21st european cosmic ray symposium kosice september 11th 2008 catia grimani and michele fabi urbino...

21st European Cosmic Ray Symposium Kosice September 11th 2008

Catia Grimani and Michele Fabi

Urbino University and INFN Florence

The potentialities of LISA as an observatory for solar and cosmic-ray physics at 1 AU far from Earth

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Summary

LISA-PF & LISA missions & orbits Radiation monitors on LISA-PF Solar and Cosmic-ray Physics on board LISA Conclusions


LISA & LISA-PF LISA Michelson Interferometer in space for

gravitational wave detection down to 0.01 mHz:

3 S/C located at 5x106 km from each other near the ecliptic plane; 50x106 km behind the Earth Optical telescopes and inertial sensors Acceleration limit requirement: 3x10-15

m s -2 Hz-1/2

Launch expected in 2018- Duration 2-10 years

LISA-PF Demonstration mission for

LISA: two test masses placed at a distance of 30 cm

L1 orbit One order of magnitude below

the LISA requirements Launch expected in 2011

Km


LISA SCIENTIFIC GOALS


LISA-PF ORBIT


LISA IN SPACE


LISA orbit characteristics Distance from the Sun 0.9933 - 1.0133 AU Latitude off the ecliptic 0.7o - 1.0o

Longitude difference with respect to Earth 19o - 21o


LISA Inertial sensor and test mass

VACT1

VACT2

VM

Csens1

Csens2

VAC

100 kHzL

L

Cp

Cp


Radiation monitors (RM) will be placed on board the LISA spacecraft

RM design has been finalized for the PF only


SKETCH OF PARTICLE DETECTOR FOR LISA-PF

1.4 cm

1.05

cm 2 cm

2 layers of silicon detectors Dimensions: 1.05 x 1.4 cm2

Thickness: 300 mLobo, 2004

Geometrical factor: One layer - 9.24 cm2 sr Coincidence - 0.87 cm2 sr

Copper box 6.4 mm thick


Detector Positioning on LISA-PF

Ecliptic

Sun

EarthSpacecraft

Solar Panels

Spacecraft

to Sunto Earth

Radiation Monitor front plane


Present RM characteristics

Galactic proton and helium nuclei (no 3He and 4He separation) in the whole energy range monitoring

SEPs above 70 MeV/n (p, He) monitoring Overall countrate on each silicon detector Ionization energy losses in the rear detector for

coincidence events only (50 keV-5 MeV) Maximum fluence 108 particles/cm2


Galactic cosmic-ray variations and fluctuations Long-term variations 11-year variation (Sun Spots) 22-year opposite Global Solar Magnetic Field (GSMF) Polarity change Quasi-biennial variations

Short-term fluctuations Forbush decreases 27-day variation Minutes - hours (Observed by two different experiments at the same time: HIST on

POLAR and on INTEGRAL) see http://astro.ic.ac.uk/pwass/thesis/pjwThesis2 Shaul et al., 2006


Solar Modulation and

Global Solar Magnetic Field Polarity

Alanko-Huotari, Mursala, Usoskin and Kovaltsov, Solar Physics, 238, 391, 2006


Cosmic-ray proton observations during the last two solar cycles

CG et al. 30th ICRC 2007 Merida Mexico


Solar Modulation of Galactic Cosmic Rays

Gleeson and Axford, Ap. J., 154, 1011, 1968

J(r,E,t) J(∞,E+)=

E2-Eo2 (E2-Eo

2

J: particle flux

r: distance from Sun

E: particle total energy

t: time

Eo= particle mass

= particle energy loss from infinity (different for each species)

Ok for positive polarity epoch data only!


Reduction factors

Solar minimum - negative polarityR1=1+(0.4/1.602)*logE+(0.4/1.602)-0.4 0.1<E<4.0 GeV(/n)

High solar activity - negative polarityR2=0.61+1.41*E-1.2*E1.32+0.146*E1.95 0.1<E<1.6 GeV(/n)


Solar polarity effect on GCR p, He, e- and e+

p

He

Boella G. et al., J. Geophys. Res. 106:355 2001

CG et al. 30th ICRC 2007 Merida MexicoCG, A&A, 474, 339, 2007


Solar modulation during the next two solar cycles

D. Hathaway and Dikpati M. http://science.nasa.gov/headlines/y2006/10may_lagrange.htm


Positive polarity cosmic-ray flux parameterization

F[E(GeV)]=A(E+B)-EParticles/(m2 sr s GeV)

A B

P (BESS97)

He(BESS97)

18000

850

1.09

0.915

3.66

3.17

0.87

0.42

P (BESS00)

He(BESS00)

18000

850

1.71

1.25

4.20

3.60

1.41

0.85

P(MASS89) 18000 1.57 3.95 1.16

P(BESS02) 18000 1.60 3.99 1.20

(Papini, CG & Stephens, Il nuovo Cimento, 19, 367, 1996; CG et al., CQG,21,S629, 2004)


GCR p and He fluxes at the time of the LISA missions

CG et al., XXX International Cosmic-Ray Conference, Merida, Mexico July 2007CG et al., 7th Amaldi Conference Sidney Australia July 2007 presented by D. TombolatoCG and M. Fabi, Ionizing Radiation Detection and Data Exploitation Workshop, ESA/ESTEC, October 2007


Part. A B Reduction Factor

LISA-PF

Positive

Polarity

p

He

18000

850

1.6

1.15

3.99

3.45

1.20

0.70

LISA-PF

Negative

Polarity

p

He

18000

850

1.6

1.15

3.99

3.45

1.20

0.70

R1(E)

0.1<E<1.6

GeV

LISA 2018 p

He

18000

850

1.09

0.915

3.66

3.17

0.87

0.42

LISA 2022 p

He

18000

850

1.27

0.99

3.66

3.17

0.87

0.42

R2(E)

0.1<E<4.0

GeV

Proton and Helium flux parameterization at the timeof the LISA missions


Count rate and test-mass charging for the LISA missions (FLUKA Monte Carlo simulation)

Mission Part. Test-Mass

Charging

(%)

Part. Radiation

Monitor

Countrate

(%)

LISA-PF

Positive

Polarity

p

4He

3He

0.17

0.17

0.21

p+4He+3He 0.40

LISA-PF

Negative

Polarity

p

4He

3He

0.13

0.11

0.18

p+4He4+3He 0.38

LISA Sol. Min.

2018

Positive Polarity

p

4He

3He

1.0

1.0

1.0

p+4He+3He 1.0

LISA Sol. Max.

2022

Negative Polarity

p

4He

3He

0.53

0.50

0.51

p+4He+3He 0.65

For absolute rates see Araujo et al. Astr. Phys., 22, 451, 2005


SOLAR FLARES (Reames, 1997)

Electron rich3He/4He =1Fe/O = 1H/He = 10QFe = 20Duration = hoursLongitude = 40-70Radio Type = III,V(II)X-rays = ImpulsiveEvents/year = about 1000

IMPULSIVEGRADUAL (CMEs)

Proton rich3He/4He =0.0005Fe/O = 0.1H/He = 100QFe = 14Duration = daysLongitude = more flat Radio Type = II,IVX-rays = GradualEvents/year = about 10

ONLY 1-2% of CMEs produce Solar Energetic Particles


ESTIMATE OF NUMBER OF YEARLY SEP EVENTS DURING THE NEXT DECADE

Various methods are available in literature: Nymmik, 1999

We have estimated the yearly SEP-event number in the fluence range 106-1011 protons/cm2

above 30 MeV considering high and low solar cycle projections.

Nymmik has found a correlation between the yearly number of SEP events and the number of yearly predicted solar spot number:

NSEPs [NSSmin,NSSmax]=0.0694 NSS[min,max]

Nymmik has found that the number of SEP events show a power-law trend as a function of fluence

dNSEPs=C e- d

Where =4x109

and C was determind on the basis of the total number of expected SEP events


Number of yearly expected solar spots during the next solar cycles

Year Minimum SS #

Maximum SS #

2009 9 39

2010 36 127

2011 57 220

2012 68 195

2013 67 149

2014 54 122

2015 44 88

2016 24 63

2017 11 16

2018 5 15

Solar Cycle 24

Year Average SS #

2019 4

2020 17

2021 37

2022 56

2023 63

2024 60

2025 50

2026 37

2027 23

2028 11

2029 5

Solar Cycle 25


During the LISA-PF mission (6 months) we expect 4.4 events in the fluence range 106-109 protons/cm2


Minimum number of SEP events expected during the next decade

106 - 107 p/cm2

107 - 108 p/cm2

108 - 109 p/cm2

109 - 1010 p/cm2

1010 - 1011 p/cm2


Maximum number of SEP events expected during the next decade

106 - 107 p/cm2

107 - 108 p/cm2

108 - 109 p/cm2

109 - 1010 p/cm2

1010 - 1011 p/cm2


Average number of SEP events expected during the solar cycle 25

106 - 107 p/cm2

107 - 108 p/cm2

108 - 109 p/cm2

109 - 1010 p/cm2

1010 - 1011 p/cm2


Storini et al., 2008

Gnevyshev gap in Sunspot Area


Storini et al., 2008

Gnevyshev gap in SEP parameters


Taking into account the Gnevishev Gap, the total number of expected SEP events might be reduced by 25% in the year(s) of the very solar maximum


LONGITUDE DEPENDENCE OF SOLAR EVENTS•Large CME shocks might cause flat longitude profiles•In the western flank of the shock the event is more dynamic than the rest of the CME •For central and eastern SEP events invariance begins after shock passage

Figure from Reames, 2002


RADIATION MONITOR EXPECTED PERFORMANCE


We expect a SEP flux difference among the LISA satellites associated with the same event ranging between 5 and 10%.This estimate was carried out on the basis of observed, energetic, proton fluxes related to gradual events differing by a few degrees in solar longitude.Further investigation is needed in order to take into account the role of different boundary conditions for

each event.

SEP FLUX AT SMALL STEPS IN LONGITUDE ABOVE 100 MeV


Central-eastern event

Western event

Expected count rate variation on each silicon wafer


Flare September 29th 1989

Flare February 16th 1984

Flare May 7th 1978

Figures fromGrimani&VoccaPHOEBUS Proposal; 2004

SOLARENERGETICPARTICLES


Expected count rate on one silicon layer

0

500

1000

1500

2000

2500

3000

3500

4000

GPm GPM F1 F2 F3

Flux1

Flux2

Flux3

Flux4

Flux5

Cou

nt r

ate

GPm:galactic protons at solar minimumGPM:galactic protons at solar maximumF1: Flare 7 May 1978F2: Flare 16 February 1984F3: Flare 29 September 1989


Expected count rate on both silicon layers

0

50

100

150

200

250

300

350

GPm GPM F1 F2 F3

Flux1

Flux2

Flux3

Flux4

Flux5

Cou

nt r

ate

GPm:galactic protons at solar minimumGPM:galactic protons at solar maximumF1: Flare 7 May 1978F2: Flare 16 February 1984F3: Flare 29 September 1989


GALACTIC AND SOLAR PARTICLE IONIZATION ENERGY LOSSES

IN PARTICLE MONITORS


ROLE OF ELECTRONS ON BOARD LISA


CG et al., in preparation

BEST-LINE FIT TO THE INTERPLANETARY ELECTRON SPECTRUM DURING A POSITIVE POLARITY PERIOD

Jovian maximum

Jovian minimum


BEST-LINE FIT TO THE INTERPLANETARY ELECTRON SPECTRUM DURING A NEGATIVE POLARITY PERIOD

Jovian maximum

Jovian minimum

Solar electron fluxes

Flare September 7th 1973Flare November 3rd 1973


SEP FORECAST

Posner (2007) has developed a method for SEP event forecasting.Electron fluxes of solar origin in the energy range between 0.3 and1.2 MeV reach 1 AU always BEFORE energetic protons in the energy range <50 MeV.

INTERPLANETARY ELECTRONS, INCLUDING SOLAR, ACCOUNT FOR 5% AND 13%, RESPECTIVELY, OF PROTONSAT SOLAR MINIMUM AND MAXIMUM RESPECTIVELYON THE RM COUNT RATE AND REDUCE 15% THE NET TEST-MASS CHARGING WHILE INCREASE OF 8%THE SHOT NOISE AT SOLAR MINIMUM, TWICE THIS VALUE AT SOLAR MAXIMUM … MORE THAN THIS…ELECTRONS ALLOW…


(*) The intensity increase of both electrons and protons are correlated

(*) Both are correlated to the longitude between the observer and the flare

(*) Timescales of electron intensity increase are of tens of minutes.

(*) Protons above 100 MeV can be forecasted through the detection of 1 MeV electrons. Delay time of protons with respect to electrons range between 10 minutes and 1 hour.


Time delay between solar electrons and protons


Conclusions

Particle monitors on board LISA missions will provide precious clues on solar and cosmic-ray physics

LISA will allow us to map SEP fluxes above 100 MeV(/n) as a function of time at small steps in longitude.

An electron monitor for SEP forecasting would be recommended on LISA.


ESA and Space Weather

One man’s noise is another man data III Space Weather Week Brussels -Belgium November 13th-17th 2006

Our proposition to use LISA RM for solar physics and space weather investigations is now officially part of the ESA program for future space weatherinvestigations.

From the talk by E. Daly (ESA space environment specialist,Head of Space Environment Effects Analysis Section):


Thank you for your attention!

21st european cosmic ray symposium kosice september 11th 2008 catia grimani and michele fabi urbino...

Documents

potentialities of lisa

lisa requirementslaunch

solar physics

solar polarity effect

solar cyclescg

solar cyclesd

cosmicray physics

lisa spacecraft rm design