the final high resolution spectra (under electron pre-deceleration)  are accumulated consisting of (a) A spectrum with loaded gas cell, (b) A spectrum with no gas (background spectrum). The subtraction of (b) from (a) will give the necessary “clean” or background subtracted spectrum.

This procedure is repeated for all required spectra for both types of He-like beams, i.e. the “pure” ground state beams taken using the terminal gas stripper and the mixed 1s2/1s2s 3S beams taken using a foil post-stripper. Such spectra will be taken for both H2 and He targets and possibly for other gas targets such as CH4, Ne or Ar, having more than 2 electrons to be captured, as an extra test. Total high statistics accumulation time for each spectrum can vary between 1 and 4 hours depending on beam intensity.

8.5. Servicing of experimental components after use

The electron spectrometers with their detectors are normally kept in the collision chamber under vacuum even when not used for measurements since this preserves them in a clean environment and extends the life time of the MCP plates and channeltron detectors. However, after some use the MCPs eventually deteriorate and need to be replaced about once a year, depending on use. Similarly, for channeltrons, which however being more rugged, need replacement only once every 2 years. Spectrometers also sometimes, especially if a vacuum accident occurs, need meticulous cleaning and even high voltage conditioning. Graphite coating must also be refreshed every so often, especially if the spectrometer needs to be taken apart for cleaning which is a major operation. Both Prof. Benis and Zouros have done this procedure many times.

8.6. Back-up of all data on special storage media

In a typical run many different spectra are collected. Especially the two-dimensional images of the 2-D PSD require a lot more disk space on the PC. The data of each run will be backed up onto a special hard disk, labeled and logged so it can be readily accessed for future offline data analysis.

Deliverables:

2 Reports, part of BS, MS or PhD thesis

C. Data analysis and dissemination phase (WP9-WP10)

After the first few measurements we shall start the data analysis and the dissemination of the results first within the local groups and then on a more international scale.

Work Package

9

Start:

Month 19

Finish:

Month 48

Cost:

Title:

WP9: Analysis and presentation of new results

Description:

Research Teams:

RT1, RT2, RT3, RT4

9.1 Homebuilt Software for data analysis: Typical data analysis has to do with fitting Auger lines (with specialized peak fitting software) and extracting the absolute single and double differential cross sections as a function of collision energy. The technique of 00Auger projectile spectroscopy is well known for its ability to obtain such results for each state, as long as the observed states are well resolved in the spectra. This allows for very stringent tests of theory

9.2 Analysis of all data: Total production cross sections will also be determined using theoretical structure information (usually Hartree-Fock codes like Cowan’s etc. [Zou08a]) for the Auger yield and the angular distribution probability.

9.3 Presentation of new results within research groups: From the determined cross sections for the 4P and the 2P lines we shall eventually extract a value for the ratio R as a function of collision energy. Cascade contributions will be computed using various codes already developed by Zouros and Sulik [Zou08a].

9.4 Discussions of new results - reevaluation of what to measure: We also have extensive contact with theorists who will be interested to compare their calculations to our new data.

Deliverables:

1 Report and part of BS, MS or PhD thesis, software data analysis programs

 

Work Package

10

Start:

Month 22

Finish:

Month 48

Cost:

Title:

WP10: Dissemination of new results worldwide

Description:

Research Teams:

RT1, RT2, RT3, RT4

10.1          Final technical reports with summary of measurements and results:

10.2 Publications in international scientific journals of the field: The dissemination of our new results will be accomplished primarily by scientific publications in well known international journals of high impact factor such as Physical Review (Letters, A: Rapid Communications, Α: Papers), Journal of Physics B (Letters, Papers), Journal of Electron Spectroscopy and Related Phenomena, Nuclear Instruments and Methods in Physics Research A και B, Physica Scripta, Review of Scientific Instruments, International Journal of Mass Spectrometry etc..

10.3 Participation in international conferences - presentations: Also by presentations at meetings, seminars and international conferences such as:

  • ICPEAC (Int. Conf. on the Physics of Photonic, Electronic and Atomic Collisions) (2013,2015)
  • ISIAC (International Symposium on Ion Atom Collisions) (2013,2015)
  • HCI (international conference on the physics of Highly Charged Ions) (2012,2014,2016)
  • CAARI (Int. Conference on the Applications of Accelerators in Research and Industry) (2012,2014)

Deliverables:

2 Reports, 3 BS, 2 MS, 1 PhD thesis, >15 publications, >20 posters, >3 talks at conferences

 

Work Package

11

Start:

Month 1

Finish:

Month 48

Cost:

Title:

WP11: Project Administration

Description:

Research Teams:

RT1

Over the entire 48 month duration the project coordinator will be in charge of:

11.1 Organization, advertising, interviewing, monitoring, coordination, report and paper writing:

11.2 Website administration

Deliverables:

3 Reports, Website

Last Update: 29/01/14 23:57:20

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