Progetti futuri e nuove tecnologie:
sommario
Patrizia Cenci Sandra Leone
Ludovico Pontecorvo
XV IFAE Lecce 2003
Quali prospettive di fisica dopo LHC?
Quali altri progetti pongono sfide intellettuali/tecnologiche?
Quali rivelatori attualmente in costruzione sono particolarmente interessanti perche`
originali o innovativi
Quali sviluppi tecnologici sono promettenti per la comunita` di fisici delle particelle?
Quali applicazioni, pur non essendo direttamente
legate alla hep, utilizzano le stesse tecniche o
hanno tratto impulso da questa comunita`?
F. Piccinini
Prospettive di fisica a futuri acceleratori
F. Piccinini
F. Piccinini
Brevi richiami di fisica
P. Checchia
Rivelatore per un Linear Collider
Concetti generali del Rivelatore
P. Checchia
THE last results
G.Fogli et al., PR D66, 010001- 406,(2002)
The LMA solution for solar
neutrinos is confirmed The L/E oscillation pattern is confirmed
S. Gilardoni
Neutrino Factory
• Measure θ
13via P(ν
e→ν
µ) with a precision of 10
-3or setting a limit to 10
-6• Determine via MSW the sign of ∆m
2• Discover and measure the
CP violation in the leptonic sector (phase δ) P(ν
e→ν
µ) ≠ P(ν
e→ν
µ)
Need of high energy ν
e:
µ
+→e
++ ν
e+ ν
µPhysics at a Nufact
S. GilardoniSensitivity of Nufact
0.1o 1o 2.5o
5o
13o
S. Gilardoni
µ+ → e++ νµ +νe
νµ → µ− νµ→ µ+ Oscillation
Wrong Sign muons 1016p/s
3 1020 νe/yr 3 1020 νµ/yr
0.9 1021 µ/yr
S. Gilardoni
Around Europe...
• First possible location: Gran Sasso 732 km
• Second location: 3500 km away best Candidates: Svalbards (Norway)
Gran Canaria (Spain)
S. Gilardoni
To study gamma ray and cosmic ray in the MeV- GeV range you need to go outside the atmosphere
Why you want to study these items if you are a particle physicist?
• Nature of Dark Matter
(possible connection with supersymmetry)
• Quantum gravity limits
• Cosmic accelerators
• Matter antimatter asymmetry
Basic problem:
A. MorselliFisica delle particelle con rivelatori nello spazio:
Candidates for Galactic Dark Matter
• Massive Compact Halo Objects (MACHOs)
• Low (sub- solar) mass stars. Standard baryonic composition.
• Use gravity microlensing to study.
• Could possibly account for 25% to 50% of Galactic Dark Matter.
• Neutrinos
• Small contribution if atmospheric neutrino results are correct, since mν< 1eV.
• Large scale galactic structure hard to reconcile with neutrino dominated dark matter
• Weakly Interacting Massive Particles ( WIMPs)
• Non- Standard Model particles, ie: supersymmetric neutralinos
• Heavy (> 10GeV) neutrinos from extended gauge theories.
A. Morselli
EGRET data & Susy models
~2 degrees around the galactic center
EGRET data
A.Morselli, A.Lionetto, A.Cesarini, F.Fucito, P.Ullio, 2002
Annihilation channel b-bbar Mχ =50 GeV
background model(Galprop) WIMP annihilation (DarkSusy) Total Contribution
A. Morselli
A.Morselli, A.Lionetto, A.Cesarini, F.Fucito, P.Ullio, 2003
~2 degrees around the galactic center, 2 years data
(Galprop)
(one example from DarkSusy)
GLAST Expectation & Susy models
Annihilation channel W+W- mx=80.3 GeV
A. Morselli
Gamma-ray Large Area Telescope
GLAST
… 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 ...
Past, Present and Future Projects Past, Present and Future Projects
C 94
C
97 C 98 TS 93
M 89 M 91
MASS-89, 91, TS-93,
CAPRICE 94-97-98 PAMELA
PAMELA
NINA-2
NINA-1
NINA- 1
NINA- 2
SILEYE-2 SILEYE-
1
ALTEINO: SILEYE-3
ALTEA:
SILEYE- 4 SILEYE-
1
SILEYE- 2
SILEYE-
3 SILEYE- 4
GLAST
WiZard Program
AGILE
A. Morselli
AMS
AMS
Altezza: 320
Altezza: 320 - - 390 Km 390 Km Inclinazione 51.7°
Inclinazione 51.7°
A. Morselli
• Protoni fino ad alcuni TeV
• Antiprotoni fino a 200 GeV
• Elettroni fino al TeV
• Positroni fino a 200 GeV
• Nuclei fino ad alcuni TeV
• AntiNuclei fino al TeV γ fino a 100 GeV
• Isotopi leggeri fino a 20 GeV
Cosmic rays Cosmic rays Particle
Particle physics physics
H.E.
H.E.
astrophysics astrophysics
How do particles reach 1020 eV?
Bottom-up or top-down mechanisms ?
What are the origin and the acceleration mechanisms of Galactic cosmic rays ?
Where does the extragalactic component turn on ?
Spectrum and composition above 1 TeV up to 1018 eV.
The observed structures in the energy spectrum
...input to and from hadronic interaction models
Is there an upper end to the energy spectrum ?
A. Castellina
The Cosmic Ray Spectrum
Different techniques for different fluxes
The interesting structures
?
? ? ?
A. Castellina
AGASA correct No cut-off
Isotropy Clustering
UHEs come from Top-Down mechanisms
UHE are not hadrons but neutrinos
Lorentz invariance is violated
Origin in Local Supercluster (<50 Mpc)? [Sigl]
Strong magnetic field Æ isotropy
Magnetic lensing can create clustering
HiRes correct Cut-off
Origin from Bottom-Up mechanisms
Sources are cosmologically distributed
UHEcrs are hadrons
Top-Down models are excluded Charged particle astronomy
A. Castellina
AGASA/HiRes discrepancy:
AUGER Experiment
Argentina + Utah sites (each 3000 km2), E > 5 1018eV
1600 water tanks
(10m2 each)
6 fluorescence telescopes (10 m2 each)
At Mendoza site (AR):
A. Castellina
Physics Motivations Physics Motivations
In the
In the Standard ModelStandard Model with massivewith massive DiracDirac neutrinos neutrinos Lepton Lepton Flavour Violation processes
Flavour Violation processes (as(as µ →µ → eγγ, , τ τ →→ eγeγ, , µ µ →→ eee, eee, µ →µ → ee) are predicted ) are predicted at immeasurably small levelsat immeasurably small levels .. However,
However, Super Symmetric TheoriesSuper Symmetric Theories predict such processespredict such processes at much more reasonable ratesat much more reasonable rates..
Since the
Since the SM background is negligible, SM background is negligible, processes like processes like µ →µ → eγγ are clear evidences for Super Symmetryare clear evidences for Super Symmetry..
Problem:
Problem: are such rates are such rates experimentally observableexperimentally observable ??
(
~10−50)
F. Cei
L’Esperimento MEG:
SUSY Indications SUSY Indications
LFV processes especially sensitive to SSM grand unified theories (SUSY-GUT).
LFV induced by
LFV induced by finite finite sleptonslepton mixingmixing through
through radiativeradiative correctionscorrections..
Some predictions:
SUSY SU(5):
BR (µ → eγ) ≈ 10-14 ÷ 10-13 SUSY SO(10):
BRSO(10) ≈ 100 BRSU(5)
R.
R. BarbieriBarbieriet al.,et al.,Phys. Lett. Phys. Lett. BB338338(199(19944) 21) 2122 R. BarbieriR. Barbieriet al.,et al.,Nucl. Phys. Nucl. Phys. B445B445(1995) 215(1995) 215
F. Cei
Experimental Bound
Goal of MEG
Small (< 10) tan β values are highly disfavoured by recent combined LEP data. (hep(hep--ex/0107030)ex/0107030)
tan β = 30
Required Performances Required Performances
1 x 10 1 x 10--1313 1.2 x 10 1.2 x 10--1111 4.9 x 10 4.9 x 10--1111 1.7 x 10 1.7 x 10--1010
1 x 10 1 x 10--99 3.6 x 10 3.6 x 10--99
BRBR (90% CL) (90% CL)
20052005 19991999 19861986 19791979 19771977 19771977 YearYear
100100 2.5 x 10
2.5 x 1077 1919
4 0.15
0.8
MEGMEG
(6..7) (6..7) 2.5 x 10
2.5 x 1088 1717
1.61.6 4.54.5
1.21.2 MEGAMEGA
(6..9) (6..9) 4 x 10
4 x 1055 8787
1.31.3 88
88 Crystal Box
Crystal Box
6.46.4 2.4 x 10
2.4 x 1055 3737
1.91.9 88
8.88.8 LANLLANL
100100 2 x 10
2 x 1055 --
6.76.7 8.78.7
1010 TRIUMF
TRIUMF
100100 5 x 10
5 x 1055 --
1.41.4 9.39.3
8.78.7 SIN SIN
Duty Duty cycle (%) cycle (%) Stop rate
Stop rate (s(s--11))
∆θ∆θeγeγ (mrad(mrad))
∆∆tteeγγ (ns)(ns)
∆∆EEγγ/E/Eγγ (%)(%)
∆∆EEee/E/Eee (%)(%) Exp./Lab
Exp./Lab
Experimental sensitivity limited by spill-in of background (especially accidental) into signal region Æ high resolution measurements are needed. The accidental BR is
To obtain
To obtain BR (BR (µ →µ → eeγ)γ) ≈≈ 1010-13-13 we must havewe must have BRBRaccacc ≈≈ 3•3•1010-14-14 and this requires:and this requires:
eγ eγ
γ e
µ
acc R ∆E ∆E ∆θ ∆t
BR ∝ × × 2 × 2 ×
FWHMFWHM
F. Cei
Experimental Strategy Experimental Strategy
Use a high-intensity muon beam and
µ-decay at rest;
Measure γ time, energy and angle by using a fast & high- resolution e.m. calorimeter;
Measure e+ momentum by using a high-resolution spectrometer;
Measure e+ time by using fast counters (scintillator bars);
Use a trigger scheme based on the e+-γ coincidence.
1m
e+
Liq. Xe Scintillation Detector
γ
Drift Chamber Liq. Xe Scintillation
Detector
e+ γ
Timing Counter Stopping Target
Thin Superconducting Coil Muon Beam
Drift Chamber
¾ 800 l of Liquid Xenon
equipped with ≈ 800 PMTs;
¾ Homogeneous detector;
¾ Only scintillation light;
¾ Large light yield (~ NaI).
LXeLXe Calorimeter PerformancesCalorimeter Performances
Full MC simulationMC simulation Position
Position resolutionresolution:: Corresponding to:
Corresponding to:
Z-Z-coordinatecoordinate resolution: resolution:
mm
≈ 5
≈ y
x σ
σ
mrad 7
5 6 ÷
≈
≈σ . σϑ ϕ
mm
≈ 5
σ
ZF. Cei
••
“Golden modes”
Quattro “super-clean” inputs dalla fisica dei
K e dei B contribuiscono a verificare la descrizione della violazione di CP e il mixing dei quarks
d d s s d s
B B
B B x x
−
= −
ν ν π
→ 0
L0
K
E787/E949 (BNL) CKM (FNAL)
KOPIO (BNL) E391A (KEK)
BABAR, BELLE CDF, LHCB
ν ν π
→ + K+
d
K
sB → Ψ
d d s s d
s
B B
B B
x x
−
= − CDF, LHCB
BTeV
|V*ts Vtd|
Im (V*ts Vtd) ∝ η sin 2β
|Vts /Vtd|
G. Anzivino
L’esperimento KOPIO
Branching ratio previsto dallo SM (3 ± 1) x 10-11
Limite attuale < 5.9 x 10-7 (KTeV) (da π0 → e+e-γ)
Il decadimento K
L→ π
0νν
Sfida sperimentale posta da K
L →π
0νν
Segnatura sperimentale molto debole
Solo due fotoni rivelati
A priori non è noto il vertice di decadimento né l’energia del K
Fondi da controllare:
• Decadimenti del K
L 34% dei decadimenti del KL ha almeno un π0, per esempio KL
→
π0 π0 (BR = 9.3 x 10-4), KL→
π+ π− π0 (BR = 1.25 x 10-1) cattiva identificazione, es. KL
→
π− e+ ν (BR = 3.9 x 10-1)• Fondo di neutroni del fascio
• Decadimenti di iperoni, e.g. Λ →π
0n
G. Anzivino
Concetto dell’esperimento
fascio primario impulsato
impulso del KL con TOF π0 da KL → π0νν è ricostruito G. Anzivino
Risultati attesi: 41 eventi su 18.9 di fondo
dal “draft TDR”, per 500 gg di presa dati con 7 × 1013 ppp
SES ~ 10-12
Successive analisi indicano un
miglioramento ~ 25% legato a tecnicalità del fit geometrico
G. Anzivino
L. Grandi
WARP
L. Grandi
L. Grandi
S1 S2
Drift time
L. Grandi 14 MeV neutron gun measurements
M.I. Martinez
Si Drift Detectors di ALICE
SDD Layers
– Anodes along z – Drift along rφ
– 22 x 8 detectors in the outer layer – 6 x 14 detectors in the inner layer
Si Drift DetectorsSDD)
– r = 14.9, 23.8 cm → 1.3 m2 – 133 Kchannels
– rφ resolution 35 µm – z resolution 23 µm Silicon wafer: 300 µm thick
7.5x7 cm2 active area, 35 mm max drift length
Detector operation
Collection bias HV divider
ionizing particle
M.I. Martinez
Resolution
Beam test results for the resolution along the drift axis and anode axis from 2002 data
417 V/cm 667 V/cm
292 V/cm 542 V/cm
M.I. Martinez
Il sistema di TOF in ALICE
• Il TOF di ALICE identifica k, π, p prodotti nella regione centrale con impulsi da 0.5 a 2.5 GeV/c
• Caratteristiche fisiche del rivelatore:
– Risoluzione temporale <100ps – Alta efficienza >95%
– Alta granularità 105 canali in modo da consentire bassa occupancy 15%
– Garantire il funzionamento in presenza di rate elevati 50Hz/cm2
– Coprire un’area di circa 150m2
Scelta su rivelatori a gas MRPC Scelta su rivelatori a gas MRPC
A. Margotti
Perche` un MRPC a doppio stack?
Piazzola catodo segnale Piano resistivo (catodo)
Piani di vetro
Piano resistivo (anodo) Piazzola anodo segnale
6 gaps
3 gaps
3 gaps
Soluzione:
MRPC a
doppio stack
VANTAGGI:
• Tensione di lavoro bassa
• Impronta lasciata dalla carica sul pad più
concentrata
Piazzola catodo segnale Piano resistivo (catodo) Piani di vetro
Piano resistivo (anodo) Piazzola anodo segnale Piano resistivo (catodo) Piani di vetro
Piano resistivo (anodo) Piazzola anodo segnale
-HV
-HV +HV 0
-HV
A. Margotti
Esempio di MRPC a 6 gaps
Risultati del test beam – Ottobre 2002
Ottima uniformita` di prestazione in efficienza e risoluzione temporale
Efficienza ~ 99.9%
Risoluzione
temporale ~ 55 ps
Scan in tensione su una strip per verificarne l’uniformità in diversi pad.
Il plateau si raggiunge oltre i 12 KV:
A. Margotti
•Ogni strip è composta da 96 pads disposti su due file di 48 ciascuna.
•Le dimensioni di ogni pad sono 37x25mm e coprono un’area attiva di 1200x74mm.
Transition Radiator Detector (TRD)
X Detectors
(MWPC Xe-CO2)
Regular radiator: foils regularly spaced (CH2,Mylar) Irregular radiator: foam or fibres (C, CH2)
N. Mazziotta
TRD applications
Particle ID
Particle ID: is based on the threshold properties of the TR Energy measurement
Energy measurement: if the mass is known, the energy can be tagged only in the limited range between γth and γsat, and above γsat (below γth) it is possible only to set a lower (higher) limit
Charge measurement
Charge measurement: charge identification of high energy nuclei in particle astrophysics
N. Mazziotta
Sci-TRD
(proposed by B.Dolgoshein et al.)Possible solution to improve TRD rejection power Possible solution to improve TRD rejection power
• Two-component heterogeneous scintillation detector: small high Z (BGO) micro-granules into scintillation plastic bulk
• TR photons are absorbed mainly in high Z scintillation medium, but ionization from primary particle and long-range δ-rays is shared between the high Z and the plastic scintillator
• The signals from BGO and plastic can be separated due to big difference in decay times
• The Sci-TRD is interesting for space experiments because “no gas”
N. Mazziotta
Si-TRD
(proposed by P.Spinelli et al.)High Z gas detectors are typically used to detect TR X-rays Background = ionization energy loss of (non-)radiating particles
Few 10 µm pitch silicon strip det (SSD) can be used to well separate the particle from photons in short distances
Separation of the TR X-ray from the charged parent
particle track by means of a magnetic field
B field region
radiator
X-ray
particle
N. Mazziotta
~10 cm B ~ 1T
radiator
z axis
y axis
Si thickn.
≈ 300 ÷ 400 µm
Silicon single side
b-Physics with Particle Identification B
sK
+K
-Purity=13% Purity=84%
Efficiency=79%
No RICH With RICH
T. Bellunato
RICH di LHCB
radiator CF4 n (600 nm) 1.0005 pthreshold (π) 4.4 GeV/c
Np.e. 24
σθ 0.58 mrad p (3 σ) 100 GeV/c
RICH 1 RICH 2
radiator C4F10 Aerogel n (600 nm) 1.0014 1.03
pthreshold (π) 2.6 0.6 GeV/c Np.e. 32.7 6.6
σθ 1.45 2 mrad
p (3σ) 50 10 GeV/c
RICH layout
Flat mirror
PD plane
T. Bellunato
Aerogel as Cherenkov Radiator
Rayleigh scattering
linked network of SiO2 particles density = 0.15 g/cm
hygroscopic or hydrophobic
3
T. Bellunato
10 102
mm
mm
π run 30k events
9 GeV/c π
10 10 2
mm
mm
6 to 10 GeV/c π / proton
The Beam
π /p 6 GeV/c 30k events
Particle Identification Performance
T. Bellunato
Rivelatori
Rivelatori Bolometrici Bolometrici
bagno termico termometro cristallo
assorbitore particella
incidente
debole accoppiamento termico
∆T=E/C
Clattice ∼ T3 Celettroni ∼ T
T ∼ 10 mK
dielettrici e diamagnetici Bassa C
C. Bucci
Termometri:
termistori Ge NTD
Film Superconduttori Decadimento Doppio Beta:
Violazione del numero leptonico
Mibeta
Mibeta ( (
130130Te) Te)
5 moduli, 4 rivelatori ciascuno, alloggiati in una struttura
a torre (6.8 kg)
Dito freddo: 7 mK
La torre era circondata da uno schermo interno di
piombo Romano
Ogni rivelatore è un cristallo 3x3x6 cm3 di TeO2 (340 g)
C. Bucci
Risultati Risultati
Spettro di fondo in anticoincidenza dei 20 cristalli nella regione intorno all’energia del DDB0ν
Statistica totale ∼ 4.3 kg x y.
⋅
≥ 2 . 08 10
23anni 90 % CL
0 2 / 1
τ
ν mν ≤0.9−2.3eV*(
90% CL)
* In dipendenza dei valoriadottati per le matrici nucleari
C. Bucci
Cuoricino Cuoricino
Sezione piana
Dito freddo
Torre
Schermo di Pb Mixing chamber
This detector will be completely surrounded by active materials.
Substantial improvement in BKG reduction
11 moduli
4 rivelatori ciascuno Dimensione: 5x5x5 cm3
Massa: 790 g
2 moduli
9 rivelatori ciascuno, Dimensione: 3x3x6 cm3
Massa: 340 g
Total mass 40.9 kg
C. Bucci
•
Sensor element: Standard CMOS:• (High-resistivity silicon) (Low-resistivity silicon)
L. Servoli: Sviluppi recenti degli “Active Pixel Sensors IFAE – 23-26 Aprile 2003 - Lecce
How to implement a Monolithic Active Pixel Sensor (MAPS) ?
High-resistivity substate
(good for (good for standard standard siliconsilicon sensors) sensors) ÎÎmodificationmodificationof CMOS technologyof CMOS technology (only small structure (only small structure ~~1 mm1 mm2 2 active area)active area)
Low-resistivity substate
(standard CMOS
(standard CMOS technologytechnology) )
ÎÎmodificationmodificationof signal of signal generationgeneration and collectionand collection..
(current (current working working technique)technique)
Sviluppi di Active Pixel Sensors
L. ServoliHow APS works: the sensor side.
How APS works: the sensor side.
L. Servoli: Sviluppi recenti degli “Active Pixel Sensors”
IFAE – 23-26 Aprile 2003 - Lecce
80 e/h pairs /µm Î 200 - 2000 pairs
L. Servoli
Why we need (may
Why we need (may - - be) APS in HEP? be) APS in HEP?
Violazione del numero leptonico
L. Servoli: Sviluppi recenti degli “Active Pixel Sensors”
IFAE – 23-26 Aprile 2003 - Lecce
L. Servoli APS characteristic (1):
APS characteristic (1):
Lower power consumption (~~ 100 mW for ~~1Mpixel);
Spatial resolution (~~ 1 µm with analogue readout);
Radiation tolerance (inherent to deep submicron technology);
Low noise due to the closeness of the signal generation to the amplification stage;
Very low multiple scattering possible, reducing the thickness of the substrate.
Standard CMOS technologies (for mass-market consumer use:
videocameras, camera-on-a-chip) Î low cost , wide wafers (8” or 12“);
High integration (reduces fabrication complexity allowing the integration of several components on a chip);
Random pixel access (allows fast windowing on regions of interest)
The RAPS sensor.
The RAPS sensor.
• Same general line of APS with the following peculiarities:
• 0.18 µm CMOS technology;
• No epitaxial layer;
• Modified readout scheme (WIPS);
L. Servoli: Sviluppi recenti degli “Active Pixel Sensors IFAE – 23-26 Aprile 2003 - Lecce
A BNo-Epi With-Epi L. Servoli
DELOCALIZZAZIONE e BAND-GAP
Nonostante siano diversi dai cristalli inorganici, i semiconduttori organici possono anch’essi essere rappresentati da:
h+ e-
Eg
- livelli energetici (banda di valenza e di conduzione) separati da un gap energetico
- 2 portatori di carica, elettroni e lacune
M. Sampietro Rivelatori basati su semiconduttori organici
- Carbonio ibridizzato sp
2, struttura planare
- Legami σ nel piano e legami π fuori dal piano
.compartecipazione (delocalizzazione) degli elettroni π
.conduzione nel piano
PERCHE’ USARE
SEMICONDUTTORI ORGANICI ?
• Flessibilità meccanica,
• possibilità di coprire grandi superfici,
• emissione di luce nel visibile (… schermi),
• proprietà modificabili per via chimica,
• facilità di deposizione virtualmente su ogni tipo di substrato, anche attivo,
• buon matching dell’indice di rifrazione aria-rivelatore
M. Sampietro
Cr Au
quartz VBIAS
light
RF CF
VOUT
dithiolene
RIVELATORI per radiazione infrarossa I.R.
Layout
M. Sampietro
Ditioleni
SVILUPPI 2003
Il picco della risposta può
essere spostato con modifiche della struttura chimica
800 1200 1600 2000
0 20k 40k 60k 80k
absorption [a.u.]
λ [nm]
Pd neutral
Pd
reduced Ni
reduced
Tunable response
( Matching con la 2° e 3° finestra delle fibre ottiche )
2µs light pulse @ 470nm, V
BIAS=70V, L= 12µm
Cr Au
quartz VBIAS
light
RF CF
VOUT dithiolene
FOTORIVELAZIONE NEL VISIBILE
M. Sampietro
Cristallo scintillatore
Fodera di fotodiodo
(evenutalmente pixellata)
Il cristallo scintillatore (e quindi il fotorivelatore) può avere forma inusuale.
La struttura a pixel permette di acquisire anche la coordinata longitudinale di interazione
APPLICAZIONI con CRISTALLI SCINTILLATORI
M. Sampietro
Ruolo della Fisica per i Beni Culturali Ruolo della Fisica per i Beni Culturali
•
importanza in fase di conoscenza e diagnosi•
anche in fasedi intervento sull’opera
datazioni
analisi di composizione dei materiali
imaging
diagnosi dei problemi di deterioramento
quasi tutte le tecniche fisiche sono non invasive:
possibilità di indagine senza effettuare prelievi o comunque danneggiare l’opera
N. Grassi
Fisica Nucleare e Beni Culturali Fisica Nucleare e Beni Culturali
• Ion Beam Analysis (IBA)
con acceleratori o sorgenti
• Fluorescenza X (XRF)
analisi di materiali
•
Accelerator MassSpectrometry (AMS) datazioni con 14C
N. Grassi
Galileo: alcuni fogli Galileo: alcuni fogli
manoscritti non manoscritti non
datati
datati … …
note di esperimenti e calcoli…
…teoremi in bell’ordine, glosse,
sottolineature…
…sequenze di numeri e calcoli in disordine…
…correzioni e cancellature
N. Grassi
… … e uno datato: note di spesa nel e uno datato: note di spesa nel
Ms Ms .Gal.26 .Gal.26
N. Grassi
“ “ Datazione” Datazione”
del f.128
del f.128
Ms.Gal.72f.12818/10/1604
v(s), v(t), s(t)
N. Grassi
Progetto SPARC e Proposta SPARX per un SASE FEL
• Program for an Italian Coherent X-ray Source
• 1st phase(R&D): the Project SPARC @LNF-INFN 150 MeV Photo-injector R&D Project (LINAC) to investigate High Brightness e
-Beam Production
• 2nd phase: Proposal for a X-Ray laser SPARX:
(ENEA/CNR/INFN/Tor Vergata Univ.) aiming at
building a 2.5 GeV Linac driving a 1.5 nm SASE-FEL
L. Serafini
What is a SASE-FEL Radiation Source?
a Bright Electron Beam propagating through an Undulator
Spontaneous Radiation:
peaked at λr ≅ λu / 2γ2(1 + K2) ; γ ≥ 2.103 Beam rms divergence σ’≅ 1/γ ≅ 1 00 µrad
(Compton Backscattering of undulator virtual photons)
I r ≅ Ν e ; Ν e number of electrons per bunch (≅ 109)
Interaction of a bright electron beam with a stro ng optical field in an undulator magnet
results in a density modulation
of the electron bunch at the optical wavelength.
This leads to COHERENT EMISSION
L. Serafini
L. Serafini
Interaction of e- with Spontaneous Radiation causes Microbunching and SELF-AMPLIFICATION of Spontaneous Emission (SASE)
In the SASE mode the Intensity: I ph ≅ Ν eα α > 4/3;Ν e number of electr.(≅ 109) Amplification gives extraordinary High Photon Flux (diffraction limited beam) Beam rms divergence σ’≅ λ / 2πσe ≅ few µrad
- Free Electron Lasers operate routinely in the IR and UV region of the spectrum with optical resonators
- For wavelengths < ~ 200 nm
the reflectivity of mirrors deteriorates - Self-Amplified- Spontaneous-
SASE-FELs will allow an unprecedented upgrade in
Source Brilliance
Why a Coherent X-ray Source in Italy ?
Covering from the VUV to the 1 Å X-ray spectral range:
new Research Frontiers
SPARX
Intermediate between TTF-FEL (90-5 nm) and
TESLA-FEL (1 Å)
TTF
12.4 1.24 0.124 λ (nm)
L. Serafini
This Ultra-Bright Coherent Radiation (high peak brightness, ultra short(< 100 fs) radiation pulses) opens up new
Research Frontiers in several fields:
• Atomic physics
• Plasma and warm dense matter
• Femtosecond chemistry
• Life science
• Single Biological molecules and clusters
• Imaging / holography
• Micro and nano lithography
X-rays are the ideal probe for determining the structure of matter on the atomic and molecular scale
“Science with Soft X-Rays”, Nevill Smith, Physics Today, January 2001
L. Serafini