A Test of Quantum Electrodynamics at High Fields View Homepage


Ontology type: schema:MonetaryGrant     


Grant Info

YEARS

2007-2010

FUNDING AMOUNT

507185 GBP

ABSTRACT

Quantum electrodynamics (QED) was the first quantum field theory to be formulated providing a radically new description of the electromagnetic force. So far it has successfully passed every experimental test at low and intermediate fields. A well-known example of QED effects at low fields, of the order of 10^9 V/cm, is the Lamb shift in hydrogen. At such low fields, the QED effects can still be treated perturbatively, only taking into account low order terms. However, up to now QED has never been tested at very much higher fields than this because of the practical difficulties of producing such fields in the laboratory. At high fields, perturbative QED is no longer valid, and higher order terms need to be evaluated carefully. Experiments carried out at high fields therefore test different aspects of QED and are complementary to high precision tests of the low order terms. Since quantum field theories are the cornerstone of modern physics testing these theories in the non-perturbative limit is extremely important. Heavy atoms that have been stripped of almost all their electrons are ideal 'laboratories' for tests of QED at high fields. These ions have electric field strengths of the order of 10^15 V/cm close to the nucleus. Such highly charged ions (HCI) can now be produced at the experimental storage ring (ESR) at GSI in Darmstadt, Germany. In the HITRAP facility being built at GSI, these ions will be slowed, trapped and cooled down to sub-eV energies, and made available to a wide variety of experiments. Our group has been involved in the planning stages of this facility and it has been our responsibility to design the laser spectroscopy experiments to test QED at high fields. The early stages of this work have been funded through a European Union FP5 collaboration (also called HITRAP). Now that the completion of the facility is in sight the various groups involved must seek funding at the national level to complete the project. Hydrogen-like (one electron) and lithium-like (three electrons) highly charged ions in particular are excellent examples of systems that allow for accurate studies of QED effects at high fields. The ground state hyperfine splitting (HFS) in these species probes the validity of QED at the extremely high fields found very close to the nucleus. Due to their simple electronic structure, accurate QED calculations can be performed for these systems, which could be compared for the first time with the accurate experimental results we wish to obtain. The only proposed method of disentangling the QED effects from nuclear effects, such as the Bohr-Weisskopf (BW) effect, is by measuring the ground state HFS in both H-like and Li-like ions. From the difference between these two HFS the BW effect can effectively be eliminated. This allows for a determination of the QED effects with an accuracy of the order of a few percent. In neutral atoms hyperfine transitions are weak transitions in the microwave region of the spectrum. In (HCI) the electric fields involved push these transitions into the visible region of the spectrum and increase their transition rates. H- and Li-like bismuth ions are of interest because the wavelengths corresponding to these hyperfine transitions are both accessible with standard lasers. A common experimental obstacle in previous measurements made in a storage ring was the Doppler width and shift of the transition due to the relativistic velocities of the ions. Other measurements performed in an EBIT (electron beam ion trap) are not as severely subject to this effect, but suffer from a low signal-to-background ratio. We propose to trap highly charged ions in a Penning trap, cool and compress the ions into a small cloud, and measure ground state hyperfine splittings by means of laser spectroscopy, with an accuracy of the order of 10-7. Preparatory work will be performed at Imperial College but the final experiments will be performed at the HITRAP facility in Germany. More... »

URL

http://gtr.rcuk.ac.uk/project/E856BB57-AB93-453C-A461-68BAA81DFEF1

JSON-LD is the canonical representation for SciGraph data.

TIP: You can open this SciGraph record using an external JSON-LD service: JSON-LD Playground Google SDTT

[
  {
    "@context": "https://springernature.github.io/scigraph/jsonld/sgcontext.json", 
    "about": [
      {
        "id": "http://purl.org/au-research/vocabulary/anzsrc-for/2008/2202", 
        "inDefinedTermSet": "http://purl.org/au-research/vocabulary/anzsrc-for/2008/", 
        "type": "DefinedTerm"
      }, 
      {
        "id": "http://purl.org/au-research/vocabulary/anzsrc-for/2008/2202", 
        "inDefinedTermSet": "http://purl.org/au-research/vocabulary/anzsrc-for/2008/", 
        "type": "DefinedTerm"
      }
    ], 
    "amount": {
      "currency": "GBP", 
      "type": "MonetaryAmount", 
      "value": "507185"
    }, 
    "description": "Quantum electrodynamics (QED) was the first quantum field theory to be formulated providing a radically new description of the electromagnetic force. So far it has successfully passed every experimental test at low and intermediate fields. A well-known example of QED effects at low fields, of the order of 10^9 V/cm, is the Lamb shift in hydrogen. At such low fields, the QED effects can still be treated perturbatively, only taking into account low order terms. However, up to now QED has never been tested at very much higher fields than this because of the practical difficulties of producing such fields in the laboratory. At high fields, perturbative QED is no longer valid, and higher order terms need to be evaluated carefully. Experiments carried out at high fields therefore test different aspects of QED and are complementary to high precision tests of the low order terms. Since quantum field theories are the cornerstone of modern physics testing these theories in the non-perturbative limit is extremely important. Heavy atoms that have been stripped of almost all their electrons are ideal 'laboratories' for tests of QED at high fields. These ions have electric field strengths of the order of 10^15 V/cm close to the nucleus. Such highly charged ions (HCI) can now be produced at the experimental storage ring (ESR) at GSI in Darmstadt, Germany. In the HITRAP facility being built at GSI, these ions will be slowed, trapped and cooled down to sub-eV energies, and made available to a wide variety of experiments. Our group has been involved in the planning stages of this facility and it has been our responsibility to design the laser spectroscopy experiments to test QED at high fields. The early stages of this work have been funded through a European Union FP5 collaboration (also called HITRAP). Now that the completion of the facility is in sight the various groups involved must seek funding at the national level to complete the project. Hydrogen-like (one electron) and lithium-like (three electrons) highly charged ions in particular are excellent examples of systems that allow for accurate studies of QED effects at high fields. The ground state hyperfine splitting (HFS) in these species probes the validity of QED at the extremely high fields found very close to the nucleus. Due to their simple electronic structure, accurate QED calculations can be performed for these systems, which could be compared for the first time with the accurate experimental results we wish to obtain. The only proposed method of disentangling the QED effects from nuclear effects, such as the Bohr-Weisskopf (BW) effect, is by measuring the ground state HFS in both H-like and Li-like ions. From the difference between these two HFS the BW effect can effectively be eliminated. This allows for a determination of the QED effects with an accuracy of the order of a few percent. In neutral atoms hyperfine transitions are weak transitions in the microwave region of the spectrum. In (HCI) the electric fields involved push these transitions into the visible region of the spectrum and increase their transition rates. H- and Li-like bismuth ions are of interest because the wavelengths corresponding to these hyperfine transitions are both accessible with standard lasers. A common experimental obstacle in previous measurements made in a storage ring was the Doppler width and shift of the transition due to the relativistic velocities of the ions. Other measurements performed in an EBIT (electron beam ion trap) are not as severely subject to this effect, but suffer from a low signal-to-background ratio. We propose to trap highly charged ions in a Penning trap, cool and compress the ions into a small cloud, and measure ground state hyperfine splittings by means of laser spectroscopy, with an accuracy of the order of 10-7. Preparatory work will be performed at Imperial College but the final experiments will be performed at the HITRAP facility in Germany.", 
    "endDate": "2010-06-29T23:00:00Z", 
    "funder": {
      "id": "https://www.grid.ac/institutes/grid.421091.f", 
      "type": "Organization"
    }, 
    "id": "sg:grant.2783705", 
    "identifier": [
      {
        "name": "dimensions_id", 
        "type": "PropertyValue", 
        "value": [
          "2783705"
        ]
      }, 
      {
        "name": "gtr_id", 
        "type": "PropertyValue", 
        "value": [
          "E856BB57-AB93-453C-A461-68BAA81DFEF1"
        ]
      }
    ], 
    "inLanguage": [
      "en"
    ], 
    "keywords": [
      "experimental storage ring", 
      "transition rates", 
      "excellent example", 
      "quantum electrodynamics", 
      "validity", 
      "project", 
      "laboratory", 
      "such fields", 
      "such low fields", 
      "transition", 
      "preparatory work", 
      "few percent", 
      "new description", 
      "lower order terms", 
      "final experiment", 
      "high field", 
      "previous measurements", 
      "Imperial College", 
      "High Fields", 
      "system", 
      "planning stage", 
      "high precision tests", 
      "first quantum field theory", 
      "different aspects", 
      "electric field strength", 
      "Germany", 
      "hyperfine transitions", 
      "HITRAP facility", 
      "HCI", 
      "completion", 
      "GSI", 
      "weak transitions", 
      "background ratio", 
      "QED effects", 
      "modern physics", 
      "groups", 
      "account", 
      "ions", 
      "electromagnetic force", 
      "effect", 
      "hydrogen", 
      "measure ground state hyperfine splittings", 
      "experimental tests", 
      "responsibility", 
      "neutral atoms", 
      "low signal", 
      "standard laser", 
      "electric field", 
      "METHODS", 
      "EBIT", 
      "wavelength", 
      "heavy atoms", 
      "Doppler width", 
      "low fields", 
      "simple electronic structure", 
      "laser spectroscopy", 
      "intermediate fields", 
      "microwave region", 
      "BW effect", 
      "accurate experimental results", 
      "electron beam ion trap", 
      "means", 
      "accuracy", 
      "Li-like ions", 
      "interest", 
      "ground state hyperfine splitting", 
      "accurate QED calculation", 
      "test", 
      "nucleus", 
      "early stages", 
      "shift", 
      "electron", 
      "perturbative QED", 
      "differences", 
      "HiTrap", 
      "national level", 
      "Lamb shift", 
      "Penning trap", 
      "quantum field theory", 
      "sub-eV energies", 
      "relativistic velocities", 
      "determination", 
      "theory", 
      "cornerstone", 
      "work", 
      "order", 
      "European Union FP5 collaboration", 
      "common experimental obstacle", 
      "first time", 
      "laser spectroscopy experiments", 
      "nuclear effects", 
      "higher order terms", 
      "wide variety", 
      "other measurements", 
      "facilities", 
      "BW", 
      "spectrum", 
      "visible region", 
      "Quantum Electrodynamics", 
      "example", 
      "small clouds", 
      "ground state hfs", 
      "sight", 
      "experiments", 
      "funding", 
      "practical difficulties", 
      "lithium", 
      "species probes", 
      "Darmstadt", 
      "accurate study", 
      "Li-like bismuth ions", 
      "various groups", 
      "H-", 
      "non-perturbative limit", 
      "storage ring"
    ], 
    "name": "A Test of Quantum Electrodynamics at High Fields", 
    "recipient": [
      {
        "id": "https://www.grid.ac/institutes/grid.7445.2", 
        "type": "Organization"
      }, 
      {
        "affiliation": {
          "id": "https://www.grid.ac/institutes/grid.7445.2", 
          "name": "Imperial College London", 
          "type": "Organization"
        }, 
        "familyName": "Thompson", 
        "givenName": "Richard", 
        "id": "sg:person.011574064625.08", 
        "type": "Person"
      }, 
      {
        "member": "sg:person.011574064625.08", 
        "roleName": "PI", 
        "type": "Role"
      }, 
      {
        "affiliation": {
          "id": "https://www.grid.ac/institutes/grid.7445.2", 
          "name": "Imperial College London", 
          "type": "Organization"
        }, 
        "familyName": "Segal", 
        "givenName": "Daniel", 
        "id": "sg:person.01360175240.35", 
        "type": "Person"
      }, 
      {
        "member": "sg:person.01360175240.35", 
        "roleName": "Co-PI", 
        "type": "Role"
      }
    ], 
    "sameAs": [
      "https://app.dimensions.ai/details/grant/grant.2783705"
    ], 
    "sdDataset": "grants", 
    "sdDatePublished": "2019-03-07T11:34", 
    "sdLicense": "https://scigraph.springernature.com/explorer/license/", 
    "sdPublisher": {
      "name": "Springer Nature - SN SciGraph project", 
      "type": "Organization"
    }, 
    "sdSource": "s3://com.uberresearch.data.processor/core_data/20181219_192338/projects/base/gtr_projects_3.xml.gz", 
    "startDate": "2007-05-31T23:00:00Z", 
    "type": "MonetaryGrant", 
    "url": "http://gtr.rcuk.ac.uk/project/E856BB57-AB93-453C-A461-68BAA81DFEF1"
  }
]
 

Download the RDF metadata as:  json-ld nt turtle xml License info

HOW TO GET THIS DATA PROGRAMMATICALLY:

JSON-LD is a popular format for linked data which is fully compatible with JSON.

curl -H 'Accept: application/ld+json' 'https://scigraph.springernature.com/grant.2783705'

N-Triples is a line-based linked data format ideal for batch operations.

curl -H 'Accept: application/n-triples' 'https://scigraph.springernature.com/grant.2783705'

Turtle is a human-readable linked data format.

curl -H 'Accept: text/turtle' 'https://scigraph.springernature.com/grant.2783705'

RDF/XML is a standard XML format for linked data.

curl -H 'Accept: application/rdf+xml' 'https://scigraph.springernature.com/grant.2783705'


 

This table displays all metadata directly associated to this object as RDF triples.

168 TRIPLES      19 PREDICATES      139 URIs      130 LITERALS      6 BLANK NODES

Subject Predicate Object
1 sg:grant.2783705 schema:about anzsrc-for:2202
2 schema:amount N7a94b457986041f987c5b2cf72cff3ea
3 schema:description Quantum electrodynamics (QED) was the first quantum field theory to be formulated providing a radically new description of the electromagnetic force. So far it has successfully passed every experimental test at low and intermediate fields. A well-known example of QED effects at low fields, of the order of 10^9 V/cm, is the Lamb shift in hydrogen. At such low fields, the QED effects can still be treated perturbatively, only taking into account low order terms. However, up to now QED has never been tested at very much higher fields than this because of the practical difficulties of producing such fields in the laboratory. At high fields, perturbative QED is no longer valid, and higher order terms need to be evaluated carefully. Experiments carried out at high fields therefore test different aspects of QED and are complementary to high precision tests of the low order terms. Since quantum field theories are the cornerstone of modern physics testing these theories in the non-perturbative limit is extremely important. Heavy atoms that have been stripped of almost all their electrons are ideal 'laboratories' for tests of QED at high fields. These ions have electric field strengths of the order of 10^15 V/cm close to the nucleus. Such highly charged ions (HCI) can now be produced at the experimental storage ring (ESR) at GSI in Darmstadt, Germany. In the HITRAP facility being built at GSI, these ions will be slowed, trapped and cooled down to sub-eV energies, and made available to a wide variety of experiments. Our group has been involved in the planning stages of this facility and it has been our responsibility to design the laser spectroscopy experiments to test QED at high fields. The early stages of this work have been funded through a European Union FP5 collaboration (also called HITRAP). Now that the completion of the facility is in sight the various groups involved must seek funding at the national level to complete the project. Hydrogen-like (one electron) and lithium-like (three electrons) highly charged ions in particular are excellent examples of systems that allow for accurate studies of QED effects at high fields. The ground state hyperfine splitting (HFS) in these species probes the validity of QED at the extremely high fields found very close to the nucleus. Due to their simple electronic structure, accurate QED calculations can be performed for these systems, which could be compared for the first time with the accurate experimental results we wish to obtain. The only proposed method of disentangling the QED effects from nuclear effects, such as the Bohr-Weisskopf (BW) effect, is by measuring the ground state HFS in both H-like and Li-like ions. From the difference between these two HFS the BW effect can effectively be eliminated. This allows for a determination of the QED effects with an accuracy of the order of a few percent. In neutral atoms hyperfine transitions are weak transitions in the microwave region of the spectrum. In (HCI) the electric fields involved push these transitions into the visible region of the spectrum and increase their transition rates. H- and Li-like bismuth ions are of interest because the wavelengths corresponding to these hyperfine transitions are both accessible with standard lasers. A common experimental obstacle in previous measurements made in a storage ring was the Doppler width and shift of the transition due to the relativistic velocities of the ions. Other measurements performed in an EBIT (electron beam ion trap) are not as severely subject to this effect, but suffer from a low signal-to-background ratio. We propose to trap highly charged ions in a Penning trap, cool and compress the ions into a small cloud, and measure ground state hyperfine splittings by means of laser spectroscopy, with an accuracy of the order of 10-7. Preparatory work will be performed at Imperial College but the final experiments will be performed at the HITRAP facility in Germany.
4 schema:endDate 2010-06-29T23:00:00Z
5 schema:funder https://www.grid.ac/institutes/grid.421091.f
6 schema:identifier N01cdd91ba5354717b44e3e75f719bc16
7 N7e6726ad11194eeabc84875d731e8cfc
8 schema:inLanguage en
9 schema:keywords BW
10 BW effect
11 Darmstadt
12 Doppler width
13 EBIT
14 European Union FP5 collaboration
15 GSI
16 Germany
17 H-
18 HCI
19 HITRAP facility
20 HiTrap
21 High Fields
22 Imperial College
23 Lamb shift
24 Li-like bismuth ions
25 Li-like ions
26 METHODS
27 Penning trap
28 QED effects
29 Quantum Electrodynamics
30 account
31 accuracy
32 accurate QED calculation
33 accurate experimental results
34 accurate study
35 background ratio
36 common experimental obstacle
37 completion
38 cornerstone
39 determination
40 differences
41 different aspects
42 early stages
43 effect
44 electric field
45 electric field strength
46 electromagnetic force
47 electron
48 electron beam ion trap
49 example
50 excellent example
51 experimental storage ring
52 experimental tests
53 experiments
54 facilities
55 few percent
56 final experiment
57 first quantum field theory
58 first time
59 funding
60 ground state hfs
61 ground state hyperfine splitting
62 groups
63 heavy atoms
64 high field
65 high precision tests
66 higher order terms
67 hydrogen
68 hyperfine transitions
69 interest
70 intermediate fields
71 ions
72 laboratory
73 laser spectroscopy
74 laser spectroscopy experiments
75 lithium
76 low fields
77 low signal
78 lower order terms
79 means
80 measure ground state hyperfine splittings
81 microwave region
82 modern physics
83 national level
84 neutral atoms
85 new description
86 non-perturbative limit
87 nuclear effects
88 nucleus
89 order
90 other measurements
91 perturbative QED
92 planning stage
93 practical difficulties
94 preparatory work
95 previous measurements
96 project
97 quantum electrodynamics
98 quantum field theory
99 relativistic velocities
100 responsibility
101 shift
102 sight
103 simple electronic structure
104 small clouds
105 species probes
106 spectrum
107 standard laser
108 storage ring
109 sub-eV energies
110 such fields
111 such low fields
112 system
113 test
114 theory
115 transition
116 transition rates
117 validity
118 various groups
119 visible region
120 wavelength
121 weak transitions
122 wide variety
123 work
124 schema:name A Test of Quantum Electrodynamics at High Fields
125 schema:recipient N729d0da5a0d24446a6ca0b8ede6936ca
126 N7c1e9d20638d4d2f882db987b20c6ab9
127 sg:person.011574064625.08
128 sg:person.01360175240.35
129 https://www.grid.ac/institutes/grid.7445.2
130 schema:sameAs https://app.dimensions.ai/details/grant/grant.2783705
131 schema:sdDatePublished 2019-03-07T11:34
132 schema:sdLicense https://scigraph.springernature.com/explorer/license/
133 schema:sdPublisher N98d1daae23f24b18ac48f1c55e456a37
134 schema:startDate 2007-05-31T23:00:00Z
135 schema:url http://gtr.rcuk.ac.uk/project/E856BB57-AB93-453C-A461-68BAA81DFEF1
136 sgo:license sg:explorer/license/
137 sgo:sdDataset grants
138 rdf:type schema:MonetaryGrant
139 N01cdd91ba5354717b44e3e75f719bc16 schema:name gtr_id
140 schema:value E856BB57-AB93-453C-A461-68BAA81DFEF1
141 rdf:type schema:PropertyValue
142 N729d0da5a0d24446a6ca0b8ede6936ca schema:member sg:person.01360175240.35
143 schema:roleName Co-PI
144 rdf:type schema:Role
145 N7a94b457986041f987c5b2cf72cff3ea schema:currency GBP
146 schema:value 507185
147 rdf:type schema:MonetaryAmount
148 N7c1e9d20638d4d2f882db987b20c6ab9 schema:member sg:person.011574064625.08
149 schema:roleName PI
150 rdf:type schema:Role
151 N7e6726ad11194eeabc84875d731e8cfc schema:name dimensions_id
152 schema:value 2783705
153 rdf:type schema:PropertyValue
154 N98d1daae23f24b18ac48f1c55e456a37 schema:name Springer Nature - SN SciGraph project
155 rdf:type schema:Organization
156 anzsrc-for:2202 schema:inDefinedTermSet anzsrc-for:
157 rdf:type schema:DefinedTerm
158 sg:person.011574064625.08 schema:affiliation https://www.grid.ac/institutes/grid.7445.2
159 schema:familyName Thompson
160 schema:givenName Richard
161 rdf:type schema:Person
162 sg:person.01360175240.35 schema:affiliation https://www.grid.ac/institutes/grid.7445.2
163 schema:familyName Segal
164 schema:givenName Daniel
165 rdf:type schema:Person
166 https://www.grid.ac/institutes/grid.421091.f schema:Organization
167 https://www.grid.ac/institutes/grid.7445.2 schema:name Imperial College London
168 rdf:type schema:Organization
 




Preview window. Press ESC to close (or click here)


...