This document discusses various methods for detecting neutrinos. It is very difficult to detect neutrinos due to their weak interactions. The earliest detection was through inverse beta decay using a nuclear reactor. Later, the Sudbury Neutrino Observatory was able to detect neutrinos via different interactions in deuterium, providing evidence of neutrino flavor oscillations. Now, large detectors like IceCube are detecting high-energy neutrinos from astrophysical sources. Measuring the neutrino mass precisely remains challenging but various techniques using beta decay spectra provide upper limits.
From my class on nuclear physics for nuclear medicine technologists. This class covers alpha, beta, and gamma decay, plus conversion electrons, Auger electrons, and k-alpha and other X-rays
origin of quantum physics -
Inadequacy of classical mechanics and birth of QUANTUM PHYSICS
ref: Quantum mechanics: concepts and applications, N. Zettili
We present an ab-initio real-time based computational approach to nonlinear optical properties in Condensed Matter systems. The equation of mot ions, and in particular the coupling of the electrons with the external electric field, are derived from the Berry phase formulation of the dynamical polarization. The zero-field Hamiltonian includes crystal local field effects, the renormalization of the independent particle energy levels by correlation and excitonic effects within the screened Hartree- Fock self-energy operator. The approach is validated by calculating the second-harmonic generation of SiC and AlAs bulk semiconductors : an excellent agreement is obtained with existing ab-initio calculations from response theory in frequency domain . We finally show applications to the second-harmonic generation of CdTe the third-harmonic generation of Si.
Reference :
Real-time approach to the optical properties of solids and nanostructures : Time-dependent Bethe-alpeter equation Phys. Rev. B 84, 245110 (2011)
Nonlinear optics from ab-initio by means of the dynamical Berry-phase
C. Attaccalite and M. Gruning Phys. Rev. B 88 (23), 235113 (2013)
From my class on nuclear physics for nuclear medicine technologists. This class covers alpha, beta, and gamma decay, plus conversion electrons, Auger electrons, and k-alpha and other X-rays
origin of quantum physics -
Inadequacy of classical mechanics and birth of QUANTUM PHYSICS
ref: Quantum mechanics: concepts and applications, N. Zettili
We present an ab-initio real-time based computational approach to nonlinear optical properties in Condensed Matter systems. The equation of mot ions, and in particular the coupling of the electrons with the external electric field, are derived from the Berry phase formulation of the dynamical polarization. The zero-field Hamiltonian includes crystal local field effects, the renormalization of the independent particle energy levels by correlation and excitonic effects within the screened Hartree- Fock self-energy operator. The approach is validated by calculating the second-harmonic generation of SiC and AlAs bulk semiconductors : an excellent agreement is obtained with existing ab-initio calculations from response theory in frequency domain . We finally show applications to the second-harmonic generation of CdTe the third-harmonic generation of Si.
Reference :
Real-time approach to the optical properties of solids and nanostructures : Time-dependent Bethe-alpeter equation Phys. Rev. B 84, 245110 (2011)
Nonlinear optics from ab-initio by means of the dynamical Berry-phase
C. Attaccalite and M. Gruning Phys. Rev. B 88 (23), 235113 (2013)
Trabajo Final de Grado Física(UV): Angular distribution and energy spectrum o...Christiaan Roca Catala
Thesis of my bachellor in Physics.
We analise the angular distribution and the energy spectrum of neutrinos coming from decaying pions in a boosted frame. From this we observe the benefits of placing a detector at an off-axis angle respect to the trajectory of the pion.
In concrete we derive the effects of adding first order corrections to the mass of the initially set massless neutrino in the kinematical scheme. We compare the results with the well-known biography and determine that those corrections lead no contribution.
Finally we discuss the importance of this scheme on the neutrino experiments nowadays. A higher detection rate leads better results on the actual detections. In a near future this could shed some light on some of the most elusive problems nowadays in neutrino physics. For example, the neutrino mass hierarchy or the CP violation in the leptonic sector.
We pay special attention to the recent results of T2K (Tokai to Kamioka) and NOvA.
Norman John Brodeur worked at MIT’s instrumentation lab which later became Draper Labs. My responsibility was instrumentation and guidance systems for the Apollo command module and the lunar module. Previous to that I worked for Avco-Everett Research Lab in Everett. There we focused on testing materials for the vehicle’s heat shield. I was doing heat studies of various materials and what we eventually developed would just burn off and the heat with it.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
2. Neutrino Sources
2
Most neutrino sources are natural (not from accelerators and reactors)
Figure from https://masterclass.icecube.wisc.edu/en/learn/detecting-neutrinos
• Huge flux
• Broad energy range
3. Why is it so hard to detect neutrinos?
3
Neutrinos participate only in weak interactions
Formaggio and Zeller, Rev. Mod. Phys. 84, 1307 (2012)
[10-27cm2]
4. Why is it so hard to detect neutrinos?
4
λ =
1
ρσ
σ ∼ 10−43
cm2 @1 MeV
ρ =
(82 e/atom)(11.3 g/cm3
)(6.02 × 1023
atom/mole)
(207 g/mole)
= 2.7 × 1024
e/cm3
λ ∼ 4 × 1016
m = 4 light years
attenuation length
• Look for its decay?
(AFAIK) Neutrinos don’t decay
• Look for its interactions?
Ex: 1-MeV scattering off atomic electrons in Pb:¯νe
Need:
HUGE flux
HUGE target
5. An explosive idea - Reines and Cowan
5
- Fred Reines
Reines and Cowan scrapped this idea.
6. Discovery of the (Anti-)Neutrinos
6
€
νefrom reactor
p
e+
511 keV γ
511 keV γ
e+e- annihilationn
γγ
γ’s from n
capture on
Cd
Cd
Liquid Scintillator
γ
Liquid Scintillator
H2O+CdCl2
• F. Reines & C.L. Cowan [Physical Review 117, 160 (1960)]
• Detection at Savannah River reactor plant
Inverse Beta Decay
¯νe + p → n + e+
9. Neutrino-electron scattering
9
Tree level diagrams:
Targets have a lot of atomic electrons
Charged Current (CC) Neutral Current (NC)
νe, νμ, ντνe only
ℒ = −
GF
2
[¯νeγμ
(1 −γ5
)e][¯eγμ(1 −γ5
)νe] + [¯νeγμ
(1 −γ5
)νe][¯eγμ(ge
V −ge
Aγ5
)e)]
10. Neutrino-electron scattering
10
Tree level diagrams:
Targets have a lot of atomic electrons
Charged Current (CC) Neutral Current (NC)
νe, νμ, ντνe only
gL = sin2
θW ± e
μ,τ
1
2
gR = sin2
θW
gL ↔ gR for ¯ν
σ =
2G2
Fme
π
[(g2
L +
g2
R
3
Eν) −
gLgR
2
me]
11. Neutrino-electron scattering
11
νe
νe
e
e
θ
(Te, ⃗pe)
(Eν, ⃗pν)
Te =
2meE2
ν cos2
θ
(me + Eν)2 − E2
ν cos2 θ
• Electron emitted at very small angle
with respect to the neutrino direction Eeθ2
e ≤ 2me:
Solar neutrino image
Solar neutrinos
12. Cherenkov radiation - seeing relativistic charged particles
12
Graphics from http://physicsopenlab.org/
cos θC =
1
βn
θC = 41∘
in H2O (β~1)
Event in SNO
Cherenkov light is emitted when a charged
particle passes through a dielectric medium
at a speed higher than the speed of light in
that medium.
13. Coherent Elastic Neutrino-Nucleus Scattering
13
• When q << 1/R (Eν < 50 MeV),
σTotal ~ N2, but the nucleus recoil
energy is very low.
• First observation was made in a
CsI detector using neutrinos from
the Spallation Neutron Source at
ORNL.
D. Akimov et al., Science 10.1126/science.aao0990 (2017).
electron
CEνNS
17. Inverse Beta Decay (IBD)
• Recall (the discovery of neutrinos by Reines & Cowan):
• The cross section of this process at low neutrino energy (~ a few MeV) is:
where f = 1.715 and τn = 880.2 (1.0) s
(but with controversial measurements).
• The neutron lifetime is an important
parameter that fixes the cross section
for single nucleon processes.
17
Inverse Beta Decay: ¯νe + p → n + e+
σtot =
2π2
m5
e
Ee+ pe+
fτn
E¯νe
> 1.8 MeV
PDG 2017
18. Geo-neutrinos
• 1 kt liquid scintillator
• Detect anti-neutrinos from reactors and
earth’s core by IBD
18 Shirahata 2017
19. Using other nuclei as neutrino target
• The first detection of solar neutrinos by Ray Davis (615t of C2Cl4 at
Homestake mine (now SURF) in SD:
19
νe + 37Cl → 37Ar + e−
(Eν > 0.814 MeV)
• Flushed tank, collected 37Ar, looked for its
decay back to 37Cl.
• Solar Neutrino Problem: only 1/3 of the
expected number of solar neutrinos was
observed.
• Ray Davis won the Nobel Prize in Physics
(with M. Koshiba) in 2002.
• Note:
• The Sun only emits (p-p chain)
• Charged-current (in detection) only
sensitive to
νe
νe
20. Solar Neutrino Problem (~2000)
• Are the Standard Solar Model predictions wrong?
• Or is there something about the neutrinos that we don’t understand?
20
21. Measure CC and NC (νe vs all flavors)
21
CC
NC
=
νe
νe + νµ +ντ
CC
ES
=
νe
νe + 0.15(νµ + ντ )
φCC
(νe ) < φNC
(νx )
φCC
(νe ) < φES
(νx )
Transformation to another
active flavor if:
Measure:
Alternatively…
Flavor transformation (particle physics) can be tested without any
assumption on the Standard Solar Model prediction of the total neutrino flux.
Is there a magic target ?
22. The deuteron
22
CC
NC
ES
νe + d → p + p + e−
νx + d → p + n + ν′x
νx + e−
→ νx + e−
•2 km underground at Vale’s Creighton
mine near Sudbury, ON, Canada
•1000t of D2O in a 12-m φ acrylic sphere
23. Sudbury Neutrino Observatory (SNO)
23
SNO provided the first direct observation of neutrino flavor transformation
(which requires neutrinos to be massive)
24. • A weak eigenstate is a linear combination of mass eigenstates :
where U = Maki-Nakagawa-Sakata-Pontecorvo (MNSP) matrix.
Aside: neutrino mixing
| | i
| =
3
i=1
U i| i
|U| =
0
@
0.779 $ 0.848 0.510 $ 0.604 0.122 $ 0.190
0.183 $ 0.568 0.385 $ 0.728 0.613 $ 0.794
0.200 $ 0.576 0.408 $ 0.742 0.589 $ 0.775
1
A
|⌫ei = (⇠ 0.81) |⌫1i + (⇠ 0.55) |⌫2i + (⇠ 0.16) |⌫3i
|⌫µi = (⇠ 0.38) |⌫1i + (⇠ 0.56) |⌫2i + (⇠ 0.70) |⌫3i
|⌫⌧ i = (⇠ 0.39) |⌫1i + (⇠ 0.58) |⌫2i + (⇠ 0.68) |⌫3i
25. KamLAND - Reactor Anti-Neutrino
KamLAND showed that neutrino oscillation is the origin of flavor
transformation seen in SNO
25
Nobs/Nno
prediction:
Δm2 = 5.5x10-5 eV2
sin2 2θ = 0.833
P⌫e!⌫e
= 1 sin2
2✓ sin2
✓
1.27
m2
[eV2
] L[m]
E[MeV]
◆
26. Other nuclear targets for ν detection
• A common target is liquid scintillator (lots of C and H), but there have been
other nuclei that have been studied quite extensively
• Theory vs experimental cross section agreement generally good for low
energy (1-300 MeV)
26
28. Atmospheric ν problem (before 1998)
28
Expect Rμ/e: (νµ + νµ) / (νe + νe ) ~ 2
Measured ~ 0.6-0.7 of expectation
π+ → µ+ + νµ
e+ + νe + νµ
π− → µ− + νµ
e− + νe + νµ
Much higher energy
than solar neutrinos
29. Intermediate-energy neutrino cross section
• The nucleus is typically described in terms of individual quasi-free nucleons
that participate in the scattering process
29
νμ N → μ−
X
¯νμ N → μ+
X
1. Quasielastic scattering (QE)
• Example: ,
• Final-state nucleon usually invisible in water
Cherenkov detector
νμ n → μ−
p ¯νμ p → μ+
n
2. Resonant (RES)
• Neutrino interaction produces a baryon
resonance, which quickly decays and
most often to a nucleon and single pion
final state:
νμ N → μ−
N* ; N* → π N′
3. Deep Inelastic Scattering (DIS)
• Both CC and NC possible
• Example:
ν + q → l−
q ′; q ′ → hadrons
4. NC Neutrino-Nucleon Interactions
ν + N → ν + X
30. The axial mass MA puzzle
QE scattering at O(GeV) needs to take into account the nucleon structure:
30
jμ
= [FV
1 (Q2
)γμ
+ i
κ
2M
FV
2 (Q2
)σμν
q ν − FA(Q2
)γμ
γ5
+ FP(Q2
)q μ
γ5
]τ±
31. The axial mass MA puzzle
QE scattering at O(GeV) needs to take into account the nucleon structure:
31
jμ
= [FV
1 (Q2
)γμ
+ i
κ
2M
FV
2 (Q2
)σμν
q ν − FA(Q2
)γμ
γ5
+ FP(Q2
)q μ
γ5
]τ±
Vector - OK
(from electron scattering)
Pseudoscalar - small
(~ml/M)2
32. The axial mass MA puzzle
QE scattering at O(GeV) needs to take into account the nucleon structure:
32
jμ
= [FV
1 (Q2
)γμ
+ i
κ
2M
FV
2 (Q2
)σμν
q ν − FA(Q2
)γμ
γ5
+ FP(Q2
)q μ
γ5
]τ±
FA(Q2
) =
1.267
(1 + Q2/M2
A)
2
Old (pre-1990) average:
Newer measurements (K2K, MINOS,
MiniBooNE…etc) are higher, up to ~1.35 GeV
MA = 1.03 ± 0.02 GeV
12C
39. How to measure the mass of the neutrino?
⇡+
! µ+
+ ⌫µ
(in a model independent way)
40. How to measure the mass of the neutrino?
• Finding the missing mass at accelerator. For example:
• Energy-momentum conservation says (for pion decay at
rest):
• How well can the momentum of the muon be measured?
At an experiment at PSI [Phys. Rev. D53, 6065 (1996)], it was
measured to ~ 4 ppm:
⇡+
! µ+
+ ⌫µ
m2
⌫µ
= m2
⇡+ + m2
µ+ 2m⇡+ (m2
µ+ + p2
µ+ )1/2
pµ+ = (29.79200 ± 0.00011) MeV/c
Not good enough !
(when you want to measure neutrino mass to sub-eV level) !
41. Determining the neutrino mass from β endpoint
Z Q
Q E
dN
dE
dE ⇡ 2
✓
E
Q
◆3
Only a tiny fraction of decays will end up near the endpoint
An ideal isotope would have very small Q
43. Neutrino mass limit from beta-decays
Wilkerson 2012
Tritium β-decay
(12.3 yr half-life)
44. Neutrino mass limit from beta-decays
Wilkerson 2012
Mainz (2005, final result)
m(νe) < 2.3 eV (95% CL)
C. Kraus et al., EPJ C40:447
Troitsk (2011, re-analysis)
m(νe) < 2.05 eV (95% CL)
V. N. Aseev et al., PRD 84:112003
45. Another way to “see” the beta-electrons
45
! =
!
=
qB
me + E
coherent cyclotron radiation
Asner et al., PRL 114 (2015) 162501
83mKr test
47. Seeing the cosmic neutrino background
47
Tν = 1.95 K
Tγ = 2.725 Kcf
The energy is so low
HOW?
per (neutrino+antineutrino) species
48. Seeing the cosmic neutrino background
48
Tritium and other isotopes studied for relic neutrino capture in:
Cocco, Mangano, Messina, JCAP 0706 (2007)015
Neutrino capture on Tritium
With 100 g of tritium, event rate is
~O(10) events per year
49. Seeing the cosmic neutrino background
49
Neutrino capture on Tritium
Gap (2m) constrained to < ~0.6eV
from Cosmology
(some electron flavor expected with
2m>0.1eV from neutrino oscillations)
What do we know?
Tritium β-decay
Endpoint (Q)
Challenges:
• Energy resolution
• Background
• Triggering on the electrons
near endpoint
Tully 2017
Supported by:
The Simons Foundation
The John Templeton Foundation
PTOLEMY (R&D)
50. • Long baseline neutrino experiments
(CP violation and neutrino mass
hierarchy)
• Neutrino astronomy
• Neutrinoless double beta decays
• Sterile neutrinos
(from reactor and beam experiments)
• Neutrinos in cosmology….
But I have covered how to “see” the neutrinos in the energy ranges of the
sources in Slide 3, so you can explore these additional topics on your own.
[10-27cm2]
Neutrino topics that I didn’t cover (many):
51. References
• Christine Sutton, Spaceship Neutrinos, Cambridge
University Press (1992).
• H. Gallagher et al., Neutrino-Nucleus Interactions,
Annu. Rev. Nucl. Part. Sci. 61, 355 (2011).
• J. A. Formaggio and G. P. Zeller, From eV to EeV:
Neutrino cross sections across energy scales, Rev.
Mod. Phys. 84, 1307 (2012).
• T. W. Donnelly et al., Foundations of Nuclear and
Particle Physics, Cambridge University Press (2017).
51
64. Considerations
• Preferably:
• high isotopic abundance
• high efficiency
• large mass
• long exposure
• low background
• good energy resolution
There is not an
obvious choice
of isotope or
detector
technology
