The early years-SSC - research.kek.jp research projectsresearch.kek.jp/people/kondo/myDocuments/The...
Transcript of The early years-SSC - research.kek.jp research projectsresearch.kek.jp/people/kondo/myDocuments/The...
The early years-SSC The Dawn of Silicon Detector Technology
Special session in honor of Professor Takashi Ohsugi
8th International "Hiroshima" Symposium on the Development and Application of Semiconductor Tracking Detectors (HSTD8)
Academia Sinica , Taipei, Taiwan
Dec. 5, 2011Takahiko KONDO (KEK)
2011/12/5 HSTD-8 symposium, T. Kondo 1
2011/12/5 HSTD-8 symposium, T. Kondo 2
S S Cthe Superconducting Super Collider
Once upon a time on the Earth, there was a project called
2011/12/5 HSTD-8 symposium, T. Kondo 3
SSC LHCEnergy 20 + 20 = 40 TeV 7 + 7 = 14 TeV
Luminosity 1033 cm-2s-1 1034 cm-2s-1
MR circumference 87.1 km 26.7 km
Bending field 6.55 T 8.33 T
Dipole magnets 8,652 1,232
Completion 1999, terminated 199820052008
Cost $4.4 B >$12 B ~ $10 B
Main accelerator parameters
The cost increase was the major reason of cancellation.
2011/12/5 HSTD-8 symposium, T. Kondo 4
Brief History of SSC
1982: Snowmass workshop
1984: Snowmass workshop, SSC CDG started.
1986: Snowmass workshop
1987: SSC Project approved by President Reagan
1989: Construction started at Waxahachie, Texas
1993: SSC demised in the middle of construction
2011/12/5 HSTD-8 symposium, T. Kondo 6
The major milestone forward was
Snowmass 1984 [1]
It became clear that all the tracking technique could not work at SSC. Secondary particles in SSC detectors are too dense, too fast and too high in radiation dose. Three proposals for new tracking devices:
1. Straw tubes2. Silicon strip detectors3. Scintillating fibers
[1] Proc. of the 1984 Summer Study on the Design and Utilization of SSC, June 23-July 13, 1984, Snowmass, Colorado
2011/12/5 HSTD-8 symposium, T. Kondo 7
G. Kramberger’s talk at DESY seminar
(2007.9.1)“Towards Radiation Hard Silicon Detectors at SLHC”
page 4
“Silicon strip detectors (near the beam pipe) appear to be limited to…≤ 1032....the 1032 limit could be optimistic.” (PSSC Summary Report pg. 130, 1984)
T. Kondo et al, Radiation Damage Test of Silicon MicrostripDetectors, pg. 612, Snowmass 1984
2007
2011/12/5 HSTD-8 symposium, T. Kondo 8
The prevailing opinion was that silicon vertex detectors were not possible at 1033.
M. Gilchriese’s talk at STD6 Tracking
Workshop(AbeFest), (2006.9.11)
“Silicon Detectors and the SSC”, page 4
This was quoted by Kramberger
1984
2011/12/5 HSTD-8 symposium, T. Kondo 9
M. Gilchriese’s talk at STD6 Tracking
Workshop(AbeFest), (2006.9.11)
“Silicon Detectors and the SSC”, page 6
However, there were indications already in 1984 that Silicon detectors could be more radiation tolerant and that cooling was desirable. (eg. T. Kondo et al.,…
1984
2011/12/5 HSTD-8 symposium, T. Kondo 10
T. Kondo et al, Proc. of the 1984 Summer Study on the Design and Utilization of SSC, June 23-July 13, 1984, Snowmass, Colorado, pp. 612-614
1984
I would be happy if you could refer this paper in your books and review papers in future.
Ra
2011/12/5 HSTD-8 symposium, T. Kondo 11
Radiation Damage Test of Silicon Microstrip DetectorsT. Kondo et al., PSSC, Snowmass 1984, pp. 612-614
HPK sensor : 30x30x0.2mm3, strip pitch 0.5 mm, ~10kΩ
1984
Photo of Radcolor film showing800 GeV proton irradiation profile.
Proton flux vs leak current.Steps due to beam profile changes
from Fig.6 of NIMA270(1988)42
2011/12/5 HSTD-8 symposium, T. Kondo 12
Before (T= 23oC) After 3.5x1014 p/cm2
by 800 GeV protons (T = 7oC)
(1) Silicon is rad-hard (2) little pulse-height change (3) cooling neededI was extremely delighted and excited by this new discovery !!
317 A/cm 102)C5.22( −⋅≈°α
1984Radiation Damage Test of Silicon Microstrip Detectors
T. Kondo et al., PSSC, Snowmass 1984, pp. 612-614
2011/12/5 HSTD-8 symposium, T. Kondo 13
M. Gilchriese’s talk at STD6 Tracking
Workshop(AbeFest), (2006.9.11)
page 10
Report of the Central Tracking Group, pg. 385 Snowmass 1986…………. Hence, our conclusion is that a silicon microstrip central tracking system is not realistic….
1986
2011/12/5 HSTD-8 symposium, T. Kondo 14
However, there were already indications of full silicon tracking concepts
A Proposal of Solid State Ball for SSC, T. Kondo et al, pg. 399, Snowmass 1986
1986
2011/12/5 HSTD-8 symposium, T. Kondo 15
1988 Radiation damage studies in Japan, Europe and US.Among others, two papers already published in 1988:
Radiation Damage in Silicon Microstrip Detectors, T. Ohsugi, ... T. Kondo, … K. Yamamoto .., Nucl. Instr. Meth. A265(1988)105
eV 20.1
)2
exp()( 2
=
−∝
ef
B
efg
ETk
ETTJ
They got a T dependence of bulk leakage current as
2011A. Chilingarov proposed
at RD50 Workshop, Liverpool, May 2011
eV 206.1=efE
23 years later !
2011/12/5 HSTD-8 symposium, T. Kondo 16
1988Radiation Damage Test of Silicon Multistrip Detectors, M. Nakamura,…T. Kondo, Nucl. Instr. Meth. A270(1988)42
using the irradiated sensor by 800 GeV protons in 1984.
Abstract:……. The effective impurity density decreases with fluence up to ~4x1013/cm2, but for greater fluences, it increases. This may indicate the type conversion of the bulk silicon ………
I think this is the first observation of type conversion in Si strip sensor, I think.
2011/12/5 HSTD-8 symposium, T. Kondo 21
1993SDC Collaboration meeting at KEK Japan, May 1993
….Taka, Akira, Shigeki, Aki, Yasuo, Nobu, Takashi, Youhei, Yorikiyo, Katsuya,…
Moishe
Tom
Larry
John
Harold
Gail
GeorgeGil Dan
Peter
Andris FredBrigg
Michelangelo
Abe
Henry
Dave Ye
Jim
2011/12/5 HSTD-8 symposium, T. Kondo 24
Epilogue 12011
ATLAS Barrel SCT leakage currentplot made by me (T. Kondo)
18 years later…See Dave Robinson’s talk for more details