1. Superconducting detectors LDRD meeting July 1 st 2015 Alexandre Camsonne

2. High level summary Goal of the project Use JLab SRF and ARC resources to produce NbTiN superconducting detectors Deliverable Superconducting detectors have potential to sustain rates from 100 MHz to 1 GHz, up to 10 times better than current detector technologies, and might have better aging and radiation hardness Benefits to the laboratory Enable high rate experiments not possible or limited with current technology Local production of detector and simple technology makes it a viable alternative to expensive silicon detectors Develop expertise in superconducting nanostructure for development of high performance detectors and electronics 2

3. Thin superconducting stripe of 5 to 10 nm thickness Meander geometry to maximize surface, typical width of strip fews tens nm and length a few hundreds nm Signal speed depends on material, substrate and geometry ( inductance ) Energy sensitivity depends on width and thickness Mostly developed for astrophysics and telecommunication with IR sensitivity : Nasa Jet Propulsion Laboratory, Lincoln Laboratory …. Superconducting nanowire technique 3

4. Superconducting detector principle Review : Chandra M Natarajan et al 2012 Supercond. Sci. Technol. 25 063001 doi:10.1088/0953-2048/25/6/063001doi:10.1088/0953-2048/25/6/063001 Single Superconducting Nanowire Photon Detectors : SNSPD 4 Detector biased close to critical current

5. Features of SNSPD Fast : Typical 10 to 1 ns wide ( highly dependent on material and geometry ) potentially few picosconds pulse width ( YBaCuO microbridge) much faster than photomultiplier Not based on ionization ( different aging properties ) most likely longer lifetime than PMTs Sensitivity can be tuned by varying thickness and width : X-ray sensitivity to IR, detection of low energy particles which stops in detector Detection efficiency –20 % typical around 50 % with optical cavity and up to 93 % with WSi x (Detecting Single Infrared Photons with 93% System Efficiency F. Marsili et al ) Very good timing resolution : at least 100 ps up to 30 ps maybe better limited by readout electronics ( Dauler E A, Kerman A J, Robinson B S, Yang J K W, Voronov B, Goltsman G, Hamilton S A and Berggren K K 2009 Photon-number-resolution with sub-30-ps timing using multi-element ) 5

6. SNSPD at JLab Need thin superconducting film –SRF group Anne-Marie Valente is leading R&D for think film superconducting : all the infrastructure and expertise for NbTiN is available Need lithography technique –ARC ODU engineering laboratory Pr. Gon Namkoong is developping organic solar cells at the ARC laboratory Need detector characterization techniques –Electron microscopy also available in ARC –Vertical Test Area used already for cool down of SRF samples –Cryogenic targets available in Halls for in situ and irradiation tests A lot of expertise and infrastructure to produce the detector is available locally ! sapphire substrate NbTiN sputtering resist polymer PMMA e beam ions dissolve Resist processing and electron beam lithography Dissolve non irradiated resist Reactive ion etching to remove uncovered metal Dissolve remain of resist 6 e beam NbTiN target hardened resist

7. Goals of project Develop NbTiN UV/visible SNSPD Detector optimization : –speed and efficiency –High resolution timing –Minimum ionizing detector –MIP insensitive recoil detector Amplification using avalanche scheme Test and design optimization for magnetic field Evaluation of effect of radiation on detector properties, determination of radiation hardness 7

8. Timeline First quarterSecond quarterThird quarterFourth quarter Year1 Order cryo stand Evaporation NbTiN samples Start electron beam lithography IR SNSPD Setup test stand Integrate superconducting amplification to IR SNSPD Detector testing Produce SNSPD with IR sensitivity Detector testing Year2 Reactive Ion Etching setup order Irradiation of detectors Detector production UV/visible MIP Deuteron Irradiated IR SNSPD detector testing Detector testing Test substrate Irradiation of new detectors Year3 Order large spectrum laser Test properties of irradiated detectors Efficiency of detectors as a function of wavelength Test in magnetic field Test in Helium bath Papers Performances of detectors Radiation hardness Feasibility MIP 8

9. Budget CATEGORY LDRD REQUEST FY15 ($) LDRD REQUEST FY16 ($) LDRD REQUEST FY17 ($) TOTAL ($) Labor - Fringe26,49027,28428,10381,877 Labor - Non-Fringe 27,000 54,000 Fringe13,77514,18814,61442,577 Stats2,3314,7774,84911,957 Total for Personnel42,59673,24974,566190,411 Materials and Supplies < $50K13,00029,50020,40062,900 Equipment < $50K50,00070,000 190,000 Direct Costs > $50K94,00025,00035,000154,000 Total Direct Costs199,596197,749199,966597,311 G&A52,79886,37582,483221,656 Total Indirect Costs52,79886,37582,483221,656 TOTAL LDRD REQUEST252,394284,124282,449818,967 TOTAL BUDGET 818,967 ItemDirect cost (K$) Probe station144 Reactive Ion Etcher 75 Laser85 56 substrates12 Supplies50 Man power136 Amplifier10 Bias supply20 Major items 9

10. Project manpower PI : Alexandre Camsonne 0.25 FTE/year Anne-Marie Valente : 80 hours / year ODU : one graduate student for 2 years supervised by Dr. Gon Namkoong 10

11. Outlook Test of other superconducting compound –Faster response time –Higher Tc –Better radiation hardness Test substrates –Improve relaxation time –Low Z, low cost –Metal –Multilayer detectors Development superconducting electronics Development of large multielements detector Mass production technique : X-ray lithography 11

12. Conclusion Jlab is an ideal place to develop superconducting detector –expertise in superconductor thin films in SRF –local nanofabrication expertise at ARC –Cryogenics : Vertical Test Area –Target group : irradiation and integration in target Detectors have potential to be fast, radiation hard, could be produced locally making it a potential cheap alternative to silicon Detector could enable experiments not possible now or improve efficiency of large acceptance detectors Potential for growth and a lot of future R&D –MgB 2 development –Test substrates and superconductors to improve speed –Large area detectors –UV/X-ray lithography using accelerator of FEL or accelerator –Superconducting electronics 12

13. Backup 13

14. Response to commitee The “Approach/Method” section lacks the basic components of a proposal such as a background on the state of the art of the technology (1), specific aims(2), detailed research plan, clear milestones(3), proof of experience of the researchers, adequacy facilities to accomplish and commitment from the partners to achieve the goals(4). As stated before the proposed work is to build upon existing state of the art superconducting nanowire detector presently able to detect IR photons. The PI doesn’t explain why the proposed use of NbTiN will impart UV sensitivity (5).

15. Response to commitee The “Approach/Method” section lacks the basic components of a proposal such as a background on the state of the art of the technology (1) : slide number 5 specific aims(2) : slide 7 detailed research plan, clear milestones (3) : slide 8 proof of experience of the researchers, adequacy facilities to accomplish and commitment from the partners to achieve the goals(4). As stated before the proposed work is to build upon existing state of the art superconducting nanowire detector presently able to detect IR photons. The PI doesn’t explain why the proposed use of NbTiN will impart UV sensitivity (5).

16. ARC laboratory Lithography techniques Electron beam Joel 6060LV Scanning Electron Microscope (SEM) with electron beam lithography (EBL) Optical lithography Canon PLA 501F Mask Aligner Etching Reactive Ion Etching PlasmaTherm 790 reactive ion etcher (RIE) Microscopy High resolution field emission transmission electron microscope (HR-TEM) (JEM-2100F JEOL) with EDS Scanning electron microscope (SEM) (JSM-6060LV JEOL) with 3 nm resolution and EDS Hitachi S-570 Scanning Electron Microscope (SEM) Hitachi S-4700 Field emission SEM Collaboration ODU engineering group with Dr Gon Namkoong 16

17. Response to commitee proof of experience of the researchers, adequacy facilities to accomplish and commitment from the partners to achieve the goals(4). The superconductor NbTiN materials prepared on sapphire substrate will be patterned using electron beam lithography and reactive ion etching systems. Figure 1 shows ODU’ SEM system equipped with electron beam lithography (EBL). Particularly, EBL is a specialized technique for creating patterns with extremely high resolution of tens of nanometers and working with a variety of materials. The basic developing process using EBL includes the coating of a thin layer of resist that is chemically changed under exposure to the electron beam. And then he exposed and non-exposed areas will be developed either using a specific solvent or reactive ion etching system. Figure 1 (b) and (c) show one of examples that were developed using ODU’s electron beam lithography. In this project we will develop various device structures, which will have various dimension and structures of NbTiN superconductor materials. Dr. Namkoong from Old Dominion University has special expertise in this area to produce desired nanostructures using various technologies including lithography and conformal technologies. F igure 1(d) shows recently developed nanoplatforms of a dense ensemble of highly-ordered nanotubes which are composed of sequential semiconductor and metal nanotubes: TiO 2 (50 nm)/spacer (120 nm)/Pt-TiO 2 (25-25 nm)/spacer (120 nm)/Pt (50 nm). As demonstrated in Figure 1(d), large-scale production is indeed achieved which can facilitate nanoplatforms for numerous applications.

18. NbTiN, NbN, Mo 3 Re, V 3 Si coatings with Reactive Sputtering and High Power Pulse Magnetron Sputtering in self-sputtering mode & MgO coating with RF sputtering A unique, versatile thin film deposition system enabling multiple coating techniques in-situ Designed to enable rapid exploration of the production parameter space of: ▪Nb films ▪Alternative material films like NbN, NbTiN ▪S-I-S multilayer structures based on these compounds Jlab SRF From Dr. Anne-Marie Valente-Feliciano

20. Superconducting Thin Films @ SRF Lab Base pressure without baking 2x10 -9 Torr UV desorption system NEG chamber 3 magnetrons (DC, RF) Self-sputtered magnetron Ion source RGA chamber with differential pumping Thickness monitors

21. (5)Visible UV / sensitivity Threshold effect to get the nanowire non superconducting Wire latches with more energy Typically detection efficiency increases with photon energy until it does not deposit all its energy

22. Application to DVCS program Generalized Parton Distribution can give a spatial description of the nucleon Exclusive reactions needs to be measure to access GPDs ie DVCS Two main GPDs needed to access quark angular momentum H and E E accessible with –DVCS on transverse target –DVCS on deuterium target Hall A DVCS experiment en ->en  from subraction of deuterium and proton data Need recoil detector to disentangle the coherent DVCS from nDVCS signal Coherent DVCS on deuteron interesting to test en -> e  n = eD -> eD  – ep -> ep  though Contribution of coherent deuterium 22

23. General detector requirements Detector close to target to detect coherent deuteron –Cryotarget at 21 K : need to operate at low temperature –Direct view of target : high rate of photon, electrons, protons and neutron Need to be fast Radiation hard Possibly inside target for very low momentum recoil Investigated silicon detector but speed ( 1  s shaping )and radiation hardness not sufficient to run at a reasonable luminosity. Large acceptance detector is typical limiting factor to increase of luminosity ( Hall B, Hall A DVCS,…) Need fast and radiation hard detector Cryotatget ladder 23

24. Recoil detector for coherent DVCS  ∗ +D  ∗ + He4- > He4 +  D +  e- Recoil deuterium or He4 Cryotarget cell Superconducting detectors inside and outside target cell

25. Possible applications Recoil detector nDVCS –Size optimized for deuton, alpha : MIP blind recoil detector PMT replacement DVCS, SoLID Cerenkov : –need multipixels detector –Dedicated superconducting readout Cryogenic detector Need to investigate use in magnetic field for polarized target MIP tracker for SoLID 25

26. Detectors Liquid Helium Rich / scintillator PID detector Compton Nuclei Deeply Virtual Compton Scattering Doubly Virtual Compton Scattering Deeply Virtual Compton Scattering on transversely polarized target

27. Liquid Helium detector Helium has very fast UV scintillation and slower component Helium is transparent to UV RICH + scintillation + Time of flight Ionization, scintillation and Cerenkov Liquid helium flow SNSPD array

28. Application to SoLID for DDVCS Remove baffle Add materials and muon detector Tracker planes need low Z to reduce photon conversion 02/24/2015 28 Director's review SoLID DAQ A. Camsonne Vertex tracker close from target Tracker planes need low Z to reduce photon conversion

29. SNSPD typical properties detection efficiency as function of Wavelength and critical current Dark count rate as function of critical current for different temperatures Typical timing resolution of a NbN SNSPD Detector efficiency as a function of bias current for different temperatures 29

30. Superconductors properties L Parlato et al 2005 Supercond. Sci. Technol. 18 1244 doi:10.1088/0953- 2048/18/9/018doi:10.1088/0953- 2048/18/9/018 In boxes : active or future R&D at SRF group 30

31. YBaCuO detector P. Thoma Ultra-fast YBa2Cu3O7-x direct detectors for the THz frequency range 31 Superconducting nanobridge : direct observation of bunch length of THz radiation in the ANKA storage ring

32. Discriminator Characterization of superconducting pulse discriminators based on parallel NbN nanostriplines M Ejrnaes et al 2011 Supercond. Sci. Technol. 24 035018 doi:10.1088/0953-2048/24/3/035018 doi:10.1088/0953-2048/24/3/035018 32

33. Analog to Digital Converter 33

34. Photon counting sensor Similar to silicon PMT Very dense array of single photo sensor : number of photons simply equal to number of cells firing Multipixel SNSPD – 8 x8 produced Ideally 256x256 with digital readout electronics 64-pixel NbTiN superconducting nanowire single-photon detector array for spatially resolved photon detection Shigehito Miki,1,* Taro Yamashita,1 Zhen Wang,1,2 and Hirotaka Terai1 34

35. Superconducting strip detector Superconducting NbN Microstrip Detectors (1999 ) RD 39 Collaboration R. Wedenig and T.O. Niinikoski CERN et al Could see charged alpha ( can be used for recoil deuton ) But could not detect minimum ionizing particle because of electronics sensitivity ( use amplification scheme ) 35

36. Lithography techniques Visible / UV optical lithography Electron beam lithography X-ray lithography X-ray diffraction lithography This proposal focuses on maskless electron beam lithography for quick prototyping. Will have to investigate other techniques for mass production

37. Heliumless probe station Lakeshore probe station Heliumless system Cool down to 4 K Allows quick prototyping and testing of detectors Also facilitate SRF test by less reliance on cryogenics plant for testing

38. Reactive Ion Etching New setup in Test Lab Plasma Etch PE-100 Reactive Ion Etching CF4, SF6 Dedicated gas scrubber, can use Test Lab Scrubber Second option Add scrubber to existing RIE in ARC

39. Laser wide spectrum UV – visible laser 6 ps 390 to 800 nm

40. SNSPD at JLab Need detector characterization techniques –Electron microscopy also available in ARC –Vertical Test Area used already for cool down of SRF samples –Cryogenic targets available in Halls for in situ and irradiation tests Possibilty of development of large scale mass production technique R&D : FEL and accelerator can be source for UV or X-ray for high resolution optical lithography A lot of expertise and infrastructure to produce the detector is avalaible locally ! 40

41. JLab X-ray source in ARC 41 keV X-rays at 1 GeV Add pipe bypass LINAC Add ARC

42. Optimization of the detector efficiency Detector efficiency –Typical 20 % Rosfjord et al. “Nanowire Single-Photon Detector with an Integrated Optical Cavity and Anti-Reflection Coating.” Optics Express 14 (2006). F. Marsili, V. B. Verma, J. A. Stern, S. Harrington, A. E. Lita, T. Gerrits, I. Vayshenker, B. Baek, M. D. Shaw, R. P. Mirin, and S. W. Nam, "Detecting Single Infrared Photons with 93% System Efficiency," arXiv:1209.5774